CENTER FOR PAN ISLAMIC SCIENCE &amp; TECH. RESEARCH

https://neurosciencenews.com/sleep-brainwaves-flush-waste-25678/

·February 28, 2024

Summary: A new study unveiled a crucial role of sleep: brainwaves facilitating the cleansing of the brain by flushing out waste. This discovery not only underscores the brain’s non-dormant state during sleep but also highlights a sophisticated system where neurons’ synchronized activity powers the flow of cerebrospinal fluid, effectively removing metabolic waste and potentially neurodegenerative disease-causing toxins.

This insight opens up possibilities for enhancing brain cleaning processes to combat neurological diseases and improve sleep efficiency, hinting at a future where optimized sleep could lead to better health outcomes.

Key Facts:

1. Brainwaves Propel Cleansing Fluids: During sleep, neurons coordinate to produce rhythmic waves that drive the movement of fluid through the brain, washing away waste.

2. Potential for Disease Prevention: Understanding and enhancing this cleansing process could delay or prevent diseases like Alzheimer’s and Parkinson’s by ensuring the effective removal of brain waste.

3. Implications for Sleep Quality: This research suggests that improving the brain’s waste removal efficiency could allow for healthier brains even with less sleep, offering new avenues for treating sleep disorders and enhancing overall well-being.

Source: Washington University

There lies a paradox in sleep. Its apparent tranquility juxtaposes with the brain’s bustling activity. The night is still, but the brain is far from dormant. During sleep, brain cells produce bursts of electrical pulses that cumulate into rhythmic waves – a sign of heightened brain cell function.

But why is the brain active when we are resting?

Slow brain waves are associated with restful, refreshing sleep. And now, scientists at Washington University School of Medicine in St. Louis have found that brain waves help flush waste out of the brain during sleep. Individual nerve cells coordinate to produce rhythmic waves that propel fluid through dense brain tissue, washing the tissue in the process.

“These neurons are miniature pumps. Synchronized neural activity powers fluid flow and removal of debris from the brain,” explained first author Li-Feng Jiang-Xie, PhD, a postdoctoral research associate in the Department of Pathology & Immunology.

“If we can build on this process, there is the possibility of delaying or even preventing neurological diseases, including Alzheimer’s and Parkinson’s disease, in which excess waste – such as metabolic waste and junk proteins – accumulate in the brain and lead to neurodegeneration.”

The findings are published Feb. 28 in Nature.

Brain cells orchestrate thoughts, feelings and body movements, and form dynamic networks essential for memory formation and problem-solving. But to perform such energy-demanding tasks, brain cells require fuel. Their consumption of nutrients from the diet creates metabolic waste in the process.

“It is critical that the brain disposes of metabolic waste that can build up and contribute to neurodegenerative diseases,” said Jonathan Kipnis, PhD, the Alan A. and Edith L. Wolff Distinguished Professor of Pathology & Immunology and a BJC Investigator. Kipnis is the senior author on the paper.

“We knew that sleep is a time when the brain initiates a cleaning process to flush out waste and toxins it accumulates during wakefulness. But we didn’t know how that happens. These findings might be able to point us toward strategies and potential therapies to speed up the removal of damaging waste and to remove it before it can lead to dire consequences.”

But cleaning the dense brain is no simple task. Cerebrospinal fluid surrounding the brain enters and weaves through intricate cellular webs, collecting toxic waste as it travels. Upon exiting the brain, contaminated fluid must pass through a barrier before spilling into the lymphatic vessels in the dura mater – the outer tissue layer enveloping the brain underneath the skull. But what powers the movement of fluid into, through and out of the brain?

Studying the brains of sleeping mice, the researchers found that neurons drive cleaning efforts by firing electrical signals in a coordinated fashion to generate rhythmic waves in the brain, Jiang-Xie explained. They determined that such waves propel the fluid movement.

The research team silenced specific brain regions so that neurons in those regions didn’t create rhythmic waves. Without these waves, fresh cerebrospinal fluid could not flow through the silenced brain regions and trapped waste couldn’t leave the brain tissue.

“One of the reasons that we sleep is to cleanse the brain,” Kipnis said.

“And if we can enhance this cleansing process, perhaps it’s possible to sleep less and remain healthy. Not everyone has the benefit of eight hours of sleep each night, and loss of sleep has an impact on health.

“Other studies have shown that mice that are genetically wired to sleep less have healthy brains. Could it be because they clean waste from their brains more efficiently? Could we help people living with insomnia by enhancing their brain’s cleaning abilities so they can get by on less sleep?”

Brain wave patterns change throughout sleep cycles. Of note, taller brain waves with larger amplitude move fluid with more force. The researchers are now interested in understanding why neurons fire waves with varying rhythmicity during sleep and which regions of the brain are most vulnerable to waste accumulation.

“We think the brain-cleaning process is similar to washing dishes,” neurobiologist Jiang-Xie explained.

“You start, for example, with a large, slow, rhythmic wiping motion to clean soluble wastes splattered across the plate. Then you decrease the range of the motion and increase the speed of these movements to remove particularly sticky food waste on the plate.

“Despite the varying amplitude and rhythm of your hand movements, the overarching objective remains consistent: to remove different types of waste from dishes. Maybe the brain adjusts its cleaning method depending on the type and amount of waste.”

Your brain needs a really good lawyer

Sigal Samuel is a senior reporter for Vox’s Future Perfect and co-host of the Future Perfect podcast. She writes primarily about the future of consciousness, tracking advances in artificial intelligence and neuroscience and their staggering ethical implications. She also writes about how to make the world better for all of us now, from improving mental health to alleviating poverty to protecting nature.

Before joining Vox, Sigal was the religion editor at the Atlantic. Her work has also been published in outlets like BuzzFeed, the Daily Beast, the Rumpus, and Electric Literature. She has appeared on NPR, BBC, and CBC. Sigal is also the author of two award-winning books. Osnat and Her Dove, a children’s book, tells the true story of the world’s first female rabbi. The Mystics of Mile End, a novel, tells the story of a dysfunctional family dealing with mysticism, madness, and mathematics in Montreal. Sigal earned her MFA in creative writing from the University of British Columbia and her BA in philosophy from McGill University. Learn more about Sigal here.

Ethics Statement

Future Perfect coverage may include stories about organizations that writers have made personal donations to. This does not in any way affect the editorial independence of our coverage, and this information will be disclosed clearly when relevant.

Future Perfect is supported in part by grants from foundations and individual donors. Future Perfect prizes its editorial independence, and all editorial decisions are made separately from fundraising and commercial considerations. See Vox’s ethics and guidelines for more.

Your brain needs new rights

Rafael Yuste, a Columbia University neuroscientist, started to get freaked out by his own neurotech research a dozen years ago. At his lab, employing a method called optogenetics, he found that he could manipulate the visual perception of mice by using a laser to activate specific neurons in the visual cortex of the brain. When he made certain images artificially appear in their brains, the mice behaved as though the images were real. Yuste discovered he could run them like puppets.

He’d created the mouse version of the movie Inception. And mice are mammals, with brains similar to our own. How long, he wondered, until someone tries to do this to humans?

In 2017, Yuste gathered around 30 experts to meet at Columbia’s Morningside campus, where they spent days discussing the ethics of neurotech. As Yuste’s mouse experiments showed, it’s not just mental privacy that’s at stake; there’s also the risk of someone using neurotechnology to manipulate our minds. While some brain-computer interfaces only aim to “read” what’s happening in your brain, others also aim to “write” to the brain — that is, to directly change what your neurons are up to.

The group of experts, now known as the Morningside Group, published a Nature paper later that year making four policy recommendations, which Yuste later expanded to five. Think of them as new human rights for the age of neurotechnology:

1. Mental privacy: You should have the right to seclude your brain data so that it’s not stored or sold without your consent.

2. Personal identity: You should have the right to be protected from alterations to your sense of self that you did not authorize.

3. Free will: You should retain ultimate control over your decision-making, without unknown manipulation from neurotechnologies.

4. Fair access to mental augmentation: When it comes to mental enhancement, everyone should enjoy equality of access, so that neurotechnology doesn’t only benefit the rich.

5. Protection from bias: Neurotechnology algorithms should be designed in ways that do not perpetuate bias against particular groups.

But Yuste wasn’t content to just write academic papers about how we need new rights. He wanted to get the rights enshrined in law.

“I’m a person of action,” Yuste told me. “It’s not enough to just talk about a problem. You have to do something about it.”

Gut Bacteria May Play Role in Vision Loss

https://neurosciencenews.com/gut-bacteria-vision-loss-25660/

Speech Speed May Indicate Aging Brain Health

https://neurosciencenews.com/speech-speed-brain-health-aging-25661/

Researchers Overrate Their Ethical Practices

https://neurosciencenews.com/research-ethics-25667/

Unlocking the Brain’s Fear Circuitry: A Pathway to Survival Responses

https://neurosciencenews.com/fear-response-neuroscience-25656/

https://www.iqrasense.com/death-and-after-life/the-journey-of-a-muslim-believer-after-death-islamic-beliefs-according-to-hadith.html

Mapping the Brain’s ‘Dysfunctome’

https://neurosciencenews.com/dysfunctiome-brain-mapping-25651/

Relaxing Words Steer Sleep Quality

https://neurosciencenews.com/auditory-stimuli-sleep-25652/

Ultrasound Brain Stimulation: A Significant Leap in Neurotherapy

https://neurosciencenews.com/ultrasound-brain-stimulation-neurotherapy-25653/

Sleep, Circadian Rhythm, and Mental Health

Featured Neuroscience Psychology ·February 19, 2024

Summary: A new study highlights the critical link between sleep, circadian rhythms, and psychiatric disorders, suggesting that disturbances in sleep and internal body clocks can trigger or exacerbate mental health issues. The research underscores the prevalence of sleep-circadian disturbances across all psychiatric disorders, pointing to the need for holistic treatments that address these factors.

The review emphasizes the potential of new therapeutic approaches, such as light therapy and cognitive behavioral therapy for insomnia (CBT-I), to improve mental health outcomes. This work, incorporating insights from an international team, marks a step forward in understanding and treating psychiatric conditions by focusing on sleep and circadian science.

Key Facts:

Prevalence of Sleep-Circadian Disturbances: Sleep and circadian rhythm disturbances are commonly found across psychiatric disorders, with significant impacts on conditions like insomnia, bipolar disorder, and early psychosis.

Potential Mechanisms: The review explores mechanisms such as genetic predispositions, exposure to light, and changes in neuroplasticity that contribute to the link between sleep-circadian disturbances and psychiatric disorders.

Therapeutic Approaches: Highlighting the effectiveness of treatments like light therapy and CBT-I, the review suggests targeting sleep and circadian factors could lead to innovative treatments for psychiatric conditions.

Source: i) University of Southampton ii) https://neurosciencenews.com/sleep-circadian-rhythm-mental-health-25633/

Problems with our sleep and internal body clock can trigger or worsen a range of psychiatric disorders, according to a new review of recent research evidence.

The review, published today [19 February] in Proceedings of the National Academy of Sciences (PNAS), suggests gaining a better understanding of the relationship between sleep, circadian rhythms and mental health could unlock new holistic treatments to alleviate mental health problems.

“Sleep-circadian disturbances are the rule, rather than the exception, across every category of psychiatric disorders,” says Dr Sarah L. Chellappa from the University of Southampton, senior author of the review. “Sleep disturbances, such as insomnia, are well understood in the development and maintenance of psychiatric disorders, but our understanding of circadian disturbances lags behind.

“It is important to understand how these factors interact so we can develop and apply sleep-circadian interventions that benefit the sleep and mental health symptoms of patients.”

An international team of researchers from the University of Southampton, Kings College London, Stanford University and other institutions explored recent evidence on sleep and circadian factors, focusing on adolescents and young adults with psychiatric disorders. This is a time when people are most at risk of developing mental health disorders and when disruption to sleep and circadian rhythms are likely to occur.

Insomnia is more common in people with mental health disorders than in the general population – during remission, acute episodes and especially in early psychosis, where difficulty falling and staying asleep affects over half of individuals.

Around a quarter to a third of people with mood disorders have both insomnia and hypersomnia, where patients find it hard to sleep at night, but are sleepier in the daytime. Similar proportions of people with psychosis experience this combination of sleep disorders.

Meanwhile, the few studies looking at circadian rhythm sleep-wake disorders (CRSWD) suggest that 32 per cent of patients with bipolar disorder go to sleep and wake later than usual (a condition called Delayed Sleep-Wake Phase Disorder). Body clock processes (such as endogenous cortisol rhythms) have been reported to run seven hours ahead during manic episodes and four to five hours behind during the depressive phase. Timing is normalised upon successful treatment.

What are the mechanisms?

The researchers examined the possible mechanisms behind sleep-circadian disturbances in psychiatric disorders. During adolescence, physiological changes in how we sleep combine with behavioural changes, such as staying up later, getting less sleep on school nights and sleeping in on weekends.

Dr Nicholas Meyer, from King’s College London, who co-led the review said: “This variability in the duration and timing of sleep can lead to a misalignment between our body clock and our sleep-wake rhythms can increase the risk of sleep disturbances and adverse mental health outcomes.”

Researchers also looked at the role of genes, exposure to light, neuroplasticity and other possible factors. Those with a genetic predisposition towards a reduced change in activity levels between rest and wake phases are more likely to experience depression, mood instability, and neuroticism. Population-level surveys show self-reported time outdoors was associated with a lower probability of mood disorder. Sleep is thought to play a key role in how the brain forms new neural connections and processes emotional memories.

New treatments

Dr Renske Lok, from Stanford University, who co-led the review said: “Targeting sleep and circadian risk factors presents the opportunity to develop new preventative measures and therapies. Some of these are population-level considerations, such as the timing of school and work days, or changes in the built environment to optimise light exposure. Others are personalised interventions tailored to individual circadian parameters.”

Cognitive Behavioural Therapy for Insomnia (CBT-I) has been shown to reduce anxiety and depressive symptoms, as well as trauma symptoms in people experiencing PTSD.

In unipolar and bipolar depression, light therapy (delivered on rising in the morning) was effective compared with a placebo. Using it in combination with medication was also more effective than using medication alone. Other findings suggest light is effective in treating perinatal depression.

The timing of medication, meals and exercise could also impact circadian phases. Taking melatonin in the evening can help people with Delayed Sleep-Wake Phase Disorder to shift their body clock forward towards a more conventional sleep pattern and may have beneficial effects in comorbid psychiatric disorders. Nightshift work can adversely affect mental health but eating in the daytime rather than during the night could help, with research showing daytime eating prevents mood impairment.

The review also points to innovative multicomponent interventions, such as Transdiagnostic Intervention for Sleep and Circadian dysfunction (Trans-C). This combines modules that address different aspects of sleep and circadian rhythms into a sleep health framework that applies to a range of mental health disorders.

Dr Chellappa said: “Collectively, research into mental health is poised to take advantage of extraordinary advances in sleep and circadian science and translate these into improved understanding and treatment of psychiatric disorders.”

Funding: The research was funded by the Alexander Von Humboldt Foundation.

https://neurosciencenews.com/sleep-circadian-rhythm-mental-health-25633/

https://neurosciencenews.com/long-covid-brain-fog-25645/

AI Unlocks Secrets of Human Imagination and Memory Formation

Featured Neuroscience Open Neuroscience Articles

·January 19, 2024

Summary: A new study employs generative AI to shed light on how the human brain processes memories for learning, imagination, and planning. The study used a computational model resembling the hippocampus and neocortex’s neural networks to simulate memory encoding and retrieval.

This model demonstrated how the neocortex forms efficient conceptual representations from experiences, allowing for both the recreation of past events and the generation of new ones. The research highlights the brain’s ability to reconstruct memories with unique details, offering insights into memory’s role in survival and prediction.

Key Facts:

1. The AI model simulates the interaction between the hippocampus and neocortex in memory processing.

2. The neocortex forms “conceptual” representations, enabling the brain to recreate past experiences and imagine new scenarios.

3. The study provides insights into memory’s role in survival, predicting future events, and understanding memory distortions.

Source: UCL

Recent advances in generative AI help to explain how memories enable us to learn about the world, re-live old experiences and construct totally new experiences for imagination and planning, according to a new study by UCL researchers.

The study, published in Nature Human Behaviour and funded by Wellcome, uses an AI computational model – known as a generative neural network – to simulate how neural networks in the brain learn from and remember a series of events (each one represented by a simple scene).

The model featured networks representing the hippocampus and neocortex, to investigate how they interact. Both parts of the brain are known to work together during memory, imagination and planning.

Humans need to make predictions to survive (e.g. to avoid danger or to find food), and the AI networks suggest how, when we replay memories while resting, it helps our brains pick up on patterns from past experiences that can be used to make these predictions. Credit: Neuroscience News

Lead author, PhD student Eleanor Spens (UCL Institute of Cognitive Neuroscience), said: “Recent advances in the generative networks used in AI show how information can be extracted from experience so that we can both recollect a specific experience and also flexibly imagine what new experiences might be like.

“We think of remembering as imagining the past based on concepts, combining some stored details with our expectations about what might have happened.”

Researchers played 10,000 images of simple scenes to the model. The hippocampal network rapidly encoded each scene as it was experienced. It then replayed the scenes over and over again to train the generative neural network in the neocortex.

The neocortical network learned to pass the activity of the thousands of input neurons (neurons that receive visual information) representing each scene through smaller intermediate layers of neurons (the smallest containing only 20 neurons), to recreate the scenes as patterns of activity in its thousands of output neurons (neurons that predict the visual information).

This caused the neocortical network to learn highly efficient “conceptual” representations of the scenes that capture their meaning (e.g. the arrangements of walls and objects) – allowing both the recreation of old scenes and the generation of completely new ones.

Consequently, the hippocampus was able to encode the meaning of new scenes presented to it, rather than having to encode every single detail, enabling it to focus resources on encoding unique features that the neocortex couldn’t reproduce – such as new types of objects.

The model explains how the neocortex slowly acquires conceptual knowledge and how, together with the hippocampus, this allows us to “re-experience” events by reconstructing them in our minds.

The model also explains how new events can be generated during imagination and planning for the future, and why existing memories often contain “gist-like” distortions – in which unique features are generalised and remembered as more like the features in previous events.

Senior author, Professor Neil Burgess (UCL Institute of Cognitive Neuroscience and UCL Queen Square Institute of Neurology), explained: “The way that memories are re-constructed, rather than being veridical records of the past, shows us how the meaning or gist of an experience is recombined with unique details, and how this can result in biases in how we remember things.”

https://neurosciencenews.com/ai-imagination-memory-25498/

Brain Activity Now Watchable and Listenable

·February 21, 2024

Summary: Researchers developed an innovated a technique to convert complex neuroimaging data into audiovisual formats. By transforming brain activity and blood flow data from behaviors like running or grooming in mice into synchronized piano and violin sounds, accompanied by video, they offer an intuitive approach to explore the brain’s intricate workings.

This method not only makes it easier to identify patterns in large datasets but also enhances the understanding of the dynamic relationship between neuronal activity and behavior. The toolkit represents a significant step forward in neuroscientific research, enabling scientists to intuitively screen and interpret vast amounts of brain data.

Key Facts:

1. Audiovisual Data Conversion: The toolkit translates neuroimaging data into a combination of musical notes and video, with different instruments representing various types of brain activity.

2. Enhanced Pattern Recognition: This approach allows researchers to more easily identify correlations between specific brain activities and behaviors, enriching the analysis of complex neuroimaging datasets.

3. Applications Across Experiments: Demonstrated across different experimental settings, including 2D and 3D brain imaging techniques, this method provides a versatile tool for neuroscientific exploration.

