Neuroscientists discover new ‘chemical pathway’ in the brain for stress

A team of neuroscientists at the University of Leicester, UK, in collaboration with researchers from Poland and Japan, has announced a breakthrough in the understanding of the ‘brain chemistry’ that triggers our response to highly stressful and traumatic events.

The discovery of a critical and previously unknown pathway in the brain that is linked to our response to stress is announced today in the journal Nature. The advance offers new hope for targeted treatment, or even prevention, of stress-related psychiatric disorders.

Caption: Newly discovered neurochemical cascade promoting stress-induced anxiety. Neuropsin interacts with cell membrane proteins NMDA and EphB2 to induce expression of the Fkbp5 gene.

Advertisement

Researchers map functional connections between retinal neurons at single-cell resolution

By comparing a clearly defined visual input with the electrical output of the retina, researchers at the Salk Institute for Biological Studies were able to trace for the first time the neuronal circuitry that connects individual photoreceptors with retinal ganglion cells, the neurons that carry visual signals from the eye to the brain.

Their measurements, published in the Oct. 7, 2010, issue of the journal Nature, not only reveal computations in a neural circuit at the elementary resolution of individual neurons but also shed light on the neural code used by the retina to relay color information to the brain.

Groups of neurons in the brain rewire by changing images

Neuroscientists studying the mind’s ability to process images have completed the first empirical study to demonstrate, using animal models, how populations of nerve cells in visual cortex adapt to changing images. Their findings could lead to sight-improving therapies for people following trauma or stroke. The study at The University of Texas Health Science Center at Houston appears in the March 13 issue of the journal Nature.

New MIT tool probes brain circuits

Researchers at the Picower Institute for Learning and Memory at MIT report in the Jan. 24 online edition of Science that they have created a way to see, for the first time, the effect of blocking and unblocking a single neural circuit in a living animal.

This revolutionary method allowed Susumu Tonegawa, Picower Professor of Biology and Neuroscience, and colleagues to see how bypassing a major memory-forming circuit in the brain affected learning and memory in mice.

Monkeys can perform mental addition

Researchers at Duke University have demonstrated that monkeys have the ability to perform mental addition. In fact, monkeys performed about as well as college students given the same test.

The findings shed light on the shared evolutionary origins of arithmetic ability in humans and non-human animals, according to Assistant Professor Elizabeth Brannon, Ph.D. and Jessica Cantlon, Ph.D., of the Duke Center for Cognitive Neuroscience.

Novel mechanism for long-term learning identified

Practice makes perfect — or at least that’s what we’re told as we struggle through endless rounds of multiplication tables, goal kicks and piano scales — and it seems, based on the personal experience of many, to be true. That’s why neuroscientists have been perplexed by data showing that at the level of individual synapses, or connections between neurons, increased, repetitive stimulation might actually reverse early gains in synaptic strength. Now, neuroscientists from Carnegie Mellon University and the Max Planck Institute have discovered the mechanism that resolves this apparent paradox. The findings are published in the Jan. 4 issue of Science.

Cognitive ‘fog’ of normal aging linked to brain system disruption

Comparisons of the brains of young and old people have revealed that normal aging may cause cognitive decline due to deterioration of the connections among large-scale brain systems. The researchers linked the deterioration to a decrease in the integrity of the brain’s “white matter,” the tissue containing nerve cells that carry information. The researchers found that the disruption occurred even in the absence of pathology associated with Alzheimer’s disease (AD).

Scientists uncover how the brain controls what the eyes see

Vase or face” When presented with the well known optical illusion in which we see either a vase or the faces of two people, what we observe depends on the patterns of neural activity going on in our brains.

“In this example, whether you see faces or vases depends entirely on changes that occur in your brain, since the image always stays exactly the same,” said John Serences, a UC Irvine cognitive neuroscientist.

Diet of Walnuts, blueberries found to improve cognition; may help maintain brain function and treat brain disorders

Junk food junkies take notice. What you eat does more than influence your gut. It also may affect your brain. Increasing evidence shows that mom was right: You should eat your vegetables, and your blueberries and walnuts, too.

