Weekly Neuroscience Update

Credit: eLife (2023)

Researchers have investigated the shared and unique neural processes that underlie different types of long-term memory: general semantic, personal semantic, and episodic memory, suggesting that these memory types all use the same network of the brain, rather than relying on different areas of the brain altogether. This questions a previous theory that characterizes general semantic and episodic memory as two distinct systems. Instead, the authors suggest that different long-term memory types could be viewed as a spectrum, where they rely on activating the same areas of the brain at differing magnitudes.

Scientists can now pinpoint where someone’s eyes are looking just by listening to their ears.

Using a specialized device that translates images into sound, neuroscientists have shown that people who are blind recognize basic faces using the part of the brain known as the fusiform face area, a region that is crucial for the processing of faces in sighted people.

People with long COVID exhibit patterns of changes in the brain that are different from fully recovered COVID-19 patients, according to new research.

What is the mechanism that allows our brains to incorporate new information about the world, and form memories? New work led by Dr. Tomás Ryan from Trinity College Dublin shows that learning occurs through the continuous formation of new connectivity patterns between specific engram cells in different regions of the brain.

New research indicates that acoustic stimulation of the brain may ease persistent symptoms in individuals who have experienced mild traumatic brain injury in the past.

Scientists have discovered that Alzheimer’s-related changes in brain networks extend beyond memory and attention, impacting sensory and motor circuits. These findings challenge previous assumptions about Alzheimer’s effects.

A pivotal discovery in addiction science has found a correlation between microstructural deficits in the prefrontal cortex-habenula tract and the development and maintenance of addiction.

Researchers have unveiled a pioneering technique for charting the intricate conversations occurring within our brains. Such insights are key to decoding behavioral alterations in neurological disease patients. The innovative tool, CaMPARI, allows scientists to witness brain activity in real-time, marking active neurons red and inactive ones green. This breakthrough could offer pathways to better treatments and understanding of diseases like Alzheimer’s.

A team of neuroscientists has found evidence suggesting that the neural development of babies still in the womb is impacted by the language they hear spoken by their mothers as they carry them.

A new study has discovered a link between a new gene pathway and structural brain anomalies in some people who stutter into adulthood, opening up promising research avenues to enhance the understanding of persistent developmental stuttering.

Finally this week, researchers have developed a tool that simplifies the identification of errors in neural networks used for image recognition.

Weekly Neuroscience Update

(A) Brain regions where spectra were measured (yellow box) (B) 1H MR spectrum in the hippocampus: Hippocampal taurine signal shown at 3.4 ppm (arrow). Black line: actual measured spectrum. Red line: LCModel fitting spectrum. Credit: Korea Basic Science Institute (KBSI)

For the first time, a research team in Korea has discovered there is a significant relationship between depression and the taurine concentration in the hippocampus, an area of the brain responsible for memory and learning functions. This discovery provides the opportunity to publicize the role and importance of taurine in future prevention, diagnosis, and treatment of depression.

A recent study reveals that individuals who experienced childhood adversity, such as neglect or abuse, faced higher chances of COVID-19 hospitalization or mortality in adulthood.

Time spent watching television or playing computer games has measurable and long-term effects on children’s brain function, according to a review of 23 years of neuroimaging research, which—while showing negative impacts—also demonstrates some positive effects.

A first-of-its-kind study has identified overactive inflammation and loss of critical protection mechanisms in the brain as potential contributors to suicide risk.

An international team of scientists has uncovered the vital role of microglia, the immune cells in the brain that acts as its dedicated defense team, in early human brain development. By incorporating microglia into lab-grown brain organoids, scientists were able mimic the complex environment within the developing human brain to understand how microglia influence brain cell growth and development.

A novel study finds a link between childhood physical fitness and cerebellar grey matter volume in adolescents.

Mayo Clinic researchers have identified new scoring criteria allowing for the detection of treatable forms of rapidly progressive dementia (RPD) with reasonably high confidence during a patient’s first clinical visit. This scoring criteria may allow physicians to substantially reduce the time it takes to begin treatment. The findings are published in the Annals of Neurology.

A new sudy has identified the top three genes responsible for traumatic brain injury complications.

Researchers have made a discovery that sheds light on how our brain cells manage to efficiently replace older proteins. This process is crucial for maintaining effective neural communication and ensuring optimal cognitive function.

A pair of studies has uncovered novel cellular mechanisms that are involved in two types of genetic amyotrophic lateral sclerosis, or ALS.

In a study published in the Journal of Neuroscience Research, psychological assessments indicated that people who regularly use cannabis, or marijuana, tend to have a greater understanding of the emotions of others. Brain imaging tests also revealed that cannabis users’ anterior cingulate—a region generally affected by cannabis use and related to empathy—had stronger connectivity with brain regions related to sensing the emotional states of others within one’s own body.

