Christen Brownlee The burn of hot peppers and the searing pain of a spider bite may have a common cause. New research suggests that molecules in hot peppers and in a certain spider's venom target the same receptor on nerve cells. Several years ago, scientists identified a channel on neurons that's opened by capsaicin, the molecule responsible for peppers' burn. Follow-up research showed that this channel is a member of a family of cell-surface receptors that sense both chemicals and temperature. When these channels are activated, ions flood into nerve cells and cause them to fire. Although scientists have already studied components of spider venom that cause shock, paralysis, and death, little is known about the molecules that cause the pain. David Julius of the University of California, San Francisco and his colleagues wondered whether pain-inducing venom ingredients might activate the dual-purpose cell-surface channels. The team purchased venoms collected from a variety of spider, scorpion, and snail species known to deliver painful bites. The researchers diluted the venoms and added them to dishes containing human-kidney cells that had been genetically altered to carry various types of channels. ©2006 Science Service.

Keyword: Pain & Touch; Neurotoxins
Link ID: 9608 - Posted: 06.24.2010

BUFFALO, N.Y. -- A 40-year-old woman in good health falls and hits her head while visiting her roommate at her workplace. After a trip to the emergency department, her roommate takes her home with limited instructions. Two days later she finds her dead in her bedroom from a brain hemorrhage. This tragic, but true, vignette illustrates the problem of patients leaving emergency departments after suffering a concussion or mild traumatic brain injury without clear and thorough information about the signs of impending complications. In a study published in a recent issue of Brain Injury, researchers at the University at Buffalo found that discharge sheets from 14 of 15 hospitals that were reviewed lacked at least one important sign of a possible hemorrhage. Ten of the hospitals were located in Western New York; five were located in southern Ontario, Canada. In addition, most instruction sheets were written at too high a reading level. Some suggestions for concussion management were simply wrong, said Michael Fung, M.D., a Canadian physician doing a fellowship in UB's Sports Medicine Institute and the study's lead author. The signs accepted by brain specialists as associated most consistently with hemorrhage or equally dangerous swelling in the brain following a blow to the head are: vomiting, a worsening headache, amnesia or short-term memory loss, worsening mental status, loss of motor function or vision or speech and seizure, the study notes. © 2006 University at Buffalo.

Keyword: Brain Injury/Concussion
Link ID: 9607 - Posted: 06.24.2010

By Rick Weiss Blind mice regained some ability to see after getting transplants of cells taken from the eyes of other mice, strengthening the prospect that it may someday be possible to restore vision in some people who have lost most or all of their eyesight, scientists reported yesterday. Researchers in London and Michigan who did the work warned that it would be years before similar efforts might be tried in people who have lost their vision from macular degeneration or other kinds of blindness that might respond to the treatment. But they said the new study showed for the first time that light-detecting retina cells -- which in this case were taken from other animals but which scientists have begun to grow from human embryonic stem cells -- can orient themselves properly after being injected into a blind eye, connect to other nerve cells and communicate appropriately with visual centers in the brain. "It's still at the research stage, but it's very promising," said Anand Swaroop, a professor of ophthalmology, visual science and human genetics at the University of Michigan Medical School's W.K. Kellogg Eye Center in Ann Arbor. Swaroop led seminal work in recent years that identified the cells in the eye's retina that grow into "rod" cells during fetal development -- the cells that are responsible for black-and-white vision. © 2006 The Washington Post Company

Keyword: Vision; Regeneration
Link ID: 9606 - Posted: 06.24.2010

Poor Bridget Jones. At the beginning of the first film about her diary and life, the character, played by actress Renée Zellweger, is fat and alone in her apartment where she mimes one of the great self-pitying song hits of all time: "All by Myself." But Bridget's problem may be more than skin deep. In new research, reported in the current online issue of the journal Social Neuroscience, researchers from the University of Georgia and San Diego State University report for the first time that social exclusion actually causes changes in a person's brain function and can lead to poor decision-making and a diminished learning ability. "Our findings indicate that social rejection can be a powerful influence on how people act," said W. Keith Campbell, a psychologist who led the research. The new research is the first to examine subjects' brain patterns following social exclusion using the magnetoencephalography (MEG) technique. Researchers have known for a long time that there is a link between social exclusion and the failure of self-control. For instance, people who are rejected in social situations often respond by abusing alcohol, expressing aggression or performing poorly at school or work. (Bridget Jones chooses "vodka and Chaka Khan.") The new study, however, is the first to use MEG to show that there are actual changes inside the brain when test subjects are manipulated to feel socially excluded.