Scientists are confirming that this age-old adage is worth following. And new studies show that diet may have implications for those who suffer from certain brain ailments.

Diets containing two percent, six percent, or nine percent walnuts, when given to old rats, were found to reverse several parameters of brain aging, as well as age-related motor and cognitive deficits, says James Joseph, PhD, of the U.S. Department of Agriculture Human Nutrition Research Center at Tufts University in Boston.

Enzymes Key To Brainpower Identified

Bolstering disintegrating neural connections may help boost brainpower in Alzheimer’s disease patients, MIT researchers and colleagues will report in the Nov. 8 issue of Neuron.

The researchers zeroed in on the enzymes that manipulate a key scaffolding protein for synapses, the connections through which brain cells communicate. Synapses are weakened and lost in neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease.

Vaccine thwarts the tangles of Alzheimer’s

A new study by NYU Medical Center researchers shows for the first time that the immune system can combat the pathological form of tau protein, a key protein implicated in Alzheimer’s disease. The researchers, led by Einar Sigurdsson Ph.D. at New York University School of Medicine, created a vaccine in mice that suppresses aggregates of tau. The protein accumulates into harmful tangles in the memory center of the brains of Alzheimer’s patients.

The vaccine successfully slowed the deterioration of motor abilities produced by excessive amounts of tau in the central nervous system of mice, according to the study published in the August 22, 2007 issue of the Journal of Neuroscience. Dr. Sigurdsson plans to conduct follow-up studies using mice that slowly develop tangles and cognitive impairments without movement problems.

New research discovers independent brain networks control human walking

In a study published in the August issue of Nature Neuroscience, researchers at the Kennedy Krieger Institute in Baltimore, Maryland found that there are separate adaptable networks controlling each leg and there are also separate networks controlling leg movements, e.g., forward or backward walking.

These findings are contrary to the currently accepted theory that leg movements and adaptations are directed by a single control circuit in the brain. The ability to train the right and left legs independently opens the door to new therapeutic approaches for correcting walking abilities in patients with brain injury (e.g., stroke) and neurological disorders (e.g., cerebral palsy and multiple sclerosis).

Toward an alternative to stem cells for treating chronic brain diseases

With ethical issues concerning use of discarded embryos and technical problems hindering development of stem cell therapies, scientists in Korea are reporting the first successful use of a drug-like molecule to transform human muscle cells into nerve cells. Their report, scheduled for the August 8 issue of the Journal of the American Chemical Society, a weekly journal, states that the advance could lead to new treatments for stroke, Alzheimer’s disease, Parkinson’s disease and other neurological disorders.

 

Researchers identify mechanism behind fear

Researchers from MIT’s Picower Institute for Learning and Memory have uncovered a molecular mechanism that governs the formation of fears stemming from traumatic events. The work could lead to the first drug to treat the millions of adults who suffer each year from persistent, debilitating fears – including hundreds of soldiers returning from conflict in Iraq and Afghanistan.

Evidence found for novel brain cell communication

n article published today in Proceedings of the National Academy of Sciences provides strong evidence for a novel type of communication between nerve cells in the brain. The findings may have relevance for the prevention and treatment of epilepsy, and possibly in the exploration of other aspects of brain functions, from creative thought processes to mental illnesses such as schizophrenia.

‘Virtual’ mouse brains now available online

A multi-institutional consortium including Duke University has created startlingly crisp 3-D microscopic views of tiny mouse brains — unveiled layer by layer — by extending the capabilities of conventional magnetic resonance imaging.

“These images can be more than 100,000 times higher resolution than a clinical MRI scan,” said G. Allan Johnson, Duke’s Charles E. Putman Distinguished Professor of radiology and professor of biomedical engineering and physics. He is first author of a report describing the innovations set for publication in the research journal NeuroImage. View it online 

Brain’s voluntary chain-of-command ruled by not 1 but 2 captains

A probe of the upper echelons of the human brain’s chain-of-command has found strong evidence that there are not one but two complementary commanders in charge of the brain, according to neuroscientists at Washington University School of Medicine in St. Louis.