Finally this week, researchers have unearthed the genetic connection between the heart and brain related to fainting spells.

What Happens To Your Brain As You Age?

As the most complex organ in your body, your brain changes radically throughout your life. Starting from before birth and continuing even after you’ve died.

As we age, the brain undergoes several transformations that can impact its structure and function. These changes are part of the natural aging process, and while they are normal, they can sometimes affect certain aspects of cognitive function.

Let’s explore some general trends associated with aging and the brain:

Shrinking of Brain Volume: As people age, there is a gradual reduction in overall brain volume. This is primarily due to a decrease in the size and weight of individual neurons, as well as a reduction in the number of synapses (connections between neurons). The frontal cortex, important for functions such as decision-making and problem-solving, is particularly vulnerable to age-related volume loss.

Reduced Blood Flow: Another notable change in the aging brain is the decrease in blood flow. This reduced circulation can affect the delivery of essential nutrients and oxygen to brain cells, potentially impacting cognitive functions such as memory and attention.

Changes in Neural Communication: Aging can disrupt the intricate network of neural connections within the brain. These disruptions may lead to slower information processing, difficulty in multitasking, and challenges in forming new memories. However, the brain has a remarkable ability to adapt and compensate for these changes, often finding alternative pathways to complete tasks.

Altered Neurochemical Balance: The aging process can also impact the production and regulation of various neurotransmitters. These chemical messengers play a vital role in synaptic communication. Imbalances in neurotransmitters like dopamine and serotonin can affect mood, motivation, and overall cognitive function.

Increased Risk of Neurodegenerative Diseases: While not an inevitable consequence of aging, the risk of developing certain neurodegenerative disorders such as Alzheimer’s disease or Parkinson’s disease does increase with age. These conditions can have a profound impact on memory, movement, and other cognitive abilities.

It’s important to note that while these trends are commonly seen in the aging brain, everyone’s experience is unique. Many factors, including genetics, lifestyle choices, and overall health, can influence how an individual’s brain ages. Adopting a healthy lifestyle, including regular physical exercise, a balanced diet, cognitive stimulation, and social engagement, can contribute to maintaining brain health as one ages. Additionally, ongoing research aims to better understand the aging brain and develop strategies to promote cognitive well-being in older individuals.

    Examining the Neural Impact of Zoom: Research Reveals Diminished Neural Signaling

    Using sophisticated imaging tools, Yale neuroscientist Joy Hirsch tracked in real-time the brain activity of two people engaging in conversation and discovered an intricate choreography of neural activity in social interaction areas.

    A similar experiment performed with two people using Zoom, the ubiquitous video conferencing platform, revealed a very different neural landscape. In online exchanges, neural activity was substantially suppressed compared with activity observed in face-to-face conversations.

    Compared to “in-person” conversations, Zoom reduced neural signaling significantly. In face-to-face conversations, increased activity was associated with longer gaze times and larger pupil diameters, indicating more arousal in the two brains. Additionally, more coordinated neural activity was found between brains of people conversing in person, suggesting that social cues between people conversing in person were being exchanged more reciprocally.

    These findings illustrate how important live, face-to-face interactions are to our natural social behaviors, Hirsch said. “Online representations of faces, at least with current technology, do not have the same ‘privileged access’ to social neural circuitry in the brain that is typical of the real thing,” she said.

    The findings were published Oct. 25 in the journal Imaging Neuroscience. Nan Zhao et al, Separable Processes for Live “In-Person” and Live “Zoom-like” Faces, Imaging Neuroscience (2023).

    Weekly Neuroscience Update

    Credit: Nature Mental Health (2023)

    Researchers have identified important new methods for accurately identifying possible biomarkers in adolescent brains that can reliably predict cognitive developments and psychiatric issues.

    A new study has examined the neural processes underlying odor processing in the human olfactory system and how the brain handles odor information from different nostrils and details the finding that each nostril has its own sense of smell, recording a distinct representation of the odor information it encounters.

    A groundbreaking discovery suggests that dendrites could be pivotal in learning processes and may even influence our understanding of brain states and degenerative diseases.

    A new study reveals the brain’s swift response to human errors compared to unintended outcomes. The study found that the brain recognizes an error within one second and then engages in a longer process to prevent future errors. This process was absent when the outcome wasn’t a direct result of an action, indicating a specialized error-awareness mechanism in the brain.

    Researchers have identified new therapeutic targets for progressive supranuclear palsy (PSP), an incurable brain disorder with symptoms mimicking Parkinson’s and dementia.

    A speech prosthetic developed by a collaborative team of neuroscientists, neurosurgeons, and engineers can translate a person’s brain signals into what they’re trying to say. The new technology might one day help people unable to talk due to neurological disorders regain the ability to communicate through a brain-computer interface.