Source: PLOS

Complex neuroimaging data can be explored through translation into an audiovisual format – a video with accompanying musical soundtrack – to help interpret what happens in the brain when performing certain behaviors.

David Thibodeaux and colleagues at Columbia University, US, present this technique in the open-access journal PLOS ONE on February 21, 2024. Examples of these beautiful “brain movies” are included below.

Recent technological advances have made it possible for multiple components of activity in the awake brain to be recorded in real time. Scientists can now observe, for instance, what happens in a mouse’s brain when it performs specific behaviors or receives a certain stimulus.

However, such research produces large quantities of data that can be difficult to intuitively explore to gain insights into the biological mechanisms behind brain activity patterns.

Prior research has shown that some brain imaging data can be translated into audible representations. Building on such approaches, Thibodeaux and colleagues developed a flexible toolkit that enables translation of different types of brain imaging data—and accompanying video recordings of lab animal behavior—into audiovisual representations.

The researchers then demonstrated the new technique in three different experimental settings, showing how audiovisual representations can be prepared with data from various brain imaging approaches, including 2D wide-field optical mapping (WFOM) and 3D swept confocally aligned planar excitation (SCAPE) microscopy.

The toolkit was applied to previously-collected WFOM data that detected both neural activity and brain blood flow changes in mice engaging in different behaviors, such as running or grooming.

Neuronal data was represented by piano sounds that struck in time with spikes in brain activity, with the volume of each note indicating magnitude of activity and its pitch indicating the location in the brain where the activity occurred. Meanwhile, blood flow data were represented by violin sounds.

The piano and violin sounds, played in real time, demonstrate the coupled relationship between neuronal activity and blood flow. Viewed alongside a video of the mouse, a viewer can discern which patterns of brain activity corresponded to different behaviors.

The authors note that their toolkit is not a substitute for quantitative analysis of neuroimaging data. Nonetheless, it could help scientists screen large datasets for patterns that might otherwise have gone unnoticed and are worth further analysis.

The authors add: “Listening to and seeing representations of [brain activity] data is an immersive experience that can tap into this capacity of ours to recognize and interpret patterns (consider the online security feature that asks you to “select traffic lights in this image” – a challenge beyond most computers, but trivial for our brains)…[It] is almost impossible to watch and focus on both the time-varying [brain activity] data and the behavior video at the same time, our eyes will need to flick back and forth to see things that happen together.

“You generally need to continually replay clips over and over to be able to figure out what happened at a particular moment. Having an auditory representation of the data makes it much simpler to see (and hear) when things happen at the exact same time.”

https://neurosciencenews.com/brain-activity-audiovisual-25640/

Mapping Love and Sex in the Brain

Summary: Researchers developed the first comprehensive brain map showing activity in prairie voles during mating and bonding, uncovering 68 brain regions involved in forming enduring monogamous relationships. This study challenges previous assumptions that male and female brains operate differently during these processes, revealing nearly identical patterns of brain activity in both sexes.

Surprisingly, the most significant predictor of bonding-related brain activity was found to be male ejaculation, suggesting a profound emotional state that facilitates pair bonding. This groundbreaking research not only offers insights into the neurobiological basis of monogamy but also hints at potential parallels in human relationship formation and maintenance.

Key Facts:

1. Comprehensive Brain Activity Mapping: The study identified 68 distinct brain regions involved in the stages of mating, bonding, and the development of stable relationships in prairie voles.

2. Gender Similarities in Brain Patterns: Contrary to previous beliefs, the research found nearly identical patterns of brain activity in both male and female voles during bonding processes.

3. Emotional State Tied to Male Ejaculation: The strongest predictor of bonding-related brain activity was male ejaculation, indicating its significant role in facilitating pair bonding and potentially suggesting orgasm-like responses in both sexes.

Source: UT Austin

How does sex relate to lasting love?

To answer that question, scientists have long studied a small Midwestern rodent called the prairie vole, one of the few mammals known to form long-term, monogamous relationships.

A team of researchers including Steven Phelps at The University of Texas at Austin has created the first brain-wide map of regions that are active in prairie voles during mating and pair bonding.

The researchers found that bonding voles experience a storm of brain activity distributed across 68 distinct brain regions that make up seven brain-wide circuits. The brain activity correlates with three stages of behavior: mating, bonding and the emergence of a stable, enduring bond.

Most of these brain regions the researchers identified were not previously associated with bonding, so the map reveals new places to look in the human brain to understand how we form and maintain close relationships.

Earlier studies concluded that male and female brains often use fundamentally different mechanisms to produce the same behaviors, such as mating and nurturing offspring. But in this study, bonding males and females had nearly identical patterns of brain activity.

“That was a surprise,” said Phelps, a professor of integrative biology at UT Austin and senior author of the new study in the journal eLife.

“Sex hormones like testosterone, estrogen and progesterone are important for sexual, aggressive and parental behaviors, so the prevailing hypothesis was that brain activity during mating and bonding would also be different between the sexes.”

Compared with humans, prairie voles have whirlwind courtships. Within half an hour of being together, a male and female begin to have sex, and they will do so repeatedly, often many times an hour.

Within a day, their amorousness will lead the pair to form a bond that can last a lifetime. Bonded pairs will groom each other, console each other when stressed, defend their shared territory and rear their young together.

The researchers were able to pinpoint with high resolution which brain cells were active in vole brains at various points over the course of the process that leads to and includes bonding.

This is the first time such a method has been applied to prairie voles. By studying more than 200 prairie voles across multiple times during mating and bonding, the researchers produced an unprecedented and foundational data set.

The strongest predictor of activity across the 68 brain regions that the researchers identified surprised them. It was male ejaculation, suggesting the experience elicits a profound emotional state—and not only in the affected males. Females, too, had more bonding-related brain activity with males who reached that milestone.

“The brain and behavior data suggest that both sexes may be having orgasm-like responses, and these ‘orgasms’ coordinate the formation of a bond,” Phelps said. “If true, it would imply that orgasms can serve as a means to promote connection, as has long been suggested in humans.”

Phelps cautioned that it’s impossible to know whether a female prairie vole is having an orgasm simply by watching its sexual behavior, though previous research has found that some female animals such as monkeys have these physiological responses.

In addition to Phelps, the study’s co-authors are Morgan Gustison, a former postdoctoral researcher at UT Austin now at the University of Western Ontario, Rodrigo Muñoz-Castañeda at Weill Cornell Medicine, and Pavel Osten at Cold Spring Harbor Laboratory.

Funding: The National Institutes of Health funded the research.

https://neurosciencenews.com/intimacy-brain-mapping-25649/

Smiling Alters Emotional Perceptions

https://neurosciencenews.com/genes-nutrition-neurodevelopment-25635/

·February 21, 2024

Summary: Researchers discovered that a brief, electrically induced smile can make neutral faces seem happier, a revelation that holds promise for understanding emotional perception and potentially treating affective disorders. The study utilized facial electrical stimulation, a technique inspired by Charles Darwin’s work, to produce quick, involuntary smiles in participants.

This novel approach demonstrated that even a fleeting smile could significantly alter emotional perception, marking the first evidence of its kind. With implications for theoretical debates and clinical applications, this research could pave the way for new treatments for conditions like depression, Parkinson’s, and autism by enhancing facial emotion recognition.

Key Facts:

1. Innovative Experimentation: Utilizing electrical stimulation, the study is the first to show that activating smile muscles makes neutral faces appear more joyful.

2. Historical Inspiration: The technique modernizes methods developed by Duchenne de Boulogne and featured by Charles Darwin, applying controlled electrical currents to induce smiles with precision.

3. Potential Clinical Applications: The findings open new avenues for exploring treatments for mood disorders and conditions affecting emotional expression, like Parkinson’s and autism, through improved understanding of facial feedback in emotion perception.

Source: University of Essex

Smiling for just a split second makes people more likely to see happiness in expressionless faces, new University of Essex research has revealed.

The study led by Dr Sebastian Korb, from the Department of Psychology, shows that even a brief weak grin makes faces appear more joyful.

The pioneering experiment used electrical stimulation to spark smiles and was inspired by photographs made famous by Charles Darwin.

A painless current manipulated muscles momentarily into action – creating a short uncontrollable smile.

This is the first time facial electrical stimulation has been shown to affect emotional perception.

Dr Korb hopes the research can explore potential treatments for depression or disorders that affect expression, like Parkinson’s and autism.

He said: “The finding that a controlled, brief and weak activation of facial muscles can literally create the illusion of happiness in an otherwise neutral or even slightly sad looking face, is ground-breaking.

“It is relevant for theoretical debates about the role of facial feedback in emotion perception and has potential for future clinical applications.”

Dr Korb used a modernised version of a technique first developed in the 19th century by the French physician Duchenne de Boulogne.

Darwin published drawings of Duchenne’s work in The Expression of the Emotions in Man and Animals – his third major work on evolution.

However, the voltage was dialled down for the new experiments to ensure the safety of participants and better control the smiles.

By using computers, the team were able to control the onset of smiles with millisecond precision.

In total 47 people took part in the Essex study which was published in Social Cognitive and Affective Neuroscience.

They were shown digital avatars and asked to assess whether they looked happy or sad. In half the trials, smiling muscles were activated at the onset of the face.

It emerged that producing a weak smile for 500 milliseconds was enough to induce the perception of happiness.

Dr Korb says the results help us understand facial feedback and he hopes to expand the study.

He said: “We are currently conducting more al research to further explore the phenomenon in healthy participants.

“In the future, however, we hope to apply this technique to explore facial emotion recognition, for people with conditions like Parkinson’s, who are known to have reduced spontaneous facial mimicry and impaired facial emotion recognition.

“Moreover, we have published guidelines to allow other researchers to safely start using electrical facial muscle stimulation.”

https://neurosciencenews.com/smiling-emotional-perception-25643/

Genes and Nutrition Shape Baby Brain Growth

FeaturedGeneticsNeuroscience·February 20, 2024

Summary: Researchers uncovered how both maternal and fetal genes, alongside nutritional factors, influence the development of a baby’s cerebral cortex. Their research, leveraging the UK Biobank’s extensive data, found a direct association between higher birth weight, influenced by specific genetic variants, and increased cortical surface area.

The study highlights the significant roles of fetal insulin-related genes and maternal genes aiding toxin elimination in brain growth. Intriguingly, exposure to nutritional stresses like wartime famine showed a generational impact, emphasizing the critical interplay between genetics and environmental factors in prenatal and early life brain development.

Key Facts:

Genetic and Nutritional Influences: Genetic variants in both the mother and baby that contribute to birth weight are closely linked to the growth of the cerebral cortex, with maternal and fetal genes playing distinct roles.

Impact of Food Availability: The study demonstrates that the availability of food can modulate the influence of these genetic variants on brain development, with maternal detoxification genes being more crucial during times of famine.

Generational Effects: Exposure to extreme conditions such as the Dutch winter famine of 1944-45 highlighted the enduring impact of maternal genes on offspring’s cortical development, suggesting a transgenerational transmission of adaptive traits.

Source: University of Montreal

A new population-based study led by CHU Sainte-Justine researcher and Université de Montréal medical professor Tomas Paus reveals the roles of maternal and fetal genes in the growth of a baby’s cerebral cortex.

Published last week in Nature Communications, the study shows that genetic variants associated with higher birth weight are also associated with greater growth of the cerebral cortex.

However, food abundance or scarcity seems to influence the extent of the role played by the genes of the mother and the unborn baby.

With postdoctoral fellow Daniel Vosberg, Paus analyzed birth weight, birthweight genes and brain magnetic resonance imaging (MRI) data from several thousand adults in the UK Biobank, a biomedical database in the United Kingdom.

These analyses confirmed that higher birth weight is associated with larger cortex size (measured by surface area). In addition, the genetic variants present in the mother and baby that are associated with birthweight are also associated with cortical surface. In the baby, genes associated with insulin action are decisive, while in the mother, genetic variants favoring toxin elimination at the cellular level play a major role.

The two groups of genetic variants are not always equally important in determining cortex size.

“By comparing data by birth year and using statistical modeling and cellular interaction analysis, we’ve demonstrated the role of exposure to food restriction during gestation or infancy,” said Paus.

Exposed to wartime famine

In those who were exposed to wartime famine during the “Dutch winter” of 1944–45, maternal detoxification genes had the greatest impact on cortical growth.

This trait seems to be transmitted from one generation to the next, since the association is also found in the children of people who were thus exposed. In others, cortical growth is mainly associated with genes associated with fetal insulin action.

The analyses suggest that the genes that counteract the negative effects of food restriction, particularly in terms of cellular stress and immune activation, are critical.

“In times of famine, when cells are multiplying, the risk of errors is much greater,” said Paus. “That could explain why, in this context, the genes responsible for DNA repair are decisive for the baby’s brain growth.”

With a better understanding of the relationship between low birth weight and brain growth, and the importance of malnourishment as a mediating factor, the researchers will next evaluate the best way to promote cortical growth after birth in small babies.

In collaboration with CHU Sainte-Justine pediatrician and UdeM clinical associate professor Thuy Mai Luu, “we’ll soon be launching a pilot project to determine the best way to support optimal brain development in low-birth-weight babies,” said Paus.

Decision Making: The Brain’s Blueprint for Future Insights

FeaturedNeuroscience·February 20, 2024

Summary: Researchers made a breakthrough in understanding how the brain makes decisions about future information, pinpointing the lateral habenula as a key player in this process. Their study demonstrates that humans and animals evaluate the worth of cognitive rewards, such as information about the future, using mental rules that the brain applies to both tangible rewards and the intangible satisfaction of curiosity.

This research not only sheds light on the fundamental mechanisms of decision-making but also offers potential pathways for treating mental health disorders characterized by impaired decision-making, such as OCD, anxiety, and depression, by targeting specific neural circuits involved in processing uncertainty and cognitive rewards.

Key Facts:

Lateral Habenula’s Role: The study identifies the lateral habenula, an ancient brain structure, as crucial in regulating decision-making about physical and cognitive rewards.

Mental Rules for Decision-Making: Researchers discovered that the brain uses a set of mental rules to decide the value of information about the future, revealing how much individuals are willing to pay to resolve uncertainty.

Implications for Mental Health: The findings have significant implications for understanding and treating mental illnesses that affect decision-making, pointing towards more personalized medicine approaches by pinpointing specific malfunctions in uncertainty processing.

Source: WUSTL

Researchers at Washington University School of Medicine in St. Louis have new insight on what goes on inside people’s heads as they make decisions to obtain information about the future.

The scientists identified a set of mental rules that governs decision-making about physical rewards—for example, food or money—and cognitive rewards—like the joy felt when accessing sought information.

They also identified the part of the brain that regulates this type of decision-making. The process occurs in the lateral habenula, an ancient brain structure shared by species as distantly related as people and fish.

The study is published in Nature Neuroscience.

The findings not only offer insight into the body’s most mysterious organ but have the potential to help people struggling with tough choices, whether due to the inherent complexity of certain decisions—such as whether to take a genetic test that might return unwelcome information—or due to mental illnesses that affect the ability to make decisions, such as obsessive-compulsive disorder (OCD), anxiety and depression.

“Identifying the circuits involved with assigning value to cognitive rewards, like information about the future, is really important, because that kind of valuation is often what breaks down in mental disorders,” said senior author Ilya Monosov, a professor of neuroscience at Washington University.

“If we can understand exactly what part of the decision-making process is malfunctioning in an individual, we may be able to target that aspect of the process precisely and treat some mental illnesses more effectively.”

Making a choice between two options often requires weighing the values of and making trade-offs between multiple factors. Some of these factors are concrete and practical. But there are also intangible factors that can provide powerful motivation to choose one option over another, such as the desire to satisfy curiosity and gain information.

Some information has practical value, of course, such as advance warning of an incoming hurricane. But experiments have shown that people and animals value obtaining information even when they cannot parlay it into something useful.

“Take, for example, a student who turns in a final exam and then wants to know the results immediately,” said co-first author Yang-Yang Feng, an MD/Ph.D. student who designed and led the the study’s experiments with human participants.

“Finding out your score today versus finding out in a week won’t change the results or gain you any kind of advantage. But some people want to know so badly that they will pay to find out early. That’s called non-instrumental information seeking, trying to obtain information for its own sake.”

Historically, the drive to obtain practical rewards, such as money or food, and the drive to obtain information have been studied as separate phenomena. This division is artificial and oversimplifies the choices people make in the real world, the researchers said.

Feng and co-first author Ethan Bromberg-Martin, a senior scientist in Monosov’s lab, designed experiments that required participants to make trade-offs between rewards and non-instrumental information, to come to a final decision.

Study participants were given a choice between two options, each of which gave them a chance at obtaining a few cents. The amount of money they could win and the likelihood of winning it varied. Some of the options came with the promise to learn the outcome early, before actual money arrived. In separate experiments, monkeys were offered analogous choices, with juice as the reward instead of money.

“By analyzing the trade-offs individuals made, we were able to work out some of the rules that individuals use to decide how much they’re willing to pay for information,” Bromberg-Martin said. “These rules generalized between humans and animals, suggesting that this abstract value may be conserved through evolution.”

One of the key principles they uncovered is that individuals seek information largely to resolve uncertainty. The more uncertainty, the more they are willing to pay for information about it. Intuitively, this makes sense.

You would probably be willing to pay more to find out the outcome of a $100 bet than a $1 bet, especially if you could get the information sooner rather than later. These and other principles form a logical framework that the brain relies on to make choices.

But sometimes the system malfunctions.

“Some people with OCD exhibit what’s known as checking behaviors, where they go back and check the same thing over and over,” Monosov said. “This is aberrant information-seeking behavior, and it is basically due to a misprocessing of uncertainty.”

As part of this study, the team discovered that decision-making algorithms are implemented through a neurological circuit that culminates in the lateral habenula, a tiny structure located deep in the brain. The lateral habenula is a major regulator of dopamine and has been linked to mental illnesses including depression, anxiety and OCD.

The team is working on using tasks requiring participants to make choices, similar to those in this study, to classify people with OCD into subtypes that correspond to how their brains process uncertainty. Doing so would be a step toward more targeted therapies.

“A person may be fine in some regards, but their uncertainty processing is off in one specific way,” Monosov said.

“Rather than saying that someone has a broad mental disorder such as OCD, we could say that their uncertainty processing is broken in this specific way, and here’s how we can modulate it. It’s a step toward more personalized medicine for mental illnesses.”

https://neurosciencenews.com/decision-making-brain-insight-25637/

Ripples of Recall: Brain Waves Play Key Role in Memory

Summary: Researchers have advanced our understanding of the neuronal basis of spatial memory. Their research reveals that during spatial memory tasks, different types of nerve cells activate in unison, coordinated by brain waves known as “ripples.”

This discovery highlights the intricate process of how our brains link locations to objects, a fundamental aspect of associative memory that can deteriorate in conditions like Alzheimer’s disease. The findings not only deepen our comprehension of human memory but also pave the way for potential new treatments for memory impairments.

Key Facts:

Diverse Neuronal Activation: The study found that specific nerve cells respond to objects and locations during memory retrieval, working together to form associative memories.

Role of Brain Waves: Hippocampal ripples were observed to play a crucial role in coordinating these nerve cells, suggesting their importance in memory formation and retrieval.

Potential for Future Therapies: Understanding the neuronal basis of spatial and associative memory could lead to new therapeutic approaches for treating memory disorders such as Alzheimer’s.

Source: University of Bonn

Spatial navigation and spatial memory play a central role in our lives. Without these abilities, we would hardly be able to find our way around our surroundings and would find it difficult to remember past events. However, the neuronal basis of spatial memory is far from being fully understood.

A research group led by Prof. Lukas Kunz, who has recently joined the University Hospital Bonn (UKB), has gained new insights into this gap in knowledge. Together with scientists from New York and Freiburg, he discovered that different types of nerve cells become active together during spatial memory and are coordinated by brain waves (“ripples”).