It’s as if Captains James T. Kirk and Jean-Luc Picard were both on the bridge and in command of the same starship Enterprise.

In reality, these two captains are networks of brain regions that do not consult each other but still work toward a common purpose — control of voluntary, goal-oriented behavior. This includes a vast range of activities from reading a word to searching for a star to singing a song, but likely does not include involuntary behaviors such as control of the pulse rate or digestion. 

Researchers reverse symptoms in mice of leading inherited cause of mental retardation

Researchers at the Picower Institute for Learning and Memory at MIT have, for the first time, reversed symptoms of mental retardation and autism in mice.

The mice were genetically manipulated to model Fragile X Syndrome (FXS), the leading inherited cause of mental retardation and the most common genetic cause of autism. The condition, tied to a mutated X chromosome gene called fragile X mental retardation 1 (FMR1) gene, causes mild learning disabilities to severe autism.

Why we learn from our mistakes

Psychologists from the University of Exeter have identified an ‘early warning signal’ in the brain that helps us avoid repeating previous mistakes. Published in the Journal of Cognitive Neuroscience, their research identifies, for the first time, a mechanism in the brain that reacts in just 0.1 seconds to things that have resulted in us making errors in the past.

Previous research has shown that we learn more about things for which we initially make incorrect predictions than for things for which our initial predictions are correct. The element of surprise in discovering we are wrong is conducive to learning, but this research is the first to show how amazingly rapid our brain’s response can be. This discovery was made possible through the use of electrophysiological recordings, which allow researchers to detect processes in the brain at the instant they occur.

Blood clotting protein may inhibit spinal cord regeneration

Fibrinogen, a blood-clotting protein found in circulating blood, has been found to inhibit the growth of central nervous system neuronal cells, a process that is necessary for the regeneration of the spinal cord after traumatic injury. The findings by researchers at the University of California, San Diego (UCSD) School of Medicine, may explain why the human body is unable to repair itself after most spinal cord injuries.

Rat’s Neurons ( in dish ) learn how to fly a jet

This is a three year old experiment but still remarkable to watch it in action.

It sounds like the stuff of science fiction: a brain nurtured in a Petri dish learns to pilot a fighter plane as scientists develop a new breed of “living” computer. In ground-breaking experiments in a Florida laboratory, however, that is exactly what is happening. The “brain”, grown from 25,000 neural cells extracted from a single rat embryo, has been taught to fly an F-22 jet simulator by scientists at the University of Florida.

Why Losing Money May Be More Painful Than You Think

Losing money may be intrinsically linked with fear and pain in the brain, scientists have discovered. In a Wellcome Trust study published in the Journal of Neuroscience, researchers have shown that during a gambling task, losing money activated an area of the brain involved in responding to fear and pain.

Memory Restored In Mice Through Enriched Environment: New Hope For Alzheimer’s

Mice whose brains had lost a large number of neurons due to neurodegeneration regained long-term memories and the ability to learn after their surroundings were enriched with toys and other sensory stimuli, according to new studies by Howard Hughes Medical Institute researchers. The scientists were able to achieve the same results when they treated the mice with a specific type of drug that encourages neuronal growth.

When smell cells fail they call in stem cell reserves

Hopkins researchers have identified a backup supply of stem cells that can repair the most severe damage to the nerves responsible for our sense of smell. These reservists normally lie around and do nothing, but when neighboring cells die, the scientists say, the stem cells jump into action. A report on the discovery will appear online next week in Nature Neuroscience.

Seeing the Brain in a New Light

Researchers have devised a clever way to activate neurons in a living mouse by shining light on the surface of the animal’s brain. The “light switch” that turns neurons on is actually a light-sensitive protein that is produced by algae. When this protein is genetically engineered into the neurons of living mice, researchers can precisely trigger those neurons with light, causing them to generate electrical impulses.