    It’s been debated for decades, but now researchers have suggested that left-handedness is not linked to better spatial skills.

    A new study sheds light on when adolescents start thinking like adults. Researchers found that executive function, critical for task-switching and focus, typically matures around 18 years old. Drawing from over 10,000 participants and multiple datasets, this large-scale study offers a developmental chart for teen cognitive growth. These findings are invaluable for education, psychiatry, and the judicial system.

    Emerging research underscores the profound connection between mental health and heart disease, with depression and anxiety hastening the onset of cardiovascular risk factors.

    Researchers have discovered a potential link between the microbe C. perfringens and the progression of multiple sclerosis (MS). The study hints at the prospect of developing a vaccine or alternative treatments in the near future.

    In a new study, researchers use a very large dataset to identify predictive brain imaging-based biomarkers of mental illness in adolescents.

    Using advanced brain scanning technology, a research team has revealed insights into what happens in the brain during an advanced form of meditation called jhana. By uncovering distinct patterns of activity in different regions of the brain during jhana, the research suggests exciting possibilities for innovative therapies merging ancient meditation practices with modern neuroscience to improve well-being.

    Finally this week, new research suggests your biological age, more than the years you’ve lived, may predict your risk of dementia and stroke in the future.

    Decoding Human Existence: How Neurons Map Time and Space Dimensions

    Two studies conducted by UCLA investigators provide fresh perspectives on how neurons in the human brain encode the fundamental elements of consciousness—time and space. These are the cornerstone dimensions of our experience, enabling us to recollect the past and imagine the future.

    By employing specialized depth electrodes, the researchers examined epilepsy patients, uncovering “place cells” related to spatial awareness and “time cells” involved in understanding temporal aspects.

    One of the studies demonstrated the independent yet simultaneous functioning of these cells during navigation tasks. Another study revealed that specific neurons maintained consistent temporal patterns regardless of the speed of external stimuli.

    Two crucial sets of findings emerged:

    1. The human brain encompasses specialized cells such as “place cells” and “grid cells” for spatial mapping and “time cells” for tracking temporal sequences. Notably, during navigation in a virtual environment, place cells exhibit a consistent pattern, while time cells demonstrate variability based on the task at hand. This suggests a notable separation between the neuronal dimensions of time and space.
    2. The discovery of temporally periodic cells (TPCs) reveals distinct periodic behavior across various time scales. This unique behavior potentially serves as a metric for understanding both temporal and spatial representations within the brain.

    Weekly Neuroscience Update

    A new study unveils the existence of traveling waves of the neurochemical acetylcholine in the striatum, a region of the brain responsible for motivating actions and habitual behaviors.

    Researchers have conducted a study aimed at better understanding the patterns in neural network communication associated with ‘bad’ decisions made while gambling. Their paper, published in Frontiers in Neuroscience, shows that different types of ‘bad’ decisions made while gambling, namely avoidant and approach decisions, are associated with distinct neural communication patterns.

    What determines how a teenager’s brain is structured and how it evolves? Researchers have established a close link between brain activity and a maturation process called cortical thinning.

    Researchers have found COVID-19 does not appear to cause direct brain damage or viral invasion. In blood or cerebrospinal fluid samples, no abnormal biomarkers were found. The findings thus suggest that post-COVID condition is not the result of ongoing infection, immune activation, or brain damage.

    A recent study finds differences in functional brain connectivity in people with and without psychosis and schizophrenia that could help researchers understand the neural underpinnings of this disease.

    Brain health in people over age 50 deteriorated more rapidly during the pandemic, even if they didn’t have COVID-19, according to major new research linking the pandemic to sustained cognitive decline. The cognitive decline seems to have been exacerbated by several factors during the pandemic, including an increase in loneliness and depression, a decrease in exercise, and higher alcohol consumption.

    Prenatal lead exposure is associated with an increased risk for cognitive developmental delay in children, according to a new study.

    Children who are too short for their age can suffer reduced cognitive ability arising from differences in brain function as early as six months of age, according to new research. Stunted growth had previously been linked with poor cognitive outcomes later in life, but this is the first time that this association has been found in infancy. It is also the first time stunted growth has been linked to functional differences in how the brain works in early development.

    Finally this week, researchers have developed a new method for mapping how the parts of the brain “speak” to each other, critical to understanding behavior changes in patients with neurological disease.

    Weekly Neuroscience Update

    An international team of researchers has published a digital atlas showing how the normative maturation of the fetal brain occurs between 14 – 31 weeks’ gestation, a critical developmental period.

    New findings suggest that measuring changes in how pupils react to light could help predict recovery from depression and personalize transcranial magnetic stimulation (TMS) treatment of major depressive disorder.

    A new study has found the influence of language on human thinking could be stronger than previously assumed. 