The results have now been published in the journal Nature Neuroscience.

Associative memory allows that different pieces of information are linked together. “In the context of spatial memory, associative memory enables us to remember the locations of certain objects in the spatial environment,” explains Prof. Kunz, research group leader for Cognitive and Translational Neuroscience at the Department of Epileptology at the UKB. He is also a member of the Transdisciplinary Research Area (TRA) “Life & Health” at the University of Bonn.

“For example, we can remember where in the house we put our keys”. At older age or in certain diseases such as Alzheimer’s, however, this ability is limited.

“It is therefore important to investigate the neuronal basis of different forms of human memory,” says Prof. Kunz. In the long term, this could help develop new therapies for memory impairments.

Nerve cells play an important role in associative memory

Nerve cells are active while information is retrieved from memory. To further investigate this phenomenon, the researchers recorded the activity of individual nerve cells in epilepsy patients performing a memory task.

“In a virtual world, the participants were asked to remember the locations of different objects,” explains Prof. Kunz.

The recordings showed that different types of nerve cells became active during this memory task. Some nerve cells responded to certain objects, while other nerve cells activated in response to certain locations. The scientists observed that interactions between the different types of nerve cells became stronger over time when participants remembered the right object in the right place.

Brain waves coordinate the nerve cells

In addition to place and object neurons, the researchers observed hippocampal brain waves (“ripples”) that also occurred during the memory task, presumably playing a crucial role in the formation and retrieval of associative memories.

“Ripples could be important for the connection of different types of nerve cells and the formation of complex memories. It will be exciting to further investigate this idea in future studies,” explains Prof. Kunz.

It will also be interesting to study how memory performance is modulated when ripples are suppressed or triggered, providing insights into the causal relevance of ripples.

Prof. Kunz intends to continue the findings that he gained with his colleagues at Columbia University’s School of Engineering and Applied Science in New York and the University of Freiburg at the University Hospital Bonn.

“The department of epileptology at the UKB is well-known for its excellent brain research. The department has the unique opportunity to record the activity of individual nerve cells in the human brain in the video EEG monitoring unit, which is the heart of every epilepsy center.

“This provides exciting insights into the functioning of the human brain, which is only possible at a few research centers worldwide,” describes Prof. Kunz.

In his interdisciplinary research, he builds on the close exchange with other researchers and medical doctors, which is essential for the development of new research ideas.

https://neurosciencenews.com/memory-brain-waves-25630/

Why We Learn Better From People We Like

Summary: Our brains favor learning from individuals we like over those we dislike, a phenomenon crucial for memory integration.

Through experiments involving everyday objects, the study demonstrated that our ability to connect information and form new inferences is significantly affected by our personal feelings towards the information provider. This selective memory integration can shape our perceptions and beliefs, even in neutral contexts, suggesting an innate bias in how we assimilate information.

The findings highlight the fundamental role of personal preferences in learning and the potential for reinforcing polarization in society.

Key Facts:

1. Our brains preferentially learn from and integrate information presented by people we like, affecting how we connect new experiences.

2. This bias in memory integration can influence our beliefs and perceptions, potentially leading to selective memory and reinforced polarization.

3. The research provides a fundamental insight into how personal preferences impact learning processes, extending beyond social media filter bubbles to basic brain functions.

Source: Lund University

Our brains are “programmed” to learn more from people we like – and less from those we dislike. This has been shown by researchers in cognitive neuroscience in a series of experiments.

Memory serves a vital function, enabling us to learn from new experiences and update existing knowledge. We learn both from individual experiences and from connecting them to draw new conclusions about the world.

This way, we can make inferences about things that we don’t necessarily have direct experience of. This is called memory integration and makes learning quick and flexible.

Inês Bramão, associate professor of psychology at Lund University, provides an example of memory integration: Say you’re walking in a park. You see a man with a dog. A few hours later, you see the dog in the city with a woman. Your brain quickly makes the connection that the man and woman are a couple even though you have never seen them together.

“Making such inferences is adaptive and helpful. But of course, there’s a risk that our brain draws incorrect conclusions or remembers selectively”, says Inês Bramão.

Important who provides the information

To examine what affects our ability to learn and make inferences, Inês Bramão, along with colleagues Marius Boeltzig and Mikael Johansson, set up experiments where participants were tasked with remembering and connecting different objects. It could be a bowl, ball, spoon, scissors, or other everyday objects. It turned out that memory integration, i.e., the ability to remember and connect information across learning events, was influenced by who presented it.

If it was a person the participant liked, connecting the information was easier compared to when the information came from someone the participant disliked. The participants provided individual definitions of ‘like’ and ‘dislike’ based on aspects such as political views, major, eating habits, favorite sports, hobbies, and music.

Can be translated to politics

The findings can be applied in real life, according to the researchers. Inês Bramão takes a hypothetical example from politics:

“A political party argues for raising taxes to benefit healthcare. Later, you visit a healthcare center and notice improvements have been made. If you sympathize with the party that wanted to improve healthcare through higher taxes, you’re likely to attribute the improvements to the tax increase, even though the improvements might have had a completely different cause”.

About fundamental mechanisms

There’s already vast research describing that people learn information differently depending on the source and how that characterizes polarization and knowledge resistance.

“What our research shows is how these significant phenomena can partly be traced back to fundamental principles that govern how our memory works”, says Mikael Johansson, professor of psychology at Lund University. “

We are more inclined to form new connections and update knowledge from information presented by groups we favor. Such preferred groups typically provide information that aligns with our pre-existing beliefs and ideas, potentially reinforcing polarized viewpoints”.

Innate way of handling information

Understanding the roots of polarization, resistance to new knowledge, and related phenomena from basic brain functions offers a deeper insight into these complex behaviors, the researchers argue. So, it’s not just about filter bubbles on social media but also about an innate way of assimilating information.

“Particularly striking is that we integrate information differently depending on who is saying something, even when the information is completely neutral. In real life, where information often triggers stronger reactions, these effects could be even more prominent”, says Mikael Johansson.

About this learning and memory research news

Author: Lotte Billing
Source: Lund University
Contact: Lotte Billing – Lund University
Image: The image is credited to Neuroscience News

Original Research: Open access.
“Ingroup sources enhance associative inference” by Ines Bramao et al. Communications Psychology

Abstract

Ingroup sources enhance associative inference

Episodic memory encompasses flexible processes that enable us to create and update knowledge by making novel inferences across overlapping but distinct events. Here we examined whether an ingroup source enhances the capacity to draw such inferences.

In three studies with US-American samples (N_Study1 = 53, N_Study2 = 68, N_Study3 = 68), we investigated the ability to make indirect associations, inferable from overlapping events, presented by ingroup or outgroup sources.

Participants were better at making inferences based on events presented by ingroup compared to outgroup sources (Studies 1 and 3). When the sources did not form a team, the effect was not replicated (Study 2). Furthermore, we show that this ingroup advantage may be linked to differing source monitoring resources allocated to ingroup and outgroup sources.

Altogether, our findings demonstrate that inferential processes are facilitated for ingroup information, potentially contributing to spreading biased information from ingroup sources into expanding knowledge networks, ultimately maintaining and strengthening polarized beliefs.

The Impact of Borderline Personality Disorder on Jealousy and Relationship Retention

Featured Genetics Neuroscience

·February 15, 2024

Summary: Individuals with borderline personality (BPD) features are more prone to suspicious jealousy, which significantly influences their romantic relationships. This suspiciousness leads to a range of mate retention behaviors, from affection and support to criticism and abuse.

The study highlights the complex role of BPD traits in shaping how individuals navigate romantic engagements, emphasizing the critical influence of emotional regulation on relationship dynamics. It underlines the need for a deeper understanding of BPD features’ impact on interpersonal relationships, offering insights into both the positive and negative strategies employed for mate retention.

Key Facts:

1. Individuals with BPD traits exhibit higher levels of suspicious jealousy, affecting their approach to mate retention.

2. This jealousy leads to both positive (benefit-provisioning) and negative (cost-inflicting) behaviors in relationships.

3. The study’s findings are based on self-reported data and online samples, pointing to the intricate link between BPD features and relationship dynamics.

Source: Neuroscience News

Virgil Zeigler-Hill and Jennifer Vonk’s recent publication in Sexes unveils the intricate dynamics of how borderline personality features influence romantic relationships, with a keen focus on the mechanisms of suspicious jealousy.

This study brings to light that individuals with pronounced features associated with Borderline Personality Disorder (BPD) navigate romantic engagements through a broad spectrum of behaviors aimed at keeping their partners close.

From exhibiting affection and support to engaging in more detrimental actions such as criticism, neglect, or abuse, the behaviors are deeply intertwined with feelings of suspicious jealousy.

BPD is characterized by significant instability in interpersonal relationships, self-image, and emotions, alongside marked impulsivity. The disorder typically manifests in early adulthood across various contexts.

Individuals may experience intense episodes of anger, depression, and anxiety, which can last from a few hours to days. Zeigler-Hill and Vonk extend these findings to include individuals who exhibit borderline personality features but might not meet the full criteria for BPD diagnosis.

These individuals still show tendencies towards emotional dysregulation, fear of abandonment, frequent mood swings, and difficulty controlling anger, which in turn affects their romantic relationships.

In their study, the authors categorize mate retention strategies into two main types: benefit-provisioning and cost-inflicting behaviors.

Benefit-provisioning behaviors aim to positively affect the partner’s well-being through expressions of affection and support. On the other hand, cost-inflicting behaviors have a negative impact, including criticism, neglect, dishonesty, or abuse.

The study’s findings underscore that suspicious jealousy, characterized by doubts about a partner’s fidelity without solid evidence, often arising from personal insecurities or fears, is a significant driver of both types of behaviors in individuals with borderline personality features.

The researchers report that participants with higher levels of borderline personality features demonstrated a greater propensity for suspicious jealousy. This form of jealousy, in turn, increased their likelihood of engaging in both benefit-provisioning behaviors, such as showing affection and support, and cost-inflicting behaviors.

Notably, the study highlights that while benefit-provisioning behaviors can strengthen the bond between partners by fostering trust and intimacy, cost-inflicting behaviors, particularly those involving criticism, neglect, and abuse, can undermine trust, reduce relationship satisfaction, and potentially lead to the relationship’s demise.

Statistically, the study points out a significant correlation between borderline personality features and the increased use of mate retention strategies, both positive and negative. Specifically, individuals with higher borderline personality features were more likely to engage in cost-inflicting behaviors as a means of mate retention, showcasing the complex interplay between emotional dysregulation, fear of abandonment, and relationship dynamics.

This research provides a nuanced understanding of how borderline personality features can shape the landscape of romantic relationships, highlighting the dual nature of suspicious jealousy in promoting behaviors aimed at mate retention.

While the study offers profound insights, it also acknowledges its reliance on self-reported data and online samples, suggesting a need for further investigation through observational studies to validate and expand upon these findings.

By shedding light on the complex relationship between borderline personality features, suspicious jealousy, and mate retention behaviors, Zeigler-Hill and Vonk’s study opens new avenues for understanding and addressing the challenges faced by individuals with these personality features in romantic relationships.

About this mental health, BPD, and relationships research news

Author: Neuroscience News Communications
Source: Neuroscience News
Contact: Neuroscience News Communications – Neuroscience News
Image: The image is credited to Neuroscience News

Original Research: Open access.
“Borderline Personality Features and Mate Retention Behaviors: The Mediating Roles of Suspicious and Reactive Jealousy” by Virgil Zeigler-Hill et al. Sexes

Abstract

Borderline Personality Features and Mate Retention Behaviors: The Mediating Roles of Suspicious and Reactive Jealousy

We investigated the roles that suspicious jealousy and reactive jealousy might play in the associations between borderline personality features (BPF) and mate retention behaviors.

Study 1 (N = 406) found that BPF had positive indirect associations with benefit-provisioning behaviors and cost-inflicting behaviors through suspicious jealousy but not through reactive jealousy.

Study 2 (N = 334 (a dyadic sample of 167 romantic couples)) revealed actor effects such that BPF had positive indirect associations with benefit-provisioning behaviors and cost-inflicting behaviors through suspicious jealousy for both men and women.

In addition, the positive association between BPF and benefit-provisioning behaviors was mediated by reactive jealousy in women but not in men.

The only partner effect that emerged from these analyses showed that BPF in women were negatively associated with the benefit-provisioning behaviors reported by their male partners.

Discussion focuses on the implications of these results for the function that jealousy might serve in the strategies used by individuals with BPF to maintain their romantic relationships.

Unlocking Cell Death Secrets: Lipids Key to Ferroptosis Control

·February 15, 2024

Summary: Researchers have made a groundbreaking discovery, identifying a rare lipid as a crucial factor in ferroptosis, a unique form of cell death. This lipid, characterized by its two polyunsaturated fatty acyl tails, plays a significant role in various conditions, including neurodegenerative diseases and cancer. The findings could revolutionize our approach to treating these diseases by either preventing or inducing ferroptosis.

Key Facts:

1. Discovery of diPUFA Lipids: A rare lipid with two polyunsaturated fatty acyl tails, known as diPUFA phospholipid, has been found to significantly promote ferroptosis in cells, including those in aging brains and Huntington disease-affected brain tissue.

2. Potential for Disease Treatment: Understanding the role of diPUFA lipids in ferroptosis opens new avenues for treating neurodegenerative diseases and cancer, by either preventing or inducing cell death.

3. Interdisciplinary Research: The research was a collaborative effort by Columbia’s Department of Biological Sciences, Department of Chemistry, and the Columbia University Irving Medical Center, highlighting the interdisciplinary approach to uncovering the mechanisms of ferroptosis.

Source: Columbia University

Columbia researchers have found that a rare type of lipid is a key driver of ferroptosis, a form of cell death discovered by Columbia professor Brent Stockwell.

The findings provide new detail on how cells die during ferroptosis and could improve understanding of how to stop ferroptosis in contexts where it is harmfully occurring– in neurodegenerative diseases, for example– or induce it in contexts where it could be useful, such as using it to kill dangerous cancer cells.

The new research found that a rare type of lipid with two polyunsaturated fatty acyl tails, called a diPUFA phospholipid, was present in a range of contexts where ferroptosis was occurring, including in aging brains and Huntington disease-affected brain tissue. The finding indicates that the lipid is efficient at promoting ferroptosis.

The research was conducted by professors in Columbia’s Department of Biological Sciences, Department of Chemistry, and the Columbia University Irving Medical Center.

Stockwell first discovered ferroptosis in 2012, when he found that certain cells were dying because their lipid layers were collapsing– an unusual form of cell death that differs from the most common kind, which begins with the cell forming blisters on its outer surface.

Since that discovery, researchers in Stockwell’s lab and elsewhere have continued to investigate ferroptosis, discovering that it can occur naturally in aging cells, in pathological contexts, and can be induced to treat disease.

Another paper out this month with several co-authors found that a gene named PHLDA2 can sometimes promote ferroptosis by attacking a different lipid, and that this gene can block some tumors from forming.

Together, these papers show that specific lipids promote ferroptosis, so defining the driver lipids in specific cancers is important.

“The discovery that these diPUFA lipids are important drivers of ferroptosis deepens our understanding of this form of cell death, and these lipids’ role in controlling a cell’s homeostasis in general,” Stockwell said.

“Harnessing these lipids may eventually help us identify where ferroptosis has occurred and deliberately manipulate them to either induce cell death or stop it. This can begin to give us both understanding and the power to control cell death.”

https://neurosciencenews.com/ferroptosis-lipids-25622/

Persistent Impact of Smoking on the Immune System

·February 14, 2024

Summary: Smoking not only affects immune responses in the short term but also leaves a lasting imprint on the body’s defense mechanisms. Through the Milieu Intérieur cohort of 1,000 healthy volunteers, the study identified smoking, alongside latent cytomegalovirus infection and body mass index, as a key factor influencing immune responses.

This groundbreaking research demonstrates that the effects of smoking on adaptive immunity can persist for 10 to 15 years after cessation, attributed to epigenetic changes in DNA methylation that alter gene expression involved in immune cell metabolism. This insight opens new avenues for understanding how lifestyle choices like smoking can have enduring effects on our health.

Key Facts:

1. Smoking significantly impacts both innate and adaptive immune responses, with some effects persisting for up to 15 years after quitting.

2. The study used the Milieu Intérieur cohort to demonstrate how smoking, latent cytomegalovirus infection, and body mass index are major factors affecting immunity.

3. Long-term effects of smoking on immunity are linked to epigenetic changes, specifically DNA methylation, highlighting the durable influence of smoking on the body’s defense systems.

Source: Institut Pasteur

Like other factors such as age, sex and genetics, smoking has a major impact on immune responses.

This is the finding recently made by a team of scientists at the Institut Pasteur using the Milieu Intérieur cohort of 1,000 healthy volunteers, established to understand variability in immune responses.

In addition to its short-term impact on immunity, smoking also has long-term consequences. For many years after they have quit the habit, smokers are left with effects on some of their bodies’ defense mechanisms acquired while smoking.

Basically, the immune system appears to have something resembling a long-term memory of the effects of smoking. Credit: Neuroscience News

These findings, which for the first time reveal a long-term memory of the effects of smoking on immunity, will be published in the journal Nature on February 14, 2024.

Individuals’ immune systems vary significantly in terms of how effectively they respond to microbial attacks. But how can this variability be explained? What factors cause these differences?

“To answer this key question, we set up the Milieu Intérieur cohort comprising 1,000 healthy individuals aged 20 to 70 in 2011,” comments Darragh Duffy, Head of the Translational Immunology Unit at the Institut Pasteur and last author of the study.

While certain factors such as age, sex and genetics are known to have a significant impact on the immune system, the aim of this new study was to identify which other factors had the most influence.”

The scientists exposed blood samples taken from individuals in the Milieu Intérieur cohort to a wide variety of microbes (viruses, bacteria, etc.) and observed their immune response by measuring levels of secreted cytokines.

Using the large quantities of data gathered for individuals in the cohort, the team then determined which of the 136 investigated variables (body mass index, smoking, number of hours’ sleep, exercise, childhood illnesses, vaccinations, living environment, etc.) had the most influence on the immune responses studied.

Three variables stood out: smoking, latent cytomegalovirus infection and body mass index. “The influence of these three factors on certain immune responses could be equal to that of age, sex or genetics,” points out Darragh Duffy.

As regards smoking, an analysis of the data showed that the inflammatory response, which is immediately triggered by infection with a pathogen, was heightened in smokers, and moreover, the activity of certain cells involved in immune memory was impaired. In other words, this study shows that smoking disrupts not only innate immune mechanisms, but also some adaptive immune mechanisms.

“A comparison of immune responses in smokers and ex-smokers revealed that the inflammatory response returned to normal levels quickly after smoking cessation, while the impact on adaptive immunity persisted for 10 to 15 years,” observes Darragh Duffy.

“This is the first time it has been possible to demonstrate the long-term influence of smoking on immune responses.”

Basically, the immune system appears to have something resembling a long-term memory of the effects of smoking. But how?

“When we realized that the profiles of smokers and ex-smokers were similar, we immediately suspected that epigenetic processes were at play,” says Violaine Saint-André, a bioinformatician in the Institut Pasteur’s Translational Immunology Unit and first author of the study.

“We demonstrated that the long-term effects of smoking on immune responses were linked to differences in DNA methylation – with the potential to modify the expression of genes involved in immune cell metabolism – between smokers, ex-smokers and non-smokers.”

It therefore appears that smoking can induce persistent changes to the immune system through epigenetic mechanisms.