Brain networks strengthened by closing ion channels

New Haven, Conn. — Yale School of Medicine and University of Crete School of Medicine researchers report in Cell April 20 the first evidence of a molecular mechanism that dynamically alters the strength of higher brain network connections.

This discovery may help the development of drug therapies for the cognitive deficits of normal aging, and for cognitive changes in schizophrenia, bipolar disorder, or attention deficit hyperactivity disorder (ADHD).

Nanoparticle Research Offers Hope of Artificial Retinas, Prostheses

The world’s first direct electrical link between nerve cells and photovoltaic nanoparticle films has been achieved by researchers at the University of Texas Medical Branch at Galveston (UTMB) and the University of Michigan. The development opens the door to applying the unique properties of nanoparticles to a wide variety of light-stimulated nerve-signaling devices — including the possible development of a nanoparticle-based artificial retina.

Biologically Inspired Vision Systems

Neuroscientists at MIT have developed a computer model that mimics the human vision system to accurately detect and recognize objects in a busy street scene, such as cars and motorcycles.

Such biologically inspired vision systems could soon be used in surveillance systems, or in smart sensors that can warn drivers of pedestrians and other obstacles. It may also help in the development of so-called visual search engines.

Read rest of the story on Technology Review site.

Deconstructing brain wiring, one neuron at a time

Researchers have long said they won’t be able to understand the brain until they can put together a “wiring diagram” – a map of how billions of neurons are interconnected. Now, researchers at the Salk Institute for Biological Studies have jumped what many believe to be a major hurdle to preparing that chart: identifying all of the connections to a single neuron.

In the March 1 issue of the journal Neuron, the researchers describe how they modified the deadly rabies virus, turning it into a tool that can cross the synaptic space of a targeted nerve cell just once to identify all the neurons to which it is directly connected.

Revealing secret intentions in the brain

Every day we plan numerous actions, such as to return a book to a friend or to make an appointment. How and where the brain stores these intentions has been revealed by John-Dylan Haynes from the Max Planck Institute for Human Cognitive and Brain Sciences. For the first time they were able to “read” participants’ intentions out of their brain activity. This was made possible by a new combination of functional magnetic resonance imaging and sophisticated computer algorithms

How does your brain respond when you think about gambling or taking risks?

Should you leave your comfortable job for one that pays better but is less secure? Should you have a surgery that is likely to extend your life but poses some risk that you will not survive the operation? Should you invest in a risky startup company whose stock may soar even though you could lose your entire investment? In the Jan. 26 issue of the journal Science, UCLA psychologists present the first neuroscience research comparing how our brains evaluate the possibility of gaining versus losing when making risky decisions.

Conceptualizing a cyborg

Investigators at the University of Pennsylvania School of Medicine describe the basis for developing a biological interface that could link a patient’s nervous system to a thought-driven artificial limb. Their conceptual framework – which brings together years of spinal-cord injury research – is published in the January issue of Neurosurgery.

Antioxidants decrease disease in an insect model of Alzheimer’s disease

Alzheimer’s disease (AD) is one of a number of neurodegenerative disorders in which brain cells damaged by naturally occurring chemicals known as reactive oxygen species (ROS) have been observed. However, whether this oxidative damage causes neurodegeneration or is a consequence of it has not been previously determined. A study appearing online on December 14, in advance of publication in the January print issue of the Journal of Clinical Investigation, indicates that oxidative damage is a factor contributing to neurodegeneration in a Drosophila model of neurodegenerative disorders such as AD.

Neural stem cells lend the brain a surprising capacity for self-repair

The brain contains stem cells with a surprising capacity for repair, researchers report in recent issue of the journal Cell. The novel insight into the brain’s natural ability to heal might ultimately have clinical implications for the treatment of brain damage, according to the researchers.