    Scientists at Imperial College London are leading the development and testing of a new method of stimulating the brain, which could provide an alternative treatment for brain diseases such as Alzheimer’s, and its associated memory loss.

    Researchers report neural signaling during online exchanges is considerably reduced compared to face-to-face conversation.

    Two different regions of the brain are critical to integrating semantic information while reading, which could shed more light on why people with aphasia have difficulty with semantics, according to new research.

    Finally this week, researchers in Canada have examined what type of music helps to dampen pain perception.

    Weekly Neuroscience Update

    Study summary graphic. Credit: Mount Sinai Health System

    A team of researchers has created the first “multiome” atlas of brain cell development in the human cerebral cortex across six broad developmental time points from fetal development into adulthood, shedding new light on their roles during brain development and disease.

    A new study links rhythmic oscillations in ovarian hormone levels in women during the menstrual cycle to changes in brain structure.

    Researchers at Monash University have identified a new way of mapping ‘phosphenes’—the visual perception of the bright flashes we see when no light is entering the eye—to improve the outcome of surgery for patients receiving a cortical visual prosthesis (‘bionic eye’).

    newly published atlas offers the most detailed maps yet of the location, structure, and, in some cases, function of more than 3,000 types of brain cells.

    Researchers have analyzed more than a million human brain cells to produce detailed maps of gene switches in brain cell types and revealed the links between specific types of cells and various common neuropsychiatric disorders.

    A new study shows that teenagers with OCD experience deficits in decision-making and behavioral control. This is linked to abnormal activity in an area of the brain called the orbitofrontal cortex (OFC).

    Severe inflammation in early childhood is a clinically known risk factor for developing autism and schizophrenia. Now, for the first time, scientists have discovered that inflammation alters the development of vulnerable brain cells, and this could have mechanistic links to neurodevelopmental disorders. This finding could lead to treatments for many different childhood-onset neurodevelopmental disorders.

    Scientists have discovered widespread differences in metal levels in the brains of patients with Huntington’s disease, a type of dementia, compared to a control group with healthy tissue.

    In two parallel projects, researchers have been involved in creating the most comprehensive atlases of human brain cells to date. The two studies provide clues on different brain diseases and give hope for medical advancements in the future, such as new cancer drugs.

    In a suite of new studies, a large consortium of researchers shares new knowledge about the cells that make up our brains and the brains of other primates.

    The brains of people who reduce their drinking, as well as of people who quit drinking entirely, have greater volume in certain regions than people who drink more heavily, according to a new study of adults treated for alcohol use disorder. 

    Sleeping patterns and stress hormones could be the key to understanding how and when people with epilepsy are likely to experience seizures, a new study reveals.

    New research has found molecular evidence highlighting important sex differences in the brains of people with major depressive disorder, with evidence of changes occurring specifically in the female brain, but not in males.

    Finally this week, new research has found that MRI scans can reveal the parts of the brain that are involved in responding to fatty foods.

    Weekly Neuroscience Update

    Schematic of preprocessing and model training

    Researchers have, for the first time ever, used AI to develop an algorithm they term “HistoAge” which predicts age at death based on the cellular composition of human brain tissue specimens with an average accuracy of within 5.45 years. This powerful tool can also identify neuroanatomical regions vulnerable to age-related changes, an indicator of potential cognitive diseases.

    Scientists have uncovered why night shift work is associated with changes in appetite. The findings could help the millions of people who work through the night and struggle with weight gain.

    The brain circuitry disrupted in Alzheimer’s disease appears to influence memory through a type of brain wave known as theta oscillation, a team of researchers report. The findings, published in Nature Communications, could help researchers design and evaluate new treatments for Alzheimer’s, a condition that affects millions of people around the globe and has no cure.

    A new study suggests that a healthy heart may help prevent Alzheimer’s—and this gives hope for new treatments.

    Researchers have shown the potential of a new gene therapy approach to silence human sensory neurons (nerve cells) as a means of treating persistent pain. Many current drugs for chronic pain are highly addictive, which makes it important to discover new alternatives.

    Scientists have developed new tools, based on AI language models, that can characterize subtle signatures in the speech of patients diagnosed with schizophrenia.

    Can plant-derived nutrients alter gut bacteria to affect brain function? A team of scientists investigated this question in a study of overweight adults. Their findings, published in the journal Gut, suggest that dietary fiber can exert influence on both the composition of gut bacteria and the reward signals in the brain and associated food decision-making.

    New guidance has been issued for clinicians on the determination of brain death, also known as death by neurologic criteria

    Researchers have shown it is possible to detect tell-tale signs of Parkinson’s disease 20–30 years before symptoms appear. Their work opens the door to screening programs and preventative treatments long before irreversible damage is done.

    Finally this week, there is evidence that some form of conscious experience is present by birth, and perhaps even in late pregnancy, an international team of researchers has found.