“This is a major discovery elucidating the impact of smoking on healthy individuals’ immunity and also, by comparison, on the immunity of individuals suffering from various diseases,” concludes Violaine Saint-André.

About this smoking and immune system research news

Author: Rebeyrotte Myriam
Source: Institut Pasteur
Contact: Rebeyrotte Myriam – Institut Pasteur
Image: The image is credited to Neuroscience News

Original Research: Open access.
“Smoking changes adaptive immunity with persistent effects” by Darragh Duffy et al. Nature

Abstract

Smoking changes adaptive immunity with persistent effects

Individuals differ widely in their immune responses, with age, sex and genetic factors having major roles in this inherent variability. However, the variables that drive such differences in cytokine secretion—a crucial component of the host response to immune challenges—remain poorly defined.

Here we investigated 136 variables and identified smoking, cytomegalovirus latent infection and body mass index as major contributors to variability in cytokine response, with effects of comparable magnitudes with age, sex and genetics.

We find that smoking influences both innate and adaptive immune responses. Notably, its effect on innate responses is quickly lost after smoking cessation and is specifically associated with plasma levels of CEACAM6, whereas its effect on adaptive responses persists long after individuals quit smoking and is associated with epigenetic memory.

This is supported by the association of the past smoking effect on cytokine responses with DNA methylation at specific signal trans-activators and regulators of metabolism.

Our findings identify three novel variables associated with cytokine secretion variability and reveal roles for smoking in the short- and long-term regulation of immune responses. These results have potential clinical implications for the risk of developing infections, cancers or autoimmune diseases. https://neurosciencenews.com/smoking-immune-system-25614/

Brain Network Steering Left and Right Movements Discovered

https://neurosciencenews.com/basal-ganglia-navigation-25596/

·February 12, 2024

Summary: Scientists have identified a new group of neurons that plays a crucial role in controlling left-right movements in walking, bridging a critical gap in our understanding of brainstem and basal ganglia interaction. This discovery provides insights into the brain’s complex navigation system previously linked to the ‘brain’s steering wheel.’

The findings might offer future therapeutic strategies for Parkinson’s disease. By studying mice, the team anticipates similar mechanisms in humans, potentially revolutionizing treatments for movement disorders.

Key Facts:

1. The study reveals a new group of neurons in the brainstem that receives signals from the basal ganglia to control the direction of movement, offering a deeper understanding of how voluntary movements like walking are coordinated.

2. Researchers used optogenetics to modify and stimulate these neurons in mice, successfully correcting impaired left or right movements, showcasing the method’s potential for treating motor symptoms in diseases like Parkinson’s.

3. The basal ganglia’s critical role in voluntary movement has been known, but how it influences left-right movement decisions was unclear until this breakthrough, highlighting the importance of this brain area in motor control.

Source: University of Copenhagen

Have you ever wondered what happens in the brain when we move to the right or left? Most people don’t; they just do it without thinking about it. But this simple movement is actually controlled by a complex process.

In a new study, researchers have discovered the missing piece in the complex nerve-network needed for left-right turns. The discovery was made by a research team consisting of Assistant Professor Jared Cregg, Professor Ole Kiehn, and their colleagues from the Department of Neuroscience at the University of Copenhagen.

In 2020, Ole Kiehn, Jared Cregg and their colleagues identified the ‘brain’s steering wheel’ – a network of neurons in the lower part of the brainstem that commands right- and left- movements when walking. At the time, though, it was not clear to them how this right-left circuit is controlled by other parts of the brain, such as the basal ganglia.

“We have now discovered a new group of neurons in the brainstem which receives information directly from the basal ganglia and control the right-left circuit,” Ole Kiehn explains.

Eventually, this discovery may be able to help people suffering from Parkinson’s disease. The study has been published in the esteemed scientific journal Nature Neuroscience.

The basal ganglia are located deep within the brain. For many years now, they have been known to play a key role in controlling voluntary movements.

Years ago, scientists learned that by stimulating the basal ganglia you can affect right- and left-hand movements in mice. They just did not know how.

“When walking, you will shorten the step length of the right leg before making a right-hand turn and the left leg before making a left-hand turn. The newly discovered network of neurons is located in a part of the brainstem known as PnO. They are the ones that receive signals from the basal ganglia and adjust the step length as we make a turn, and which thus determine whether we move to the right or left,” Jared Cregg explains.

The study therefore provides a key to understanding how these absolutely essential movements are produced by the brain.

In the new study, the researchers studied the brain of mice, as their brainstem closely resembles the human brainstem. Therefore, the researchers expect to find a similar right-left circuit in the human brain.

Can AI Be Controlled?

https://neurosciencenews.com/

·February 12, 2024

Summary: Dr. Roman V. Yampolskiy, an AI Safety expert, warns of the unprecedented risks associated with artificial intelligence in his forthcoming book, AI: Unexplainable, Unpredictable, Uncontrollable. Through an extensive review, Yampolskiy reveals a lack of evidence proving AI can be safely controlled, pointing out the potential for AI to cause existential catastrophes.

He argues that the inherent unpredictability and advanced autonomy of AI systems pose significant challenges to ensuring their safety and alignment with human values. The book emphasizes the urgent need for increased research and development in AI safety measures to mitigate these risks, advocating for a balanced approach that prioritizes human control and understanding.

Key Facts:

1. Dr. Yampolskiy’s review found no concrete evidence that AI can be entirely controlled, suggesting that the development of superintelligent AI could lead to outcomes as dire as human extinction.

2. The complexity and autonomy of AI systems make it difficult to predict their decisions or ensure their actions align with human values, raising concerns over their potential to act in ways that could harm humanity.

3. Yampolskiy proposes that minimizing AI risks requires transparent, understandable, and modifiable systems, alongside increased efforts in AI safety research.

Source: Taylor and Francis Group

There is no current evidence that AI can be controlled safely, according to an extensive review, and without proof that AI can be controlled, it should not be developed, a researcher warns.

Despite the recognition that the problem of AI control may be one of the most important problems facing humanity, it remains poorly understood, poorly defined, and poorly researched, Dr Roman V. Yampolskiy explains.

In his upcoming book, AI: Unexplainable, Unpredictable, Uncontrollable, AI Safety expert Dr Yampolskiy looks at the ways that AI has the potential to dramatically reshape society, not always to our advantage.

He explains: “We are facing an almost guaranteed event with potential to cause an existential catastrophe. No wonder many consider this to be the most important problem humanity has ever faced. The outcome could be prosperity or extinction, and the fate of the universe hangs in the balance.”

Uncontrollable superintelligence

Dr Yampolskiy has carried out an extensive review of AI scientific literature and states he has found no proof that AI can be safely controlled – and even if there are some partial controls, they would not be enough.

He explains: “Why do so many researchers assume that AI control problem is solvable? To the best of our knowledge, there is no evidence for that, no proof. Before embarking on a quest to build a controlled AI, it is important to show that the problem is solvable.

“This, combined with statistics that show the development of AI superintelligence is an almost guaranteed event, show we should be supporting a significant AI safety effort.”

He argues our ability to produce intelligent software far outstrips our ability to control or even verify it. After a comprehensive literature review, he suggests advanced intelligent systems can never be fully controllable and so will always present certain level of risk regardless of benefit they provide. He believes it should be the goal of the AI community to minimize such risk while maximizing potential benefit.

What are the obstacles?

AI (and superintelligence), differ from other programs by its ability to learn new behaviors, adjust its performance and act semi-autonomously in novel situations.

One issue with making AI ‘safe’ is that the possible decisions and failures by a superintelligent being as it becomes more capable is infinite, so there are an infinite number of safety issues. Simply predicting the issues not be possible and mitigating against them in security patches may not be enough.

At the same time, Yampolskiy explains, AI cannot explain what it has decided, and/or we cannot understand the explanation given as humans are not smart enough to understand the concepts implemented. If we do not understand AI’s decisions and we only have a ‘black box’, we cannot understand the problem and reduce likelihood of future accidents.

For example, AI systems are already being tasked with making decisions in healthcare, investing, employment, banking and security, to name a few. Such systems should be able to explain how they arrived at their decisions, particularly to show that they are bias free.

Yampolskiy explains: “If we grow accustomed to accepting AI’s answers without an explanation, essentially treating it as an Oracle system, we would not be able to tell if it begins providing wrong or manipulative answers.”

Controlling the uncontrollable

As capability of AI increases, its autonomy also increases but our control over it decreases, Yampolskiy explains, and increased autonomy is synonymous with decreased safety.

For example, for superintelligence to avoid acquiring inaccurate knowledge and remove all bias from its programmers, it could ignore all such knowledge and rediscover/proof everything from scratch, but that would also remove any pro-human bias.

“Less intelligent agents (people) can’t permanently control more intelligent agents (ASIs). This is not because we may fail to find a safe design for superintelligence in the vast space of all possible designs, it is because no such design is possible, it doesn’t exist. Superintelligence is not rebelling, it is uncontrollable to begin with,” he explains.

“Humanity is facing a choice, do we become like babies, taken care of but not in control or do we reject having a helpful guardian but remain in charge and free.”

He suggests that an equilibrium point could be found at which we sacrifice some capability in return for some control, at the cost of providing system with a certain degree of autonomy.

Aligning human values

One control suggestion is to design a machine which precisely follows human orders, but Yampolskiy points out the potential for conflicting orders, misinterpretation or malicious use.

He explains: “Humans in control can result in contradictory or explicitly malevolent orders, while AI in control means that humans are not.”

If AI acted more as an advisor it could bypass issues with misinterpretation of direct orders and potential for malevolent orders, but the author argues for AI to be useful advisor it must have its own superior values.

“Most AI safety researchers are looking for a way to align future superintelligence to values of humanity. Value-aligned AI will be biased by definition, pro-human bias, good or bad is still a bias. The paradox of value-aligned AI is that a person explicitly ordering an AI system to do something may get a “no” while the system tries to do what the person actually wants. Humanity is either protected or respected, but not both,” he explains.

Minimizing risk

To minimize the risk of AI, he says it needs it to be modifiable with ‘undo’ options, limitable, transparent and easy to understand in human language.

He suggests all AI should be categorised as controllable or uncontrollable, and nothing should be taken off the table and limited moratoriums, and even partial bans on certain types of AI technology should be considered.

Instead of being discouraged, he says: “Rather it is a reason, for more people, to dig deeper and to increase effort, and funding for AI Safety and Security research. We may not ever get to 100% safe AI, but we can make AI safer in proportion to our efforts, which is a lot better than doing nothing. We need to use this opportunity wisely.”

Exploring Brain Scan Hesitancy

MRI brain findings

https://neurosciencenews.com/brain-scan-hesitancy-25590/

·February 9, 2024

Summary: Asian Americans, particularly South and East Asian older adults, exhibit greater hesitancy towards participating in health research involving MRI brain scans compared to their white counterparts. The study surveyed older adults on their perceptions of MRI scans, willingness to learn scan results, and attitudes towards research participation and dementia.

Findings indicate a need for culturally sensitive approaches to encourage participation and improve representation in health studies. Addressing these hesitancies could lead to more inclusive research outcomes and better understanding of health issues affecting diverse populations.

Key Facts:

1. South Asian and East Asian older adults show less interest than white older adults in learning about MRI scan findings and participating in research not directly beneficial to them.

2. The study highlights the importance of understanding and addressing the concerns of different Asian American subgroups to enhance research diversity.

3. Supported by Rutgers Institute for Health and other initiatives, this research underscores the need for culturally tailored recruitment strategies in health studies.

Source: Rutgers University

Asian Americans are less likely than their white peers to participate in health research involving MRIs and addressing this hesitancy could improve research, according to a Rutgers Health-led study.

Findings by the researchers, published in Alzheimer’s & Dementia: Translational Research & Clinical Interventions, a journal of the Alzheimer’s Association, surveyed older adults about their experiences and perceptions of MRI brain imaging scans, their desire to learn results of scans and their attitudes related to dementia and overall research participation.

According to the study, South Asian older adults – those 65 and older – are less likely than older white adults to believe that healthy people should participate in research studies when it may not benefit them.

South Asian and East Asian older adults also have less desire to learn about findings from an MRI brain scan – commonly used in clinical research studies – than older white adults.

“Addressing hesitancy toward participation may improve representation of a group that does not usually take part in research studies,” said Karthik Kota, an assistant professor of medicine and a geriatrician at Rutgers Robert Wood Johnson Medical School and lead author of the study.

Asian Americans represent the fastest-growing racial group in the United States and the fastest-growing group of adults over 65. As age is the biggest risk factor for dementia, this group is at higher risk for dementia. In a prior pilot study, Rutgers Health researchers encountered unexpected hesitancy from these groups related to MRI scans.

In the latest study, 256 respondents answered what type of MRI results they wanted to learn of – including receiving serious findings without treatment options or benign ones common with aging – and questions on research and brain health attitudes.

Researchers found similarly low desire to learn of MRI results in South Asians and East Asians despite the groups showing differing support for research participation and future dementia or stroke worries.

Researchers said the findings reinforce the need to separate different Asian American subgroups when conducting health-related research.

“Understanding concerns older Asian adults have about MRI brain findings could allow for more culturally appropriate return of scan results,” Kota said.

“Progress in this area will not only affect how researchers recruit for studies, but also the expectations that the public may have when interacting with researchers.”

Research was supported by the Resource Center for Alzheimer’s and Dementia Research in Asian and Pacific Americans at the Rutgers Institute for Health, Health Care Policy and Aging Research (IFH), as well as the South Asian Total Health Initiative and the RWJBarnabas Health Chinese Medical Program.

Coauthors of the study include Alice Dawson, Julia Papas, Victor Sotelo and William Hu of the Department of Neurology at Rutgers Robert Wood Johnson Medical School and the Center for Healthy Aging at IFH; and Guibin Su, Mei-Ling Li, Woowon Lee, Jaunis Estervil, Melissa Marquez, Shromona Sarkar and Lisa Lanza of IFH.

Women Scan For Danger When Walking at Night

Neuroscience

·February 9, 2024

Summary: A new study highlights the stark differences in how men and women perceive safety while walking at night.

Through an innovative use of heat maps generated by participants’ focus on photographs of campus areas, the study found women were significantly more likely to scan for potential safety hazards in their surroundings, unlike men who focused on direct paths or specific objects.

This research, involving nearly 600 participants, underscores the gender-specific experiences of navigating public spaces after dark, calling for inclusive urban planning that addresses these distinct safety perceptions.

Key Facts:

1. Women participants consistently scanned for potential safety hazards around the periphery of images, indicating a unique concern for safety while walking at night.

2. Men’s attention was primarily directed towards paths and fixed objects, showing a different approach to navigating public spaces.

3. The study’s findings suggest the need for urban and campus planning to consider the diverse safety needs and perceptions of all genders to create more inclusive environments.

Source: Brigham Young University

An eye-catching new study shows just how different the experience of walking home at night is for women versus men.

The study, led by Brigham Young University public health professor Robbie Chaney, provides clear visual evidence of the constant environmental scanning women conduct as they walk in the dark, a safety consideration the study shows is unique to their experience.

Chaney and co-authors Alyssa Baer and Ida Tovar showed pictures of campus areas at four Utah universities — Utah Valley University, Westminster, Brigham Young University and University of Utah — to participants and asked them to click on areas in the photos that caught their attention.

Women focused significantly more on potential safety hazards — the periphery of the images — while men looked directly at focal points or their intended destination.

“The resulting heat maps represent perhaps what people are thinking or feeling or doing as they are moving through these spaces,” Chaney said. “Before we started the study, we expected to see some differences, but we didn’t expect to see them so contrasting. It’s really visually striking.”

Nearly 600 individuals took part in the study, published recently in the journal Violence and Gender, with 56% of participants being female and 44% being male. Each participant looked at 16 images and were told to imagine themselves walking through those areas. They used a Qualtrics heat map tool to click on the areas of the image that stood out the most to them.

While men tended to focus on the path or a fixed object (like a light, the walking path or a garbage can), the women’s visual pattern represented a scanning of the perimeter (bushes, dark areas next to a path).

Chaney, along with Baer and Tovar — both BYU undergrads at the time of the study’s inception — say the findings provide some insight into what it is like to walk home as a woman, which could be multiplied through years or a lifetime of experiences.

“This project has been a fantastic conversation starter to bring awareness to lived experiences, particularly of women in this case,” said Baer, who recently finished graduate school at George Washington University and now works in Washington, D.C. “My hope is that in having concrete data we are able to start conversations that lead to meaningful action.”

Authors said the data suggests that because environment is perceived and experienced differently by women and men, decision makers in building campus and community environments should consider the varied experiences, perceptions and safety of both.

“Why can’t we live in a world where women don’t have to think about these things? It’s heartbreaking to hear of things women close to me have dealt with,” Chaney said. “It would be nice to work towards a world where there is no difference between the heat maps in these sets of images. That is the hope of the public health discipline.”

https://neurosciencenews.com/women-walking-vision-night-25595/

https://www.jugantor.com/international/770417/যুক্তরাষ্ট্রের-পর-উগ্র-ইসরাইলিদের-ওপর-নিষেধাজ্ঞার-কথা-ভাবছে-কানাডা

https://www.prothomalo.com/world/m9s7mbs5la

Fasting May Reduce Inflammation

https://neurosciencenews.com/fasting-inflammation-25546/

·January 31, 2024

Summary: Researchers uncovered a new mechanism by which fasting reduces inflammation, a key factor in chronic diseases.

Their study reveals that fasting increases blood levels of arachidonic acid, which inhibits the NLRP3 inflammasome, thereby reducing inflammation. This discovery sheds light on the anti-inflammatory effects of fasting and offers insights into the benefits of calorie restriction for conditions like obesity, diabetes, heart disease, and neurodegenerative disorders.

The research also provides clues to how drugs like aspirin might function, further highlighting the intricate relationship between diet, inflammation, and disease prevention.

Key Facts:

1. Fasting elevates arachidonic acid levels in the blood, leading to reduced activity of the NLRP3 inflammasome and inflammation.

2. The findings offer a potential explanation for how fasting and calorie restriction can protect against chronic inflammation-related diseases.

3. This research may also explain the anti-inflammatory effects of non-steroidal anti-inflammatory drugs like aspirin, which increase arachidonic acid levels.

Source: University of Cambridge

Cambridge scientists may have discovered a new way that fasting helps reduce inflammation, a potentially damaging side-effect of the body’s immune system that underlies a number of chronic diseases.

In a paper titled “Arachidonic acid inhibition of the NLRP3 inflammasome is a mechanism to explain the anti-inflammatory effects of fasting,” published in Cell Reports, the team describes how fasting raises levels of a chemical in the blood known as arachidonic acid, which inhibits inflammation.

The researchers say it may also help explain some of the beneficial effects of drugs such as aspirin.

Scientists have known for some time that our diet—particularly a high-calorie Western diet—can increase our risk of diseases including obesity, type 2 diabetes and heart disease, which are linked to chronic inflammation in the body.

Studies have shown that some patients who have a high-fat diet have increased levels of inflammasome activity. Credit: Neuroscience News

Inflammation is our body’s natural response to injury or infection, but this process can be triggered by other mechanisms, including by the so-called “inflammasome,” which acts like an alarm within our body’s cells, triggering inflammation to help protect our body when it senses damage.

But the inflammasome can trigger inflammation in unintentional ways—one of its functions is to destroy unwanted cells, which can result in the release of the cell’s contents into the body, where they trigger inflammation.

Professor Clare Bryant from the Department of Medicine at the University of Cambridge said, “We’re very interested in trying to understand the causes of chronic inflammation in the context of many human diseases, and in particular the role of the inflammasome.

“What’s become apparent over recent years is that one inflammasome in particular—the NLRP3 inflammasome—is very important in a number of major diseases such as obesity and atherosclerosis, but also in diseases like Alzheimer’s and Parkinson’s disease, many of the diseases of older age people, particularly in the Western world.”