The researchers found that mice whose brains were severely damaged by loss of the genes “Numb” and “Numblike” in one region just after birth showed substantial mending within weeks. They attributed that repair to neural stem cell “escapees” that had somehow retained or restored the genes’ activity and, with it, their regenerative potential.

Imaging pinpoints brain regions that ‘see the future’

Human memory, the ability to recall vivid mental images of past experiences, has been studied extensively for more than a hundred years. But until recently, there’s been surprisingly little research into cognitive processes underlying another form of mental time travel — the ability to clearly imagine or “see” oneself participating in a future event.

Now, researchers from Washington University in St. Louis have used advanced brain imaging techniques to show that remembering the past and envisioning the future may go hand-in-hand, with each process sparking strikingly similar patterns of activity within precisely the same broad network of brain regions.

Vaccine for brain tumors shows promising results

A vaccine for treating a recurrent cancer of the central nervous system that occurs primarily in the brain, known as glioma, has shown promising results in preliminary data from a clinical trial at UCSF Medical Center.

Findings from the first group of six patients in the study, being conducted at the UCSF Brain Tumor Research Center, showed that vitespen (trademarked as Oncophage), a vaccine made from the patient’s own tumor, was associated with tumor-specific immune response in patients with recurrent, high-grade glioma.

Neuroscientists break code on sight

In the sci-fi movie “The Matrix,” a cable running from a computer into Neo’s brain writes in visual perceptions, and Neo’s brain can manipulate the computer-created world. In reality, scientists cannot interact directly with the brain because they do not understand enough about how it codes and decodes information.

Now, neuroscientists in the McGovern Institute at MIT have been able to decipher a part of the code involved in recognizing visual objects. Practically speaking, computer algorithms used in artificial vision systems might benefit from mimicking these newly uncovered codes.

Two nerve cells in direct contact

Movements in space create in humans and animals so-called optical flow fields which are characteristic for the movement in question. In a forward movement, the objects flow by laterally, objects at the front increase in size and objects further away hardly change at all. At a higher level in the visual centre in the brain, there must be a computation of the visual information, so that animals can differentiate between their own movement and movement of their environment and are able to correct their course if necessary. It is important for the analysis of flow fields that the movement information from both eyes is merged so that the whole flow field can be assessed. In their current study, Karl Farrow, Jürgen Haag and Alexander Borst have for the first time proved the direct link between two nerve cells, one in each half of the brain, combining the movement signals from both the facetted eyes of a fly.

Researchers discover misfolded protein clumps common to dementia, Lou Gehrig’s disease

Scientists have identified a misfolded, or incorrectly formed, protein common to two devastating neurological diseases, frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease), according to a report in the Oct. 6, 2006, issue of Science. The findings suggest that certain forms of FTD, ALS and possibly other neurological diseases might share a common pathological process.

Part Of Human Brain Functions Like A Digital Computer

A region of the human brain that scientists believe is critical to human intellectual abilities surprisingly functions much like a digital computer, according to psychology Professor Randall O’Reilly of the University of Colorado at Boulder.

The finding could help researchers better understand the functioning of human intelligence.

A natural chemical found in strawberries boosts memory in healthy mice

Mothers have long exhorted their children to eat their fruit and vegetables. But once kids are beyond mom’s watchful eye, the hated greens often go the way of Barbie dolls and power rangers. Now, there’s another reason to reach for colorful fruits past adolescence.

Fisetin, a naturally occurring flavonoid commonly found in strawberries and other fruits and vegetables, stimulates signaling pathways that enhance long-term memory, report researchers at the Salk Institute for Biological Studies in this week’s Online Early Edition of the Proceedings of the National Academy of Sciences.

Researchers discover mechanism that determines when detailed memories are retained

The levels of a chemical released by the brain determine how detailed a memory will later be, according to researchers at UC Irvine.

The neurotransmitter acetylcholine, a brain chemical already established as being crucial for learning and memory, appears to be the key to adding details to a memory. In a study with rats, Norman Weinberger, research professor of neurobiology and behavior, and colleagues determined that a higher level of acetylcholine during a learning task correlated with more details of the experience being remembered. The results are the first to tie levels of acetylcholine to memory specificity and could have implications in the study and treatment of memory-related disorders.