Fasting can help reduce inflammation, but the reason why has not been clear. To help answer this question, a team led by Professor Bryant and colleagues at the University of Cambridge and National Institute for Health in the U.S. studied blood samples from a group of 21 volunteers, who ate a 500-kcal meal and then fasted for 24 hours before consuming a second 500-kcal meal.

The team found that restricting calorie intake increased levels of a lipid known as arachidonic acid. Lipids are molecules that play important roles in our bodies, such as storing energy and transmitting information between cells. As soon as individuals ate a meal again, levels of arachidonic acid dropped.

When the researchers studied arachidonic acid’s effect in immune cells cultured in the lab, they found that it turns down the activity of the NLRP3 inflammasome. This surprised the team, as arachidonic acid was previously thought to be linked with increased levels of inflammation, not decreased levels.

Professor Bryant, a Fellow of Queens’ College, Cambridge, added, “This provides a potential explanation for how changing our diet—in particular by fasting—protects us from inflammation, especially the damaging form that underpins many diseases related to a Western high-calorie diet.

“It’s too early to say whether fasting protects against diseases like Alzheimer’s and Parkinson’s disease, as the effects of arachidonic acid are only short-lived, but our work adds to a growing amount of scientific literature that points to the health benefits of calorie restriction. It suggests that regular fasting over a long period could help reduce the chronic inflammation we associate with these conditions. It’s certainly an attractive idea.”

The findings also hint at one mechanism whereby a high-calorie diet might increase the risk of these diseases. Studies have shown that some patients who have a high-fat diet have increased levels of inflammasome activity.

“There could be a yin and yang effect going on here, whereby too much of the wrong thing is increasing your inflammasome activity and too little is decreasing it,” said Professor Bryant. “Arachidonic acid could be one way in which this is happening.”

The researchers say the discovery may also offer clues to an unexpected way in which so-called non-steroidal anti-inflammatory drugs such as aspirin work. Normally, arachidonic acid is rapidly broken down in the body, but aspirin stops this process, which can lead to an increase in levels of arachidonic acid, which in turn reduce inflammasome activity and hence inflammation.

Professor Bryant said, “It’s important to stress that aspirin should not be taken to reduce risk of long terms diseases without medical guidance, as it can have side effects such as stomach bleeds if taken over a long period.”

City Life’s Influence on Unconscious Racial Bias

Featured Psychology

·February 6, 2024

Summary: A new study links the structure of urban environments to the development of unconscious racial biases among its residents. By analyzing data from the Implicit Association Test (IAT) and U.S. Census demographics, researchers have created a model showing that cities with larger, more diverse, and less segregated social networks tend to have lower levels of implicit racial bias.

The study highlights the role of city organization in systemic racism, suggesting that urban planning and community engagement could be key to reducing prejudice. It underscores the importance of integrating diverse communities and promoting inclusive public spaces as strategies for fostering equitable urban living and mitigating racial biases.

Key Facts:

1. The study analyzed implicit racial bias using IAT scores from approximately 2.7 million individuals, correlating these with urban demographics and population data.

2. Findings indicate that cities with less segregation and greater diversity in social networks show reduced implicit racial biases among residents.

3. The research suggests structural changes in urban planning could help diminish unconscious racial prejudices, highlighting the impact of city living on social attitudes.

Source: Santa Fe Institute

The city you live in could be making you, your family, and your friends more unconsciously racist. Or, your city might make you less racist. It depends on how populous, diverse, and segregated your city is, according to a new study that brings together the math of cities with the psychology of how individuals develop unconscious racial biases.

The study, published in the latest issue of Nature Communications, presents data and a mathematical model of exposure and adaptation in social networks that can help explain why there is more unconscious, or implicit, racial bias in some cities than others. The authors hope that local communities and governments can use the findings to help create more just and equitable cities.

“What I think is most interesting is the implication that there’s a piece of systemic racism that has to do with how people learn and the way cities are organized,” says psychologist Andrew Stier, an SFI Complexity Postdoctoral Fellow and lead author of the study.

Cities create dense networks of social interaction between people. Because of the interactions with many different people, we need to be constantly adapting to new situations and learning, explains SFI External Professor Luís Bettencourt(University of Chicago), a co-leader of SFI’s Cities, Scaling and Sustainability project and co-author of the study.

To see how racial biases emerge from how U.S. cities are organized, Stier turned to the enormous database of the Implicit Association Test (IAT). In the popular online test, volunteer participants are given a pairing of White or Black faces with positive or negative words and asked to categorize a single face or word.

If they are faster to categorize things when White/good are paired they have a White-good bias and if they are faster to categorize things when Black/good are paired they have a Black-good bias.

“People may feel they are not prejudiced, but can unconsciously have a preference for one group or another, and this is revealed by these tests,” Stier says.

The researchers took the average IAT bias scores from approximately 2.7 million individuals in different geographic areas and linked them to racial demographics and population data from the U.S.

Census to build a model that accounts for how individuals learn biases through their social networks. They found that when these networks are larger, more diverse, and less segregated in cities, implicit racial biases decrease.

The results suggest that there are structural reasons why cities help or deter people from becoming less racially biased. Perhaps the most pronounced reason is the segregation of different racial groups into different neighborhoods. Related to that is the lack of more cosmopolitan public spaces where a diverse range of people can experience positive interactions with one another.

In cities where people can’t encounter and interact with people and institutions used by other groups, racial biases create major barriers to equity.

These barriers are associated with disparities across essentially all aspects of life including medical care, education, employment, policing, mental health outcomes, and physical health, the authors explain.

https://neurosciencenews.com/city-life-psychology-racism-25565/

How Odors Influence Brain’s Decision Making Mechanism

·February 6, 2024

Summary: Researchers have uncovered a novel function of the hippocampus in decision making, showing that specific brain cells, known as ‘time cells,’ are stimulated by odors to facilitate rapid ‘go, no-go’ decisions.

This study demonstrates how mice learned to associate fruity odors with a reward, leading to quicker and more efficient decision making.

By tracking the activation of these cells in response to scents, the team has revealed a direct link between odor, hippocampal function, and associative learning, suggesting that these cells play a crucial role beyond memory recall, directly influencing the brain’s decision-making process.

Key Facts:

1. The study identifies ‘time cells’ in the hippocampus as key players in the brain’s decision-making process, stimulated by specific odors to trigger rapid decisions.

2. Mice were able to associate fruity smells with positive outcomes, showing how odor cues can enhance the learning of decision-making behaviors.

3. This research sheds light on the intricate relationship between sensory perception and cognitive processes, revealing new insights into the hippocampus’s role in associative learning and decision making.

Source: University of Colorado

Researchers at the University of Colorado Anschutz Medical Campus have discovered that odors stimulate specific brain cells that may play a role in rapid `go, no-go’ decision making.

The study was published online Tuesday in the journal Current Biology.

The scientists focused on the hippocampus, an area of the brain crucial to memory and learning. They knew that so-called `time cells’ played a major role in hippocampal function but didn’t know their role in associative learning.

“These are cells that would remind you to make a decision – do this or do that,” said the study’s senior author Diego Restrepo, PhD, a neuroscientist and professor of cell and developmental biology at the University of Colorado School of Medicine.

The researchers observed that when mice were given the choice of responding to a fruity smell by licking on a spout that delivered sweet water, they quickly learned to lick the fruity smell as opposed to the smell of mineral oil.

“They have to associate the odor with the outcome of what they are doing so that’s why they learn decision making,” said Ming Ma, PhD, a first author of the study and a senior instructor in cell and developmental biology at the CU School of Medicine. “When it’s a fruit odor, they lick and get a reward. When it’s mineral oil they stop licking.”

“The more they learned, the more the cells were stimulated leading to more rapid decoding of the odors and allowing the mice to quickly become proficient at choosing the fruity smell,” said Fabio Simoes de Souza, DSc, another first author of the study and an assistant research professor in cell and developmental biology at the CU School of Medicine.

The catalyst for the decision-making is the odor which travels up the nose sending neural signals to the olfactory bulb and to the hippocampus. The two organs are closely connected. The information is swiftly processed and the brain makes a decision based on the input.

“Before this we didn’t know there were decision making cells in the hippocampus,” Restrepo said. “The hippocampus is multitasking.”

The cells are not always turned on, Restrepo speculated, because otherwise the stimuli might become overwhelming.

The study expands current knowledge of what’s involved in decision-making in the brain, specifically those quick go, no-go decisions that mice and humans make all the time.

“The hippocampus turns on decision-predicting time cells which would give you a hint of what to remember,” Restrepo said. “In the past, time cells were thought to only remind you of events and time. Here we see memory encoded in the neurons and then retrieved instantly when making a decision.”

https://neurosciencenews.com/odor-hippocampus-decision-making-25568/

Depression Linked to Higher Body Temperatures

https://neurosciencenews.com/

·February 5, 2024

Summary: A new study suggests a novel link between depression and higher body temperatures, analyzing data from over 20,000 participants worldwide. While the causal relationship remains unclear, findings indicate that body temperature increases with the severity of depression symptoms, offering a potential new avenue for treatment.

The research, leveraging wearable technology for temperature measurement, hints at the benefits of heat-based treatments like saunas for depression, potentially by inducing the body to lower temperatures through mechanisms like sweating. This study opens the door to exploring temperature regulation as a therapeutic strategy for depression, highlighting an innovative approach to addressing rising depression rates globally.

Key Facts:

1. The study observed a correlation between increased depression symptom severity and higher body temperatures in participants from 106 countries.

2. It explored the potential of heat-based treatments (e.g., saunas) to reduce depression by triggering the body’s natural cooling responses.

3. This research is one of the largest to examine the association between body temperature and depression symptoms, utilizing wearable sensors and self-reported data.

Source: UCSF

People with depression have higher body temperatures, suggesting there could be a mental health benefit to lowering the temperatures of those with the disorder, a new UC San Francisco-led study found.

The study, published today in Scientific Reports, doesn’t indicate whether depression raises body temperature or a higher temperature causes depression. It’s also unknown whether the higher body temperature observed in people with depression reflects decreased ability to self-cool, increased generation of heat from metabolic processes or a combination of both.

Researchers analyzed data from more than 20,000 international participants who wore a device that measures body temperature, and also self-reported their body temperatures and depression symptoms daily. The seven-month study began in early 2020 and included data from 106 countries.

The results showed that with each increasing level of depression symptom severity, participants had higher body temperatures. The body temperature data also showed a trend toward higher depression scores in people whose temperatures had less fluctuation throughout a 24-hour period, but this finding didn’t reach significance.

The findings shed light on how a novel depression treatment method might work, said Ashley Mason, Ph.D., the study’s lead author and associate professor of psychiatry at UCSF Weill Institute for Neurosciences.

A small body of existing, causal studies has found that using hot tubs or saunas can reduce depression, possibly by triggering the body to self-cool, for example, through sweating.

“Ironically, heating people up actually can lead to rebound body temperature lowering that lasts longer than simply cooling people down directly, as through an ice bath,” said Mason, who is also a clinical psychologist at the UCSF Osher Center for Integrative Health.

“What if we can track the body temperature of people with depression to time heat-based treatments well?”

“To our knowledge, this is the largest study to date to examine the association between body temperature—assessed using both self-report methods and wearable sensors—and depressive symptoms in a geographically broad sample,” added Mason.

“Given the climbing rates of depression in the United States, we’re excited by the possibilities of a new avenue for treatment.”

Fruit Flies’ Sensory Evolution: A Whiff of Genetic Secrets

Featured Genetics Neuroscience

·February 5, 2024

Summary: Researchers mapped the sensory evolution of fruit flies, revealing how genetic variations enable them to adapt their sense of smell and taste to diverse environments.

The team discovered that while most genes remain stable across generations, a significant number have evolved, leading to unique olfactory experiences among different fly species.

This study not only highlights the role of stabilising selection in maintaining gene expression levels but also uncovers male-biased gene expression in scent detection, pointing towards sex-specific evolutionary paths.

These findings not only deepen our understanding of fruit flies’ sensory adaptations but also shed light on the broader mechanisms of sensory system evolution across species.

Key Facts:

1. Researchers found a mix of stabilising selection and significant gene expression changes in Drosophila species, shaping their olfactory senses.

2. The study identified male-biased gene expression in the front legs of D. melanogaster, suggesting a special role in male scent detection.

3. This research offers insights into the evolutionary dynamics of sensory systems, with implications for understanding sex differences and sensory perception in a wide range of organisms.

Source: Queen Mary University London

A new study in Nature Communications unveils the hidden world of sensory evolution in fruit flies. By delving into the genes and cells behind their delicate noses and tongues, researchers have discovered surprising secrets about how these tiny insects adapt their senses to different environments.

“Imagine a world where a ripe peach tastes and smells like tangy vinegar to one fly, but like a burst of summer to another,” explains principal author of the study Dr Roman Arguello, a Lecturer in Genetics, Genomics and Fundamental Cell Biology at Queen Mary University of London. “Our study shows that this is not just possible, but it’s actually quite common.”

The research team analysed the gene expression patterns in five key scent-detecting tissues across six different Drosophila species. This comprehensive approach allowed them to delve deeper than ever before into the molecular underpinnings of smell.

One surprising discovery was the prevalence of “stabilising selection,” a force that keeps most genes expressed at the same levels across generations. However, within this sea of stability, the researchers found thousands of genes that had undergone significant changes in expression, shaping the unique olfactory landscapes of different fly species.

“It’s like finding hidden islands of diversity within a vast ocean of uniformity,” says Dr Arguello. “These changes in gene expression tell us about the evolution of new smells, new sensitivities, and even new ways of using scent to navigate the world.”

The study also reveals intriguing differences between the sexes. In fruit flies, as in many other animals, males and females often experience the world through different olfactory lenses.

The researchers identified a surprising excess of male-biased gene expression in the front legs of D. melanogaster, suggesting that these limbs play a crucial role in male-specific scent detection.

“These findings open up exciting new avenues for understanding how sex differences evolve and how they impact animal behavior,” says Dr Arguello.

The study’s implications extend beyond the fascinating world of flies. It provides valuable insights into the general principles of how sensory systems evolve, offering clues to understanding how other animals, including humans, perceive their chemical environments.

https://neurosciencenews.com/genetics-sensory-evolution-25563/

How the Brain Crafts Words Before Speaking

Summary: A new study utilizes advanced Neuropixels probes to unravel the complexities of how the human brain plans and produces speech. The team identified specific neurons in the prefrontal cortex involved in the language production process, including the separate neural pathways for speaking and listening.

Their findings illustrate how the brain represents phonemes and assembles them into syllables, providing insights that could revolutionize treatments for speech and language disorders.

This research not only enhances our understanding of the neural underpinnings of speech but also opens the door to developing technologies for synthetic speech production, offering hope for individuals with neurological disorders affecting communication.

Key Facts:

1. Neuropixels probes were used to record activities of individual neurons involved in planning and producing speech, revealing the brain’s intricate processes for language production.

2. The study identified separate groups of neurons dedicated to speaking and listening, and how the brain constructs speech sounds before they are spoken.

3. This research could lead to the development of synthetic speech prosthetics and treatments for a wide range of neurological disorders affecting speech and language.

Source: Mass General

By using advanced brain recording techniques, a new study led by researchers from Massachusetts General Hospital (MGH) demonstrates how neurons in the human brain work together to allow people to think about what words they want to say and then produce them aloud through speech.

Together, these findings provide a detailed map of how speech sounds such as consonants and vowels are represented in the brain well before they are even spoken and how they are strung together during language production.

The work, which is published in Nature, reveals insights into the brain’s neurons that enable language production, and which could lead to improvements in the understanding and treatment of speech and language disorders.

“Although speaking usually seems easy, our brains perform many complex cognitive steps in the production of natural speech—including coming up with the words we want to say, planning the articulatory movements and producing our intended vocalizations,” says senior author Ziv Williams, MD, an associate professor in Neurosurgery at MGH and Harvard Medical School.

“Our brains perform these feats surprisingly fast—about three words per second in natural speech—with remarkably few errors. Yet how we precisely achieve this feat has remained a mystery.”

When they used a cutting-edge technology called Neuropixels probes to record the activities of single neurons in the prefrontal cortex, a frontal region of the human brain, Williams and his colleagues identified cells that are involved in language production and that may underlie the ability to speak. They also found that there are separate groups of neurons in the brain dedicated to speaking and listening.

“The use of Neuropixels probes in humans was first pioneered at MGH. These probes are remarkable—they are smaller than the width of a human hair, yet they also have hundreds of channels that are capable of simultaneously recording the activity of dozens or even hundreds of individual neurons,” says Williams who had worked to develop these recording techniques with Sydney Cash, MD, PhD, a professor in Neurology at MGH and Harvard Medical School, who also helped lead the study.

“Use of these probes can therefore offer unprecedented new insights into how neurons in humans collectively act and how they work together to produce complex human behaviors such as language.”

The study showed how neurons in the brain represent some of the most basic elements involved in constructing spoken words—from simple speech sounds called phonemes to their assembly into more complex strings such as syllables.

For example, the consonant “da”, which is produced by touching the tongue to the hard palate behind the teeth, is needed to produce the word dog.

By recording individual neurons, the researchers found that certain neurons become active before this phoneme is spoken out loud. Other neurons reflected more complex aspects of word construction such as the specific assembly of phonemes into syllables.

With their technology, the investigators showed that it’s possible to reliably determine the speech sounds that individuals will say before they articulate them.

In other words, scientists can predict what combination of consonants and vowels will be produced before the words are actually spoken. This capability could be leveraged to build artificial prosthetics or brain-machine interfaces capable of producing synthetic speech, which could benefit a range of patients.

“Disruptions in the speech and language networks are observed in a wide variety of neurological disorders—including stroke, traumatic brain injury, tumors, neurodegenerative disorders, neurodevelopmental disorders, and more,” says Arjun Khanna who is a co-author on the study.

“Our hope is that a better understanding of the basic neural circuitry that enables speech and language will pave the way for the development of treatments for these disorders.”

The researchers hope to expand on their work by studying more complex language processes that will allow them to investigate questions related to how people choose the words that they intend to say and how the brain assembles words into sentences that convey an individual’s thoughts and feelings to others.

Additional authors include William Muñoz, Young Joon Kim, Yoav Kfir, Angelique C. Paulk, Mohsen Jamali, Jing Cai, Martina L Mustroph, Irene Caprara, Richard Hardstone, Mackenna Mejdell, Domokos Meszena, Abigail Zuckerman, and Jeffrey Schweitzer..

Funding: This work was supported by the National Institutes of Health.

https://neurosciencenews.com/speech-production-neurons-25549/

Mapping the Brain: The Largest Neuron Projectome Unveiled

Electrophysiology Featured Neuroscience

·February 1, 2024

Summary: Researchers unveiled the most extensive single-neuron projectome database to date, featuring over 10,000 mouse hippocampal neurons.

The study provides an unprecedented view of the spatial connectivity patterns at the mesoscopic level, crucial for understanding learning, memory, and emotional processing in the hippocampus. By employing machine learning algorithms for categorizing axonal trajectories and integrating spatial transcriptome data, researchers identified 43 distinct projectome cell types, revealing intricate projection patterns and soma locations’ correspondence to projection targets.

This work, accessible via the Digital Brain CEBSIT portal, lays the structural foundation for advancing our knowledge of hippocampal functions and their molecular underpinnings.

Key Facts:

1. The study reconstructed whole-brain axonal morphology of over 10,000 mouse hippocampal neurons, creating the world’s most extensive single-neuron projectome database.

2. Researchers used machine learning to analyze morphological similarities among neurons, identifying 43 distinct projectome cell types.

3. The integration of projectome cell types with spatial transcriptome data revealed potential molecular and circuit targets for hippocampal functions, all accessible through a dedicated online platform.

Source: Chinese Academy of Science

A study published in Science on Feb. 1 reported a comprehensive database of single-neuron projectomes consisting of over 10,000 mouse hippocampal neurons, thus revealing the spatial connectivity patterns of mouse hippocampal neurons at the mesoscopic level.

The study was conducted by teams from the Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), the Institute of Neuroscience of the Chinese Academy of Sciences (CAS), the HUST-Suzhou Institute for Brainsmatics, Hainan University, the Kunming Institute of Zoology of CAS, Lingang Laboratory, and the Shanghai Center for Brain Science and Brain-Inspired Technology.

The hippocampus serves as an essential brain region for learning and memory as well as various brain functions such as spatial cognition and emotional processing. It is one of the most extensively studied brain regions.

Hippocampal neurons project widely to the brain-wide targets; thus, it is critical to investigate the projection patterns of hippocampal neurons at the single-neuron level.

This study reconstructed the whole-brain axonal morphology of over 10,000 neurons in the mouse hippocampus at a single-cell resolution with the neuronal cell bodies covering all subregions and multiple locations along different hippocampal axes, making this the most extensive single-neuron projectome database in the world.

This study took an innovative approach to categorize axonal trajectories with machine learning algorithms, thus allowing for a more efficient analysis of the morphological similarities among 341 projection patterns for mouse hippocampal neurons and ultimately identifying 43 distinct projectome cell types. It also incorporated the spatial transcriptome of mouse CA1 areas.

Based on these analyses, the study was able to elucidate the axonal projection pathways of hippocampal neurons along the anterior-posterior axis and reveal new projection patterns of hippocampal neurons. It also outlined the correspondence between hippocampal neuron soma locations and projection targets, and revealed basic organization principles of bilateral projections.

Furthermore, correlation analysis of projectome cell types and spatial transcriptome data identified spatial correspondence between various genes and projectome subtypes, providing potential molecular and circuit targets for hippocampal functions.

Taken together, this study provides a structural basis for future studies of hippocampal functions and deciphers the potential correspondences between their soma locations, gene expression, and circuitry functions.

The database for the hippocampal single-neuron projectomes, along with the database on the hippocampal longitudinal axis and spatial transcriptomes, are now publicly accessible through the Digital Brain CEBSIT portal (https://mouse.digital-brain.cn/hipp).

To facilitate broader usage of the databases, a team from the Computing and Data Center of CEBSIT has developed a website to integrate data visualization, user interface, online analysis, and data downloads.

https://neurosciencenews.com/hippocampus-projectome-25550/

Diet and Immunity: Vegan vs. Keto’s Impact on the Body

Summary: A new study reveals distinct immune system responses to vegan and ketogenic diets. Over a two-week period, 20 participants alternated between these diets, allowing researchers to observe changes in innate and adaptive immunity, metabolic pathways, and gut microbiome.

The vegan diet primarily affected innate immunity and red blood cell pathways, while the keto diet influenced adaptive immunity and a wider range of proteins. These findings highlight the rapid and diverse immune responses to dietary changes, opening avenues for diet-based disease prevention and treatment strategies.

Key Facts:

1. The vegan diet triggered innate immune responses and affected pathways related to red blood cells, while the keto diet influenced adaptive immunity and a broader range of protein levels.

2. Both diets significantly altered participants’ microbiomes and metabolic processes.

3. The study’s controlled environment and diverse participant group demonstrate that dietary changes can consistently affect complex bodily systems.

Source: NIH

Researchers at the National Institutes of Health observed rapid and distinct immune system changes in a small study of people who switched to a vegan or a ketogenic (also called keto) diet. Scientists closely monitored various biological responses of people sequentially eating vegan and keto diets for two weeks, in random order.

They found that the vegan diet prompted responses linked to innate immunity—the body’s non-specific first line of defense against pathogens—while the keto diet prompted responses associated with adaptive immunity—pathogen-specific immunity built through exposures in daily life and vaccination.

The work is published in the journal Nature Medicine.

Metabolic changes and shifts in the participants’ microbiomes—communities of bacteria living in the gut—were also observed. More research is needed to determine if these changes are beneficial or detrimental and what effect they could have on nutritional interventions for diseases such as cancer or inflammatory conditions.

Scientific understanding of how different diets impact the human immune system and microbiome is limited. Therapeutic nutritional interventions—which involve changing the diet to improve health—are not well understood, and few studies have directly compared the effects of more than one diet.

The keto diet is a low-carbohydrate diet that is generally high in fat. The vegan diet eliminates animal products and tends to be high in fiber and low in fat.

The study was conducted by researchers from the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at the Metabolic Clinical Research Unit in the NIH Clinical Center. The 20 participants were diverse with respect to ethnicity, race, gender, body mass index (BMI), and age.

Each person ate as much as desired of one diet (vegan or keto) for two weeks, followed by as much as desired of the other diet for two weeks. People on the vegan diet, which contained about 10% fat and 75% carbohydrates, chose to consume fewer calories than those on the keto diet, which contained about 76% fat and 10% carbohydrates.

Throughout the study period, blood, urine, and stool were collected for analysis. The effects of the diets were examined using a “multi-omics” approach that analyzed multiple data sets to assess the body’s biochemical, cellular, metabolic, and immune responses, as well as changes to the microbiome. Participants remained on site for the entire month-long study, allowing for careful control of the dietary interventions.

Switching exclusively to the study diets caused notable changes in all participants. The vegan diet significantly impacted pathways linked to the innate immune system, including antiviral responses.

On the other hand, the keto diet led to significant increases in biochemical and cellular processes linked to adaptive immunity, such as pathways associated with T and B cells.

The keto diet affected levels of more proteins in the blood plasma than the vegan diet, as well as proteins from a wider range of tissues, such as the blood, brain and bone marrow. The vegan diet promoted more red blood cell-linked pathways, including those involved in heme metabolism, which could be due to the higher iron content of this diet.

Additionally, both diets produced changes in the microbiomes of the participants, causing shifts in the abundance of gut bacterial species that previously had been linked to the diets.

The keto diet was associated with changes in amino acid metabolism—an increase in human metabolic pathways for the production and degradation of amino acids and a reduction in microbial pathways for these processes—which might reflect the higher amounts of protein consumed by people on this diet.

The distinct metabolic and immune system changes caused by the two diets were observed despite the diversity of the participants, which shows that dietary changes consistently affect widespread and interconnected pathways in the body. More study is needed to examine how these nutritional interventions affect specific components of the immune system.

According to the authors, the results of this study demonstrate that the immune system responds surprisingly rapidly to nutritional interventions. The authors suggest that it may be possible to tailor diets to prevent disease or complement disease treatments, such as by slowing processes associated with cancer or neurodegenerative disorders.

https://neurosciencenews.com/keto-vegan-immunity-25547/

প্রতিরাতে যে বিছানায় ঘুমান, শরীর তাতে এলিয়ে দিতেই ঘুম আসে। হয়তো বলবেন, ক্লান্তি থেকে এমন হয়। চেনা পরিবেশে ঘুম যেন আপনাতে এসে যায়।

কিন্তু নতুন একটি জায়গায় গেলেন। হতে পারে কোথাও বেড়াতে গেলেন, হতে পারে হলে কিংবা হোস্টেলে প্রথম উঠেছেন, হতে পারে সেন্টমার্টিনে গেছেন প্রথম রাত্রি যাপন করতে এক হোটেলে। মাঝ রাতে কোনো কারণ ছাড়াই ঘুম ভেঙে গেল, তারপর চেষ্টা করছেন ঘুমাতে। যেন আর ঘুম আসে না রাতে।

আরও পড়ুন: খোসপাঁচড়া রোগ হলে যা করবেন

যেখানেই যান, নতুন পরিবেশে সহজে ঘুম আসে না। এটি হয়তো আমরা স্বাভাবিক ভাবি। প্রথম রাতটি যেন একটু ঘুম, একটু ঘুমের ব্যাঘাতে কাটে। ঘুমের চেয়ে এপাশ ওপাশ হয় বেশি। ঘুমের চেয়ে ঘুম ভেঙে যায় বেশি।

অথচ শরীর ক্লান্ত। পরিবেশ সুন্দর। নরম বিছানা। মনে কোনো দুশ্চিন্তা নেই। তারপরও কেন এমন হয়। কেন অচেনা, অজানা নতুন পরিবেশে আমাদের ঘুম আসে না সহজে!

নতুন পরিবেশে ঘুমের এ সমস্যাটি সম্পর্কে চিকিৎসকরা অনেক দিন থেকে জানে। চিকিৎসকদের কাছে এটির নাম : First-Night Effect। সংক্ষেপে বলে FNE। এক দশক আগেই এ সম্পর্কে চিকিৎসক বিজ্ঞানীরা ধারণা পায়।

যে কোনো নতুন পরিবেশে ঘুমের কমতি হওয়াকে বলে এই FNE। এটি মূলত প্রথম রাতেই বেশি হয়। তার পরের রাতগুলোতে হয় না অথবা হলে অনেক কম হয় ঘুমের সমস্যা।

First Night Effect (FNE)-এর কারণে ঘুমের আর্কিটেকচারের পরিবর্তন হয়। ঘুমের যে দুটি স্টেজ REM এবং Non-REM, তাদের REM স্টেজটির পরিবর্তন হয়। তাতে ঘুমের পরিমাণ কমে যায়, চোখ বন্ধ থাকলেও কোয়ালিটি ঘুম হয় না।

অনেকদিন থেকে ভাবা হতো যে নতুন পরিবেশের সঙ্গে খাপ খাইয়ে নিতে সময় নেয় বলে হয়তো এমন হয়। অনেকেই ভাবত যে বিছানা বদল মানে ঘুমের ধকল! ঘুমের উপকরণের সঙ্গে অ্যাডজাস্ট হতে সময় নিচ্ছে বলে এমন হয়।

এ নিয়ে বিজ্ঞানীরা কাজ করতে গিয়ে দেখতে পেল অন্য জিনিস। আমরা যখন ঘুমাই, মস্তিষ্কের সব অংশই ঘুমায়। মানুষের মস্তিষ্ক দুটি ভাগে বিভক্ত। এক একটি ভাগকে হেমিস্ফিয়ার বলে। সহজ করে বললে ডান মস্তিষ্ক এবং বাম মস্তিষ্ক। ঘুমাতে গেলে ডান এবং বাম, দু’মস্তিষ্কই একসঙ্গে সমন্বয় করে এবং ঘুমায়।

আরও পড়ুন: হার্ট সুস্থ রাখতে যেভাবে নিবেন মুখের যত্ন

ঘুমের দুটি স্টেজ আছে সঙ্গে। একটিকে বলে REM বা Rapid Eye Movement-যেখানে চোখ ঘুরে। আরেকটি হলো Non REM-যেখানে চোখ ঘোরে না। ঘুমের শুরুতে Non REM ধাপ শুরু হয়। ধীরে ধীরে REM স্টেজে ঘুম গভীর হয় এবং এই স্টেজেই মানুষ স্বপ্ন দেখে।

বিজ্ঞানীরা নতুন জায়গায় ঘুমের এমন ব্যাঘাত হয় কেন, তার কারণ জানার এবং চেষ্টার অনেক আগ থেকেই একটি মজার বিষয় জানত যে-প্রাণীদের অনেকেই রাত্রে ঘুমাতে এক চোখ খোলা রাখে এবং আরেক চোখ বন্ধ করে রাখে। যেমন : ডলফিন, সিল, কিছু মাছ, বিভিন্ন ধরনের মাইগ্রেটরি পাখিদের মাঝে দেখা যায় তাদের অনেকে ঘুমানোর সময় এক চোখে ঘুমায়, আরেক চোখে উড়ে। পরীক্ষা করে দেখল ওই সময়ে প্রাণীগুলোর মস্তিষ্কের এক অংশ জেগে থাকে এবং আরেক অংশ ঘুমিয়ে থাকে। এমনকি পুকুরের হাঁসদের দেখবেন রাতেরবেলা পানিতে সাঁতার কাটছে, আবার অন্ধকারে এক চোখে ঘুমাচ্ছে।

মানুষ কোনো নতুন পরিবেশে গেলে মস্তিষ্কে কিছু স্টিমুলেশনের পরিবর্তন হয়। পরিবেশের এ উদ্দীপনা শুধু পরিবেশ থেকে হয় না। ভালো-মন্দ পরিবেশ যেমনই থাকুক, মস্তিষ্ক স্বয়ংক্রিয়ভাবে কিছু প্রতিক্রিয়া করে। এ প্রতিক্রিয়াতে আপনার আমার কোনো হাত নেই। না চাইলেও মস্তিষ্ক এমন আচরণ এবং প্রতিক্রিয়া করবে। কারণ হল-হাজার বছরের বিবর্তনে মানুষের মস্তিষ্ক ঠিক এমন করে গড়ে উঠেছে।

কিন্তু কী পরিবর্তন হয়, কেন পরিবর্তন হয়, কীভাবে হয় এবং পরিবর্তনের ফলাফল জানলেও প্রথম তিনটির উত্তর বিজ্ঞানীদের কাছে এতদিন ছিল না। বর্তমানে চিকিৎসক কিংবা ঘুম বিজ্ঞানীরা জানে নতুন পরিবেশে কেন আমাদের FNE হয়, কেন এবং কীভাবে আমাদের ঘুমের ব্যাঘাত ঘটে।

একটি ঘুম গবেষণা টিম এ নিয়ে কাজ করতে গিয়ে দেখতে পেল-নতুন পরিবেশে মানুষের মস্তিষ্কের অর্ধেক ঘুমায়, বাকি অর্ধেক জেগে থাকে। ফলে দীর্ঘ জার্নির পরেও হোটেলে প্রথম রাত যেন নির্ঘুম কাটে। পরদিন সকালবেলা দু’কাপ কফিতেও যেন ঘুমের ক্লান্তি দূর হয় না।

প্রথম রাতে নতুন পরিবেশে মস্তিষ্ক সতর্ক হয়ে ওঠে। মস্তিষ্ক নতুন পরিবেশে অজানা আশঙ্কায় থাকে। বিবর্তনে মানুষের মস্তিষ্ক নতুন পরিবেশে নতুন দৃশ্য, নতুন তাপমাত্রা, নতুন গন্ধ, সব সেন্সরিগুলোর মাধ্যমে সংগৃহীত স্বয়ংক্রিয় উপাত্ত আড়ালে মস্তিষ্ককে সতর্ক করে দেয়। ঘুমের ল্যাবে পরীক্ষা করে বিজ্ঞানীরা দেখেছেন যে, প্রথম রাতে বাম মস্তিষ্ক সতর্ক থাকে এবং ডান মস্তিষ্ক ঘুমায়। কারণ বাম মস্তিষ্কের কাজ বিপদের গন্ধ পাওয়া, আত্মরক্ষার কৌশল নির্ধারণ করা, প্ল্যান করা, সতর্কের সঙ্গে শরীরকে বিপদের হাত থেকে রক্ষা করে।

একদল ছাত্রের ওপর গবেষণায় ঘুম বিজ্ঞানীরা দেখল যে, প্রথম রাতে নতুন পরিবেশে তাদের বাম মস্তিষ্কে স্লো ওয়েব তরঙ্গ কম প্রবাহিত হয় এবং ডান মস্তিষ্কে এই প্রবাহ বেশি থাকে। আমরা যখন ঘুমাই, আমাদের গভীর ঘুমের সময় মস্তিষ্কের দুই অংশেই এই স্লো ওয়েব তরঙ্গ বেড়ে যায়। গবেষক দল আরও দেখতে পেল, প্রথম রাত্রিতে বাম মস্তিষ্কের অনেক অংশ যেমন একটিভ থাকে এবং স্লো ওয়েব কম হয়, পরদিন থেকে সেটি চলে যায় এবং দু-মস্তিষ্কের একই অবস্থা থাকে। ছাত্রদের সঙ্গে কথা বলে দু-রাতের ঘুমের পার্থক্য জেনে এবং মস্তিষ্ক স্ক্যানিং করে প্রাপ্ত ফলাফল তুলনা করে বিজ্ঞানীরা বুঝল যে, নতুন পরিবেশে বাম মস্তিষ্ক অজানা অচেনা পরিবেশের অনাকাক্সিক্ষত বিপদের হাত থেকে শরীরকে রক্ষা করতে, সেই সঙ্গে স্বয়ংক্রিয় এবং বিবর্তনমূলক সুবিধা পেতে এমন করে জেগে থাকে, কিন্তু ডান মস্তিষ্ক স্বাভাবিক নিয়মে ঘুমাতে চেষ্টা করে কিংবা ঘুমায়।

দুই মস্তিষ্ক প্রথম রাতে নতুন পরিবেশে সমানভাবে ঘুমাতে পারে না অথবা ঘুমায় না। এতে বিবর্তনের দৃষ্টিতে সুবিধা পেলেও শরীরের স্বাভাবিক প্রয়োজন এবং ক্লান্তি থেকে বের হতে পারে না। ফলে প্রথম রাত্রির পরদিন সকাল শারীরিক ক্লান্তি অবসাদ এবং নির্ঘুমতার ছাপ থাকলেও একদিন বা দুদিন পর মস্তিষ্কের আর এমন করার দরকার পড়ে না। তখন পুরো মস্তিষ্কই স্বাভাবিক নিয়মে ঘুম যায় এবং ঘুমের কোয়ালিটিও তখন ভালো হয়।

তাহলে এখন থেকে নতুন কোথাও প্রথম রাতে ঘুম না এলে উদ্বিগ্নতার কারণ নেই। ধরে নিতে হবে এটি মস্তিষ্কের একটি বিবর্তনমূলক ধারা এবং গঠন, যা মূলত শরীরের আত্মরক্ষার্থের প্রয়োজনে একটি সতর্কতামূলক ব্যবস্থা।

ডা. অপূর্ব চৌধুরী

লেখক : চিকিৎসক এবং লেখক, ইংল্যান্ড

https://www.jugantor.com/lifestyle

Sleep’s Role in Brain Health

·January 30, 2024

Summary: A new study reveals how sleep duration impacts brain health, specifically relating to stroke and dementia risks.

Analyzing brain images of nearly 40,000 middle-aged participants, the study found that both short and long sleep durations are associated with negative changes in brain structure.

These changes include higher presence and volume of white matter hyperintensities (WMH) and reduced fractional anisotropy, indicators of brain aging and dementia risk. The research underscores sleep as a key factor in maintaining brain health and highlights middle age as a critical period for sleep habit adjustments.

Key Facts:

1. Inadequate sleep, both too little and too much, is linked to increased WMH presence, larger WMH volume, and lower fractional anisotropy.

2. These brain changes are associated with higher risks of stroke and dementia.

3. The study emphasizes the importance of optimal sleep (7–9 hours) for brain health in middle-aged individuals.

Source: Yale

Getting either too much or too little sleep is associated with changes in the brain that have been shown to increase the risk of stroke and dementia later in life, a recent study finds.

The research is published in the Journal of the American Heart Association.

“Conditions like stroke or dementia are the end-stage result of a long process that ends tragically,” says Santiago Clocchiatti-Tuozzo, MD, T32 postdoctoral fellow in the Falcone lab at Yale School of Medicine and first author of the study. “We want to learn how to prevent these processes before they happen.”

Long sleep (averaging more than 9 hours per night) was associated with lower fractional anisotropy and with larger WMH volume, but not with risk of WMH presence. Credit: Neuroscience News

In one of the largest neuroimaging studies of its kind to date, the Yale team examined brain images of close to 40,000 healthy, middle-aged participants to evaluate how sleeping habits might impact two measures of brain health: white matter hyperintensities (WMH), which are lesions on the brain indicating brain aging, and fractional anisotropy, which measures the uniformity of water diffusion along nerve axons. More WMH, larger WMH, and lower fractional anisotropy are associated with increased risk of stroke and dementia.