Elevated testosterone kills nerve cells

-A Yale School of Medicine study shows for the first time that a high level of testosterone, such as that caused by the use of steroids to increase muscle mass or for replacement therapy, can lead to a catastrophic loss of brain cells.

Taking large doses of androgens, or steroids, is known to cause hyperexcitability, a highly aggressive nature, and suicidal tendencies. These behavioral changes could be evidence of alterations in neuronal function caused by the steroids, said the senior author, Barbara Ehrlich, professor of pharmacology and physiology.

Calorie restriction in non-human primates may prevent and reduce Alzheimer’s disease neuropathology

A new study directed by Mount Sinai School of Medicine extends and strengthens the research that experimental dietary regimens might halt or even reverse symptoms of Alzheimer’s Disease (AD).

Study Provides Insight Into How the Brain Loses Plasticity of Youth

A protein once thought to play a role only in the immune system could hold a clue to one of the great puzzles of neuroscience: how do the highly malleable and plastic brains of youth settle down into a relatively stable adult set of neuronal connections?

Harvard Medical School researchers report in the August 17 Science Express that adult mice lacking the immune system protein paired-immunoglobulin like receptor-B (PirB) had brains that retained the plasticity of much younger brains, suggesting that PirB inhibits such plasticity.

Study provides new insights into brain organization

Scientists have provided new insights into how and why the brain is organised – knowledge which could eventually inform diagnosis of and treatments for conditions like Alzheimer’s disease and autism.

A study by Newcastle University, UK, and the International University Bremen, Germany, debunked a prevailing theory that the nervous system should have mainly very short nerve fibre connections between nerve cells, or neurons, to function at its most effective.

Instead the study, which carried out a sophisticated computer analysis of public databases containing detailed information of worldwide anatomical studies on primate and worm brains, found that long nerve fibre connections were just as vital to overall brain function as short ones.

Researchers watch brain in action

For the first time, scientists have been able to watch neurons within the brain of a living animal change in response to experience.

Thanks to a new imaging system, researchers at MIT’s Picower Institute for Learning and Memory have gotten an unprecedented look into how genes shape the brain in response to the environment. Their work is reported in the July 28 issue of Cell.

Researchers calculate human eye transmits information to the brain at the rate of an ethernet

Researchers at the University of Pennsylvania School of Medicine estimate that the human retina can transmit visual input at about the same rate as an Ethernet connection, one of the most common local area network systems used today. They present their findings in the July issue of Current Biology. This line of scientific questioning points to ways in which neural systems compare to artificial ones, and can ultimately inform the design of artificial visual systems.

Two broad classes of ganglion cell types in the guinea pig retina: brisk cells, which are larger and transmit electrical impulses faster, and sluggish, which are smaller and slower

Researchers Show How Brain Decodes Complex Smells

Duke University Medical Center researchers have discovered how the brain creates a scent symphony from signals sent by the nose.

In studies in mice, the researchers found that nerve cells in the brain’s olfactory bulb — the first stop for information from the nose — do not perceive complex scent mixtures as single objects, such as the fragrance of a blooming rose. Instead, these nerve cells, or neurons, detect the host of chemical compounds that comprise a rose’s perfume. Smarter sections of the brain’s olfactory system then categorize and combine these compounds into a recognizable scent. According to the researchers, it’s as if the brain has to listen to each musician’s melody to hear a symphony.

Humans may rely on the same smell decoding system, because mice and men have similar brain structures for scent, including an olfactory bulb, the researchers said.

Controlling movement through thought alone

A man with paralysis of all four limbs could directly control objects around him – open simulated email, play a game of Pong, adjust the volume on the television set – using only his thoughts. These pilot clinical trial findings, featured on the cover of Nature, mark a major advance in neuroscience, one that offers hope to people with severe motor impairments.