Researchers found that compared with optimal sleep (7–9 hours per night), participants with short sleep had higher risk of WMH presence, larger WMH volume where WMH was present, and lower fractional anisotropy. Long sleep (averaging more than 9 hours per night) was associated with lower fractional anisotropy and with larger WMH volume, but not with risk of WMH presence.

“These findings add to the mounting evidence that sleep is a prime pillar of brain health,” says Clocchiatti-Tuozzo. “It also provides evidence toward helping us understand how sleep and sleep duration can be a modifiable risk factor for brain health later in life.”

Researchers say the study highlights middle age as an important time to adjust our sleeping habits to support brain health.

“Sleep is starting to become a trending topic,” Clocchiatti-Tuozzo says. “We hope this study and others can offer insight into how we can modify sleep in patients to improve brain health in years to come.”

Cyprien Rivier, Daniela Renedo, Victor Torres Lopez, Jacqueline Geer, Brienne Miner, Henry Yaggi, Adam de Havenon, Seyedmedhi Payabvash, Kevin Sheth, Thomas Gill and Guido Falcone were co-authors of the study. https://neurosciencenews.com/

Suboptimal Sleep Duration Is Associated With Poorer Neuroimaging Brain Health Profiles in Middle‐Aged Individuals Without Stroke or Dementia

Abstract

Background

The American Heart Association's Life's Simple 7, a public health construct capturing key determinants of cardiovascular health, became the Life's Essential 8 after the addition of sleep duration.

Methods and Results

The authors conducted a prospective magnetic resonance neuroimaging study in middle‐aged individuals without stroke or dementia enrolled in the UK Biobank. Self‐reported sleep duration was categorized as short (<7 hours), optimal (7–<9 hours), or long (≥9 hours). Evaluated neuroimaging markers included the presence of white matter hyperintensities (WMHs), volume of WMH, and fractional anisotropy, with the latter evaluated as the average of 48 white matter tracts. Multivariable logistic and linear regression models were used to test for an association between sleep duration and these neuroimaging markers. The authors evaluated 39 771 middle‐aged individuals. Of these, 28 912 (72.7%) had optimal, 8468 (21.3%) had short, and 2391 (6%) had long sleep duration. Compared with optimal sleep, short sleep was associated with higher risk of WMH presence (odds ratio, 1.11 [95% CI, 1.05–1.18]; P<0.001), larger WMH volume (beta=0.06 [95% CI, 0.04–0.08]; P<0.001), and worse fractional anisotropy profiles (beta=−0.04 [95% CI, −0.06 to −0.02]; P=0.001). Compared with optimal sleep, long sleep duration was associated with larger WMH volume (beta=0.04 [95% CI, 0.01–0.08]; P=0.02) and worse fractional anisotropy profiles (beta=−0.06 [95% CI, −0.1 to −0.02]; P=0.002), but not with WMH presence (P=0.6).

Conclusions

Among middle‐aged adults without stroke or dementia, suboptimal sleep duration is associated with poorer neuroimaging brain health profiles. Because these neuroimaging markers precede stroke and dementia by several years, these findings are consistent with other findings evaluating early interventions to improve this modifiable risk factor. https://www.ahajournals.org/doi/10.1161/JAHA.123.031514

Boosting Learning With the Power of Passive Exposure

·January 27, 2024

Summary: Researchers discovered in mice that passive exposure, alongside active training, can significantly enhance the learning process. This study demonstrates how passive exposure to stimuli like sounds or languages helps the brain to form foundational representations, making active learning more efficient.

The findings, which align with prior research in humans, suggest that combining low-effort passive exposure with active training can lead to quicker mastery of new skills, such as learning a musical instrument or a foreign language.

Key Facts:

1. Mice exposed to sounds passively, in addition to active training, learned to associate sounds with rewards more quickly.

2. Artificial neural network simulations indicate that passive exposure creates a foundational representation of stimuli in the brain.

3. The study’s insights align with human research, suggesting a combined approach of passive exposure and active training could enhance complex skill learning.

Source: University of Oregon

Learning a new skill takes deliberate practice over time, but passive exposure to the subject matter at hand can help speed up the process, new University of Oregon research in mice suggests.

The finding, which builds on past research in humans, shows how passive exposure can be a valuable tool for learning. It helps explain how watching movies in a foreign language might supplement grammar drills and vocabulary flashcards, or how listening to recordings of a professional playing piano concertos could help budding musicians improve their own craft.

https://neurosciencenews.com/passive-exposure-learning-25531/

·January 27, 2024

Key Facts:

1. Mice exposed to sounds passively, in addition to active training, learned to associate sounds with rewards more quickly.

2. Artificial neural network simulations indicate that passive exposure creates a foundational representation of stimuli in the brain.

3. The study’s insights align with human research, suggesting a combined approach of passive exposure and active training could enhance complex skill learning.

Source: University of Oregon

Learning a new skill takes deliberate practice over time, but passive exposure to the subject matter at hand can help speed up the process, new University of Oregon research in mice suggests.

The study gives additional insight into the possible brain mechanisms behind the effect, helping scientists understand just why passive exposure is so powerful, said James Murray, a UO neuroscientist who led the study alongside fellow UO neuroscientist Santiago Jaramillo, both part of the College of Arts and Sciences.

Because it’s much easier to study what’s happening inside the brain of a rodent than a human, “studying how both active training and passive exposure affect learning in mice opens up exciting possibilities for investigating the neural mechanisms underlying the interplay between them,” Murray added.

The researchers describe their findings in a paper published in the journal eLife.

To study how mice learn, researchers trained the animals to reach for a reward in a particular spot in response to tones that slid up or down in pitch. All of the mice were put through an active training protocol, in which they got feedback on their performance so they knew whether they made the right choice. Some of the mice also got passive exposure, where they heard the sounds while they weren’t engaged in the task.

The mice who were passively exposed to the sounds in addition to being actively trained learned how to select the reward location more quickly, the researchers showed. It didn’t seem to matter whether the passive exposure happened at the beginning of training or was interspersed in small chunks throughout the active training sessions.

Then, to better understand how the learning might be happening in the brain, the researchers trained and tested different artificial neural networks on a simulated version of the learning task. Neural networks, a kind of machine learning algorithm, process information in a way that mimics the way the brain processes information.

Artificial neurons represent real neurons, and learning takes place by modifying the strengths of the connections between those neurons. They’re not a direct replica for the brain, but they can be used to generate hypotheses that can then be tested experimentally.

The modeling suggests that passive exposure to a stimulus lays the groundwork in the brain, creating a hidden representation of that stimulus that captures its most prominent features, like making a pencil outline before diving into a detailed painting. Then, during active learning, the brain links the stimulus to particular behaviors. With passive exposure, the brain is primed to make those connections more quickly.

In the future, the team hopes to record brain activity in mice during a similar learning task, to see if their predictions play out.

While the research was done using a simple task in mice, the findings might also have implications for more complex learning in humans, the researchers suggest. Study co-author Melissa Baese-Berk, a former UO linguist now at the University of Chicago, has previously published studies showing how passive exposure can help adult humans better learn to understand new speech sounds.

“Alongside the previous work on humans from Melissa and her collaborators, our results suggest that, in mice and in humans, a given performance threshold can be achieved with relatively less effort by combining low-effort passive exposure with active training,” Murray said.

“This insight could be helpful for humans learning an instrument or a second language, though more work will be needed to better understand how this applies to more complex tasks and how to optimize training schedules that combine passive exposure with active training.”

স্ট্রোকে ব্রেনের ভেতরের রক্তনালির মধ্যে এক বা একাধিক রক্তনালি ব্লক হয়ে যায় অথবা ছিঁড়ে যায়। ব্রেনের একেকটি অংশ শরীরের একেক অংশকে নিয়ন্ত্রণ করে। স্ট্রোকের ফলে ওই রক্তনালি ব্রেনের যে অংশে রক্ত সরবরাহ করে সচল রাখত, সে অংশ তার কার্যক্ষমতা হারায়। ফলে শরীরের ওই অংশের কার্যক্রম বন্ধ হয়ে যায় বা কমে যায়। বেশিভাগ ক্ষেত্রে ব্রেনের যে কোনো একপাশের রক্তনালি ব্লক হয়ে বা ছিঁড়ে গিয়ে স্ট্রোক হয়। সেজন্য স্ট্রোকের লক্ষণও সাধারণত আমাদের শরীরের একপাশে দেখা দেয়।

* স্ট্রোকের লক্ষণ

হঠাৎ করে শরীরের এক পাশের হাত-পা অবশ হয়ে যাওয়া, অথবা আলাদাভাবে শুধু একহাত বা পা অবশ হওয়া, কথা জড়িয়ে যাওয়া, মুখ বাঁকা হওয়া, খাবার গিলতে অসুবিধা হওয়া, চোখে ঠিকমতো দেখতে না পারা-ইত্যাদিও স্ট্রোকের লক্ষণ। একজন সুস্থ সবল ব্যক্তির যখন হঠাৎ এসব সমস্যা দেখা দেবে, তখনই ধরে নিতে হবে তিনি স্ট্রোকে আক্রান্ত হয়েছেন। এসব লক্ষণ দেখে নিকটজন স্ট্রোকে আক্রান্ত হয়েছেন সন্দেহ করলেই আমাদের উচিত হবে, রোগীকে তৎক্ষণাৎ নিকটস্থ হাসপাতালে, সম্ভব হলে সব সুযোগ-সুবিধা সম্পন্ন হাসপাতালে নিয়ে যাওয়া। যেখানে অতি দ্রুত ব্রেনের ইমেজিংসহ প্রয়োজনীয় পরীক্ষা-নিরীক্ষা করে স্ট্রোকের আধুনিক চিকিৎসা শুরু করা সম্ভব। এসব রোগীর ক্ষেত্রে স্ট্রোক পরবর্তী প্রতিটি মুহূর্ত মূল্যবান। লক্ষণ শুরু হওয়ার পর যত তাড়াতাড়ি রোগীর চিকিৎসা শুরু করা যায়, ব্রেনের ক্ষতির হার তত কম হয়। স্ট্রোকের কারণে রোগীর শরীরে ঘটে যাওয়া শারীরিক সমস্যার উন্নতির হারও দ্রুত হয়।

* চিকিৎসা

বর্তমানে স্ট্রোকের আধুনিক চিকিৎসা হচ্ছে- থ্রম্বোলাইসিস। যেখানে স্ট্রোক হওয়ার সময় থেকে পরবর্তী চার থেকে সাড়ে চার ঘণ্টার মধ্যে সিটি স্ক্যান/এমআরআই-সহ প্রয়োজনীয় পরীক্ষা-নিরীক্ষার পর রোগীর অবস্থা এনালাইসিস করা হয়। রোগী যদি থ্রম্বোলাইসিস চিকিৎসার শর্তাবলী পূরণ করে, তবে সংশ্লিষ্ট রোগীকে স্ট্রোকের এই আধুনিক চিকিৎসা দেওয়া হয়। এ চিকিৎসায় রেজাল্ট খুবই ভালো। রোগী আরও খারাপ তো হয়-ই না, বরং এক-দুদিনের মধ্যে প্রায় সম্পূর্ণ সুস্থতা লাভ করে। নিঃসন্দেহে এটি বর্তমান চিকিৎসা বিজ্ঞানের একটি আশীর্বাদ। বাংলাদেশের বেশ কয়েকটি টারশিয়ারি লেভেলের হাসপাতালে স্ট্রোকের এ সমন্বিত চিকিৎসা চালু আছে। স্ট্রোকের ক্ষেত্রে প্রতিটি মুহূর্ত মূল্যবান। তবে সবার আগে মনে রাখতে হবে Prevention is better than cure. অর্থাৎ আমাদের চেষ্টা থাকবে স্ট্রোক যাতে না হয়।

* প্রতিরোধ

যাদের ডায়াবেটিস, হাই ব্লাড প্রেসার, হার্টের অসুখ ও রক্তে চর্বি বেশি, তাদের স্ট্রোকে আক্রান্ত হওয়ার আশঙ্কা বেশি। সুতরাং যাদের এসব রোগ রয়েছে, স্ট্রোকের হাত থেকে বাঁচতে তাদের উচিত হবে এসব রোগ কঠোরভাবে কন্ট্রোল করা। স্ট্রোকের সঙ্গে সংশ্লিষ্ট এসব রোগের উপযুক্ত কন্ট্রোল ছাড়াও কিছু সচেতনতা এবং সতর্কতাও স্ট্রোকের হাত থেকে আমাদের বাঁচাতে পারে। ধূমপান, শারীরিক নিষ্ক্রিয়তা অর্থাৎ কম কায়িক পরিশ্রম করা, অস্বাস্থ্যকর খাবার অর্থাৎ সুষম খাবার না খাওয়া, অতিরিক্ত ওজন বৃদ্ধি ইত্যাদিও স্ট্রোকের ঝুঁকি বাড়িয়ে দেয়। স্ট্রোক প্রতিরোধে এসব ব্যাপারেও আমাদের সতর্ক থাকতে হবে।

* শীতে কি স্ট্রোক বাড়ে

শীতের সঙ্গে স্ট্রোকের সম্পর্ক আছে। অন্যান্য ডাক্তারি কারণ ছাড়াও এর সাধারণ ব্যাখ্যা হলো-শীতে শরীরের তাপমাত্রা কমে আমাদের রক্তনালি সংকুচিত হয়ে প্রেশার বেড়ে যায়। আর প্রেশার বেড়ে যাওয়ার ফলে শীতকালে ব্রেনের রক্তনালি ছিঁড়ে হেমোরেজিক স্ট্রোকের হার বেশি হয়। সেজন্য শীতকালে স্ট্রোকের হাত থেকে বাঁচতে অন্যান্য সতর্কতার সঙ্গে নিয়মিত প্রেশার চেক করাও অত্যাবশ্যক। তাৎক্ষণিক রেজাল্টের ভিত্তিতে হাই প্রেসারের রোগীদের ওষুধও সময়ে সময়ে এডজাস্ট করতে হয়।

লেখক: কনসালটেন্ট, নিউরোমেডিসিন, আজগর আলী হাসপাতাল, ঢাকা।

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Brain Network for Thirst and Salt Regulation Revealed

·January 26, 2024

Summary: Researchers made a significant breakthrough in understanding how the brain regulates thirst and salt appetite. Their study utilized optogenetic and chemogenetic techniques on mice to explore the parabrachial nucleus (PBN), a key brain region in processing ingestion signals.

They identified two specific neuron populations in the lateral PBN that respond to water and salt intake, revealing how these neurons help modulate consumption behavior and prevent excessive intake. This research provides crucial insights into brain mechanisms controlling fluid balance and related disorders.

Key Facts:

1. Two distinct neuron populations in the lateral PBN respond to water and salt intake, regulating thirst and salt appetite.

2. Optogenetic activation of these neurons reduces water and salt consumption, even in deprived conditions.

3. The findings offer significant insights into neurological control of fluid intake and have implications for understanding disorders caused by excessive water and salt consumption.

Source: Tokyo Institute of Technology

Staying hydrated and consuming appropriate amounts of salt is essential for the survival of terrestrial animals, including humans. The human brain has several regions constituting neural circuits that regulate thirst and salt appetite, in intriguing ways.

Previous studies suggested that water or salt ingestion quickly suppresses thirst and salt appetite before the digestive system absorbs the ingested substances, indicating the presence of sensing and feedback mechanisms in digestive organs that help real-time thirst and salt appetite modulation in response to drinking and feeding. Unfortunately, despite extensive research on this subject, the details of these underlying mechanisms remained elusive.

During the experiments, the researchers offered the mice—either in regular or water- or salt-depleted conditions—water and/or salt water, and monitored neural activities along with the corresponding drinking behaviors. Credit: Neuroscience News

To shed light on this matter, a research team from Japan has recently conducted an in-depth study on the parabrachial nucleus (PBN), the brain’s relay center for ingestion signals coming from digestive organs.

Their latest paper, whose first author is Assistant Professor Takashi Matsuda from Tokyo Institute of Technology, was published in Cell Reports on January 23, 2024.

The researchers conducted a series of in vivo experiments using genetically engineered mice. They introduced optogenetic (and chemogenetic) modifications and in vivo calcium imaging techniques into these mice, enabling them to visualize and control the activation or inhibition of specific neurons in the lateral PBN (LPBN) using light (and chemicals).

In this way, the team identified two distinct subpopulations of cholecystokinin mRNA-positive neurons in the LPBN, which underwent activation during water and salt intake. The neuronal population that responds to water intake projects from the LPBN to the median preoptic nucleus (MnPO), whereas the one that responds to salt intake projects to the ventral bed nucleus of the stria terminalis (vBNST).

Interestingly, if the researchers artificially activated these neuronal populations through optogenetic (genetic control using light) experiments, the mice drank substantially less water and ingested less salt, even if they were previously water- or salt-deprived. Similarly, when the researchers chemically inhibited these neurons, the mice consumed more water and salt than usual.

Therefore, these neuronal populations in the LPBN are involved in feedback mechanisms that reduce thirst and salt appetite upon water or salt ingestion, possibly helping prevent excessive water or salt intake.

These results, alongside their previous neurological studies, also reveal that MnPO and vBNST are the control centers for thirst and salt appetite, integrating promotion and suppression signals from several other brain regions.

“Understanding brain mechanisms controlling water and salt intake behaviors is not only a significant discovery in the fields of neuroscience and physiology, but also contributes valuable insights to understand the mechanisms underlying diseases induced by excessive water and salt intake, such as water intoxication, polydipsia, and salt-sensitive hypertension,” remarks Dr. Matsuda.

Prof. Noda mentions, “Many neural mechanisms governing fluid homeostasis remain undiscovered. We still need to unravel how the signals for inducing and suppressing water and salt intake, accumulated in the MnPO and vBNST, are integrated and function to control intake behaviors.” https://neurosciencenews.com/hydration-salt-neuroscience-25528/

Nasal Lymphatic Network Crucial for Brain CSF Drainage

https://neurosciencenews.com

·January 26, 2024

Summary: Researchers discovered a crucial network of lymphatic vessels at the back of the nose, which significantly contributes to draining cerebrospinal fluid (CSF) from the brain. This study reveals a previously unknown CSF outflow route, offering insights into neurodegenerative conditions.

The research team used transgenic mice with lymphatic markers and advanced imaging to uncover this network, which connects to deep cervical lymph nodes. Their findings indicate potential therapeutic targets for enhancing CSF drainage, especially in age-related neurodegenerative diseases.

Key Facts:

1. The newly discovered nasopharyngeal lymphatic plexus is a major hub for CSF drainage from the brain.

2. The study suggests that activating cervical lymphatics could improve CSF outflow, offering a new therapeutic approach for neurodegenerative diseases.

3. The research team plans to validate these findings in primates, aiming to advance treatments for conditions like Alzheimer’s disease.

Source: Institute for Basic Science

In a groundbreaking study published in Nature, South Korean researchers led by Director KOH Gou Young of the Center for Vascular Research within the Institute for Basic Science (IBS) have uncovered a distinctive network of lymphatic vessels at the back of the nose that plays a critical role in draining cerebrospinal fluid (CSF) from the brain.

The study, sheds light on a previously unknown route for CSF outflow, potentially unlocking new avenues for understanding and treating neurodegenerative conditions.

In our brains, waste products generated as byproducts of metabolic activity are expelled through cerebrospinal fluid (CSF). Accumulation of waste in the brain, if not properly expelled, can damage nerve cells, leading to impaired cognitive function, dementia, and other neurodegenerative brain disorders.

Hence, the regulation of CSF production, circulation, and drainage has long been a focus of scientific attention, especially in relation to age-related conditions like Alzheimer’s disease and other neurodegenerative diseases.

The brain produces around 500 mL of this fluid per day, which is drained from the subarachnoid space. Among the known drainage routes are lymphatic vessels around the cranial nerves and the upper region of the nasal cavity.

Despite well-documented evidence of lymphatics aiding CSF clearance, identifying the exact anatomical connections between the subarachnoid space and extracranial lymphatics has posed a challenge due to their extremely complex structure.

Koh’s team tackled this problem using transgenic mice with lymphatic fluorescent markers, microsurgeries, and advanced imaging techniques. Their efforts revealed a detailed network of lymphatic vessels at the back of the nose that serves as a major hub for CSF outflow to deep cervical lymph nodes in the neck. These lymphatics were found to have distinct features, including unusually shaped valves and short lymphangions.

Lead researcher JIN Hokyung highlighted, “Our study identified the nasopharyngeal lymphatic plexus as a hub for CSF outflow. CSF from specific cranial regions drained through these lymphatics to deep cervical lymph nodes in the neck. This discovery could have significant implications for understanding and treating conditions related to impaired CSF drainage.”

The study also demonstrated that pharmacological activation of the deep cervical lymphatics enhanced CSF drainage in mice.

The researchers were able to successfully modulate cervical lymphatics using phenylephrine (which activates α1-adrenergic receptors, causing smooth-muscle contraction) or sodium nitroprusside (which releases nitric oxide, inducing muscle relaxation and vessel dilation).

Importantly, this feature was preserved during aging, even when the nasopharyngeal lymphatic plexus had shrunk and was functionally impaired.

YOON Jin-Hui, the co-first author of this study, notes, “The deep cervical lymphatics, which remain intact with aging, offer a potential target for therapeutic interventions aimed at improving CSF outflow in individuals with compromised brain health.”

This endeavor was not without its own challenges, however. Deep anesthesia and removal of neck musculature were required to expose the lymphatics in the mice.

These delicate procedures themselves had problems altering the physiological dynamics of CSF drainage because cerebral blood flow and blood pulsing through the vasculature contribute to CSF circulation, which in turn influences CSF outflow.

Also, while the imaging techniques used were informative, researchers believe more advanced methods for imaging live animals (such as synchrotron X-ray imaging) may reveal more features of the dynamics of CSF drainage under physiological conditions.

Director KOH Gou Young of the Center for Vascular Research stated, “We plan to verify all the findings from the mice in primates, including monkeys and humans. We aim to investigate in a reliable animal model whether activating the cervical lymphatic vessels through pharmacological or mechanical means can prevent the exacerbation of Alzheimer’s disease progression by improving CSF clearance.”

https://neurosciencenews.com/nasal-lymphatic-network-csf-drainage-25530/

Brain Network for Thirst and Salt Regulation Revealed

Handwriting Boosts Brain Connectivity and Learning

Summary: Handwriting, compared to typing, results in more complex brain connectivity patterns, enhancing learning and memory. This study used EEG data from 36 students to compare brain activity while writing by hand and typing.

Handwriting, whether in cursive on a touchscreen or traditional pen and paper, activated extensive brain regions, vital for memory and learning. These findings highlight the importance of balancing traditional handwriting instruction with digital literacy in educational settings.

Key Facts:

1. Handwriting activates more complex brain connectivity than typing, beneficial for learning and memory.

2. The study used high-density EEGs to measure brain activity, demonstrating the unique cognitive engagement of handwriting.

3. The results advocate for maintaining handwriting instruction in schools alongside digital literacy.

Source: Frontiers

As digital devices progressively replace pen and paper, taking notes by hand is becoming increasingly uncommon in schools and universities. Using a keyboard is recommended because it’s often faster than writing by hand. However, the latter has been found to improve spelling accuracy and memory recall.

To find out if the process of forming letters by hand resulted in greater brain connectivity, researchers in Norway now investigated the underlying neural networks involved in both modes of writing.

“We show that when writing by hand, brain connectivity patterns are far more elaborate than when typewriting on a keyboard,” said Prof Audrey van der Meer, a brain researcher at the Norwegian University of Science and Technology and co-author of the study published in Frontiers in Psychology.

“Such widespread brain connectivity is known to be crucial for memory formation and for encoding new information and, therefore, is beneficial for learning.”

The pen is mightier than the (key)board

The researchers collected EEG data from 36 university students who were repeatedly prompted to either write or type a word that appeared on a screen. When writing, they used a digital pen to write in cursive directly on a touchscreen. When typing they used a single finger to press keys on a keyboard.

High-density EEGs, which measure electrical activity in the brain using 256 small sensors sewn in a net and placed over the head, were recorded for five seconds for every prompt.

Connectivity of different brain regions increased when participants wrote by hand, but not when they typed.

“Our findings suggest that visual and movement information obtained through precisely controlled hand movements when using a pen contribute extensively to the brain’s connectivity patterns that promote learning,” van der Meer said.

Movement for memory

Although the participants used digital pens for handwriting, the researchers said that the results are expected to be the same when using a real pen on paper.

“We have shown that the differences in brain activity are related to the careful forming of the letters when writing by hand while making more use of the senses,” van der Meer explained.

Since it is the movement of the fingers carried out when forming letters that promotes brain connectivity, writing in print is also expected to have similar benefits for learning as cursive writing.

On the contrary, the simple movement of hitting a key with the same finger repeatedly is less stimulating for the brain.

“This also explains why children who have learned to write and read on a tablet, can have difficulty differentiating between letters that are mirror images of each other, such as ‘b’ and ‘d’. They literally haven’t felt with their bodies what it feels like to produce those letters,” van der Meer said.

A balancing act

Their findings demonstrate the need to give students the opportunity to use pens, rather than having them type during class, the researchers said. Guidelines to ensure that students receive at least a minimum of handwriting instruction could be an adequate step. For example, cursive writing training has been re-implemented in many US states at the beginning of the year.

At the same time, it is also important to keep up with continuously developing technological advances, they cautioned. This includes awareness of what way of writing offers more advantages under which circumstances.

“There is some evidence that students learn more and remember better when taking handwritten lecture notes, while using a computer with a keyboard may be more practical when writing a long text or essay,” van der Meer concluded.

Stressful Life Events Linked to Poor Biological Health

Summary: Researchers have found a strong link between stressful life events and deteriorating biological health. Analyzing blood concentrations of four key biomarkers in over 4,900 participants, the study reveals how stress disrupts the immune, nervous, and endocrine systems’ communication, increasing the risk of illnesses like cardiovascular disease and depression.

Chronic stressors like financial strain were particularly detrimental, with those experiencing such stress 59% more likely to be in the high-risk group for health issues. This groundbreaking research underscores the profound impact of stress on our biological systems, regardless of genetic predisposition.

Key Facts:

1. Stressful events, including financial strain, significantly disrupt the healthy interaction of the immune, nervous, and endocrine systems.

2. Individuals exposed to stress were 61% more likely to be in a high-risk health group, with each additional stressor increasing this likelihood by 19%.

3. The study establishes that chronic stress can lead to poor biological health, independent of genetic factors.

Source: UCL

People who experience stressful life events or circumstances are more likely to have worse biological health, as indicated by biomarkers involved in the interaction between our immune, nervous and endocrine systems, according to a new study by UCL researchers.

The study, published in the journal Brain, Behavior and Immunity, found that not only major stressful experiences such as bereavement but chronic challenges such as financial strain were detrimental to the healthy interaction of these systems.

The researchers then looked at how earlier exposure to stressful circumstances might affect people’s likelihood of being in the high-risk group. Credit: Neuroscience News

Communication between our immune, nervous, and endocrine systems is necessary to maintain good health. Disruption of these processes is linked to a wide range of mental and physical illnesses, from cardiovascular disease to depression and schizophrenia.

When a threat like stress occurs, signals between the immune, nervous, and endocrine systems are activated and spur physiological and behavioural changes.

In this new study, the researchers analysed blood concentrations of four biomarkers in 4,934 people aged 50 and over who were participants of the English Longitudinal Study of Ageing. Two of these were proteins involved in the innate immune response to inflammation (C-reactive protein and fibrinogen), and two were hormones involved in the physiology of the stress response (cortisol and IGF-1).

The team used a sophisticated statistical technique, latent profile analysis, to identify clusters of biomarker activity. Three groups were identified and labelled as low risk to health, moderate risk, and high risk. The researchers then looked at how earlier exposure to stressful circumstances might affect people’s likelihood of being in the high-risk group.

They found that exposure to stressful circumstances overall, ranging from being an informal carer to experiencing a bereavement or divorce in the last two years, was linked to a 61% increase in likelihood of belonging to the high-risk group four years later.

Separately, the effect was also cumulative, as the likelihood of belonging to the high-risk group increased by 19% for each stressor experienced, for those who experienced more than one stress-inducing circumstance.

People who reported only financial strain – the perception that they may not have enough financial resources to meet their future needs – were 59% more likely, four years later, to belong to the high-risk group.

Lead author, PhD candidate Odessa S. Hamilton (UCL Institute of Epidemiology & Health Care), said: “When the immune and neuroendocrine systems function well together, homeostasis is maintained and health is preserved. But chronic stress can disrupt this biological exchange and lead to disease.

“We found that financial stress was most detrimental to biological health, although more research is needed to establish this for certain. This may be because this form of stress can invade many aspects of our lives, leading to family conflict, social exclusion, and even hunger or homelessness.”

Experiencing stress over a prolonged period of time can disturb the communication between the immune and neuroendocrine systems. That is because our response to stress is similar to our response to sickness, activating some of the same pathways (for instance, both responses trigger the production of immune system signals called pro-inflammatory cytokines).

The researchers also looked at genetic variants previously found to influence our immune-neuroendocrine response and found that the association between stressful life circumstances and belonging to the high-risk group four years later remained true irrespective of genetic predisposition.

Funding: The research was supported by the National Institute on Aging, the UK’s National Institute for Health and Care Research (NIHR), the Economic and Social Research Council (ESRC), the Biotechnology and Biological Sciences Research Council (BBSRC) and UCL. https://neurosciencenews.com/financial-stress-health-25511/

Neural Connectivity: A Universal Network Phenomenon

Science is not only compatible with spirituality, it is a profound source of spirituality.(Calr sagan বিজ্ঞান শুধুমাত্র আধ্যাত্মিকতার সাথে সামঞ্জস্যপূর্ণ নয়, এটি আধ্যাত্মিকতার একটি গভীর উৎস।

Electrophysiology Featured Neuroscience

·January 17, 2024

Summary: A groundbreaking study by physicists and neuroscientists reveals that the connectivity among neurons stems from universal networking principles, not just biological specifics.

Analyzing various model organisms, researchers found a consistent “heavy-tailed” distribution of neural connections, guided by Hebbian dynamics, indicating that neuron connectivity relies on general network organization.

This discovery, transcending biology, potentially applies to non-biological networks like social interactions, offering insights into the fundamental nature of networking.

Key Facts:

1. The study analyzed neuron connectivity in diverse organisms, including fruit flies, roundworms, and mice, finding a universal “heavy-tailed” pattern.

2. Researchers developed a model based on Hebbian dynamics, successfully mirroring the observed neural connectivity across different species.

3. The findings suggest that neuron connections are governed by universal networking principles, potentially applicable to various networks beyond the brain.

Source: University of Chicago

A new study by physicists and neuroscientists from the University of Chicago, Harvard and Yale describes how connectivity among neurons comes about through general principles of networking and self-organization, rather than the biological features of an individual organism.

The research, published on January 17, 2024 in Nature Physics, accurately describes neuronal connectivity in a variety of model organisms and could apply to non-biological networks like social interactions as well.

While the vast number of connections may seem random, networks of brain cells tend to be dominated by a small number of connections that are much stronger than most. Credit: Neuroscience News

“When you’re building simple models to explain biological data, you expect to get a good rough cut that fits some but not all scenarios,” said Stephanie Palmer, PhD, Associate Professor of Physics and Organismal Biology and Anatomy at UChicago and senior author of the paper.

“You don’t expect it to work as well when you dig into the minutiae, but when we did that here, it ended up explaining things in a way that was really satisfying.”

Understanding how neurons connect

Neurons form an intricate web of connections between synapses to communicate and interact with each other. While the vast number of connections may seem random, networks of brain cells tend to be dominated by a small number of connections that are much stronger than most.

This “heavy-tailed” distribution of connections (so-called because of the way it looks when plotted on a graph) forms the backbone of circuitry that allows organisms to think, learn, communicate and move. Despite the importance of these strong connections, scientists were unsure if this heavy-tailed pattern arises because of biological processes specific to different organisms, or due to basic principles of network organization.

To answer these questions, Palmer and Christopher Lynn, PhD, Assistant Professor of Physics at Yale University, and Caroline Holmes, PhD, a postdoctoral researcher at Harvard University, analyzed connectomes, or maps of brain cell connections. The connectome data came from several different classic lab animals, including fruit flies, roundworms, marine worms and the mouse retina.

To understand how neurons form connections to one another, they developed a model based on Hebbian dynamics, a term coined by Canadian psychologist Donald Hebb in 1949 that essentially says, “neurons that fire together, wire together.” This means the more two neurons activate together, the stronger their connection becomes.

Across the board, the researchers found these Hebbian dynamics produce “heavy-tailed” connection strengths just like they saw in the different organisms. The results indicate that this kind of organization arises from general principles of networking, rather than something specific to the biology of fruit flies, mice, or worms.

The model also provided an unexpected explanation for another networking phenomenon called clustering, which describes the tendency of cells to link with other cells via connections they share.

A good example of clustering occurs in social situations. If one person introduces a friend to a third person, those two people are more likely to become friends with them than if they met separately.

“These are mechanisms that everybody agrees are fundamentally going to happen in neuroscience,” Holmes said. “But we see here that if you treat the data carefully and quantitatively, it can give rise to all of these different effects in clustering and distributions, and then you see those things across all of these different organisms.”

Accounting for randomness

As Palmer pointed out, though, biology doesn’t always fit a neat and tidy explanation, and there is still plenty of randomness and noise involved in brain circuits. Neurons sometimes disconnect and rewire with each other — weak connections are pruned, and stronger connections can be formed elsewhere.

This randomness provides a check on the kind of Hebbian organization the researchers found in this data, without which strong connections would grow to dominate the network.

The researchers tweaked their model to account for randomness, which improved its accuracy.

“Without that noise aspect, the model would fail,” Lynn said. “It wouldn’t produce anything that worked, which was surprising to us. It turns out you actually need to balance the Hebbian snowball effect with the randomness to get everything to look like real brains.”

Since these rules arise from general networking principles, the team hopes they can extend this work beyond the brain.

“That’s another cool aspect of this work: the way the science got done,” Palmer said. “The folks on this team have a huge diversity of knowledge, from theoretical physics and big data analysis to biochemical and evolutionary networks. We were focused on the brain here, but now we can talk about other types of networks in future work.”

Funding: The study, “Heavy–tailed neuronal connectivity arises from Hebbian self–organization,” was supported by the National Science Foundation, through the Center for the Physics of Biological Function (PHY–1734030) and a Graduate Research Fellowship (C.M.H.); by the James S. McDonnell Foundation through a Postdoctoral Fellowship Award (C.W.L.); and by the National Institutes of Health BRAIN initiative (R01EB026943).

https://neurosciencenews.com/neural-netowrk-connectivity-25472/

Violent Video Games Do Not Diminish Empathy

·January 17, 2024

Summary: A recent study challenges the notion that violent video games diminish empathy. Adult subjects, new to such games, participated in an experiment where they played a violent version of Grand Theft Auto V. Their empathic responses were measured before and after the gaming sessions. Surprisingly, the study found no significant impact on empathy or related brain activity.

Key Facts:

1. The study involved 89 adult males with minimal exposure to violent video games, ensuring unbiased results.

2. Participants played a violent version of Grand Theft Auto V, but this had no discernible effect on their empathetic responses or brain activity.

3. The study cautions against conclusive claims about the harmlessness of violent video games, emphasizing the need for careful interpretation and further research.

Source: University of Vienna

Neuroscientists from the University of Vienna and the Karolinska Institute in Stockholm have investigated whether playing violent video games leads to a reduction in human empathy.

To do this, they had adult test subjects play a violent video game repeatedly over the course of an experiment lasting several weeks. Before and after, their empathic responses to the pain of another person were measured. It was found that the violent video game had no discernible effect on empathy and underlying brain activity.

These results have now been published in the renowned journal eLife.

Does that mean that concerns about violence in video games are unfounded? Credit: Neuroscience News

Video games have become an integral part of the everyday life of many children and adults. Many of the most popular video games contain explicit depictions of extreme violence.

Therefore, concerns have been raised that these games may blunt the empathy of their players and could therefore lower the inhibition threshold for real violence. An international research team led by Viennese neuroscientists Claus Lamm and Lukas Lengersdorff has now investigated whether this is actually the case.

The Austrian and Swedish researchers invited a total of 89 adult male subjects to take part in the study. A key selection criterion was that the subjects had had little or no previous contact with violent video games. This ensured that the results were not influenced by different experiences with these games.

In a first experimental study, the baseline level of empathy of the test subjects was assessed. Brain scans were used to record how the test subjects reacted when a second person was administered painful electric shocks. Then, the video game phase of the experiment began, during which the test subjects came to the research laboratory seven times to play a video game for one hour each time.

The participants in the experimental group played a highly violent version of the game Grand Theft Auto V and were given the task of killing as many other game characters as possible. In the control group, all violence had been removed from the game and the participants were given the task of taking photos of other game characters.

Finally, after the video game phase was over, the test subjects were examined a second time to determine whether their empathic responses had changed.

The analysis of the data showed that the video game violence had no discernible effect on the empathic abilities of the test subjects. The reactions of the participants in the experimental group who were confronted with extreme depictions of violence did not differ statistically from those of the participants who only had to take photos.

In addition, there were no significant differences in the activity of brain regions that had been identified in other studies as being associated with empathy – such as the anterior insular and anterior midcingulate cortex.

Does that mean that concerns about violence in video games are unfounded? The authors advise against jumping to conclusions.

“Precisely because this is such a sensitive topic, we have to be very careful when interpreting these results,” explains lead author Lukas Lengersdorff, who carried out the study as part of his doctoral studies.

“The conclusion should not be that violent video games are now definitively proven to be harmless. Our study lacks the data to make such statements.”

According to the neuroscientist and statistician, the value of the study lies rather in the fact that it allows a sober look at previous results.

“A few hours of video game violence have no significant influence on the empathy of mentally healthy adult test subjects. We can clearly draw this conclusion.

“Our results thus contradict those of previous studies, in which negative effects were reported after just a few minutes of play”. In these previous studies, participants had played the violent video game immediately before data collection.

“Such experimental designs are not able to distinguish the short-term and long-term effects of video games”, explains Lengersdorff.

According to research group leader and co-author Claus Lamm, the study also sets a new standard for future research in this area: “Strong experimental controls and longitudinal research designs that allow causal conclusions to be drawn are needed to make clear statements about the effects of violent video games. We wanted to take a step in this direction with our study”.

Now it is the task of further research to check whether there are no negative consequences even after significantly longer exposure to video game violence – and whether this is also the case for vulnerable subpopulations.

“The most important question is of course: are children and young people also immune to violence in video games? The young brain is highly plastic, so repeated exposure to depictions of violence could have a much greater effect. But of course these questions are difficult to investigate experimentally without running up against the limits of scientific ethics,” says Lamm. https://neurosciencenews.com/empathy-gaming-psychology-25471/

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