Keyword: Stress
Link ID: 9605 - Posted: 11.11.2006

Researchers at UC Irvine have found that how much detail one remembers of an event depends on whether a certain portion of the brain is activated to “package” the memory. The research may help to explain why sometimes people only recall parts of an experience such as a car accident, and yet vividly recall all of the details of a similar experience. In experiments using functional magnetic resonance imaging (fMRI), the scientists were able to view what happened in the brains of subjects when they experienced an event made up of multiple contextual details. They found that participants who later remembered all aspects of the experience, including the details, used a particular part of the brain that bound the different details together as a package at the time the event occurred. When this brain region wasn’t activated to bind together the details, only some aspects of an event were recalled. The findings appear in the current issue of Neuron. “This study provides a neurological basis for what psychologists have been telling us for years,” said Michael Rugg, director of UCI’s Center for the Neurobiology of Learning and Memory and senior author of the paper. “You can’t get out of memory what you didn’t put into it. It is not possible to remember things later if you didn’t pay attention to them in the first place.” © Copyright 2002-2006 UC Regents

Keyword: Learning & Memory
Link ID: 9604 - Posted: 06.24.2010

By TINA KELLEY NEWARK, — A New Jersey couple filed suit against Aetna Inc., the Hartford-based insurance company, on Wednesday, claiming that it refused to fully cover their daughter’s treatment for anorexia. More Multimedia: Slide Show: At the Polls Slide Show: Spitzer on the Trail The suit was filed in United States District Court here. The couple, Cliff and Maria DeAnna of Mountainside, N.J., said Aetna refused to pay for nearly 10 weeks of their daughter’s inpatient treatment, saying her eating disorder was not “biologically based.” Insurers have balked at covering mental illnesses that they say do not have a proven physiological basis. Ms. DeAnna, who declined to provide her daughter’s given name for privacy reasons, said by phone that she had been hospitalized for 101 days so far this year but that Aetna U.S. Healthcare H.M.O. would pay for only 35 inpatient days. Symptoms of anorexia include excessive dieting and exercise and a distorted belief that one is overweight. The case is an example of what advocates for the mentally ill call longstanding inequities in insurance coverage for psychological ailments. The family’s lawyer, Bruce Nagel, said state law required insurers to provide the same coverage for mental and nervous conditions as for physiological diseases, like heart ailments or emphysema. The suit estimates that hundreds of people in New Jersey have had similar difficulties receiving coverage, and it seeks certification as a class action. Ms. DeAnna estimates that her family has paid almost $100,000 in medical bills this year alone, with the help of a home equity loan. Her daughter, who is 20 and stands 5-foot-6, weighed 102 pounds when she last went into the hospital. Copyright 2006 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 9603 - Posted: 06.24.2010

Washington, DC -- Neuroscientists had long believed that the only way to repair a spinal cord injury was to grow new neural connections, but researchers at Georgetown University Medical Center have found that, especially in young rats, powerful cells near the injury site also work overtime to restrict nerve damage and restore movement and sensation. The same process does not work as efficiently in adult rats and thus recovery time is much longer, the researchers also discovered. But they say that now that they know such a mechanism exists, it may be possible one day to “switch” these cells on therapeutically ? and possibly help humans function better following serious spinal cord injuries. “No one knew cells in the spinal cord acted to protect nerves in this way, so it gives us some hope that in the future we could stimulate this process in the clinic to enhance recovery and ensure the best outcome possible for patients,” said the senior author, Jean R. Wrathall, Ph.D., professor in the Department of Neuroscience. “This is an animal study, however, and there is much work to do to understand more about this process and how it might be altered,” Wrathall said. The study, whose first author is graduate student Philberta Y. Leung, is published in the November 2006 issue of the journal Experimental Neurology.

Keyword: Regeneration
Link ID: 9602 - Posted: 06.24.2010

Our eyes are constantly making saccades, or little jumps. Yet the world appears to us as a smooth whole. Somehow, the brain's visual system "knows" where the eyes are about to move and is able to adjust for that movement. In a paper published online this week in Nature, researchers at the University of Pittsburgh and the National Eye Institute (NEI) for the first time provide a circuit-level explanation as to why. "This is a classic problem in neuroscience," says Marc Sommer, assistant professor of neuroscience at Pitt, who coauthored the paper with Robert Wurtz, senior investigator at NEI, one of the National Institutes of Health. "People have been searching for a circuit to accomplish this stability for the last 50 years, and we think we've made good progress with this study." In 1950, Nobel laureate Roger Sperry hypothesized that when the brain commands the eyes to move, it also sends a corollary discharge, or internal copy, of that command to the visual system. Sommer and Wurtz showed in a 2002 Science paper that a pathway from brainstem to frontal cortex conveys a corollary discharge signal in the brains of monkeys. They suggested that this pathway might cause visual neurons of the cortex to suddenly shift their receptive field--their window on the world--just before a saccade. Such neurons with shifting receptive fields had been discovered by Pitt Professor of Neuroscience Carol Colby and colleagues in 1992.

Keyword: Vision
Link ID: 9601 - Posted: 11.09.2006

Helen Pearson Using a technique that may one day help blind people to see, researchers have shown in mice that retinal cells from newborns transplanted into the eyes of blind adults wire up correctly and help them to detect light. The finding challenges conventional biological thinking, because it shows that cells that have stopped dividing are better for transplantation than the stem cells that normally make new cells. For decades, researchers have sought a way to replace the light-detecting cells that carpet the back of our eyes — and which break down in diseases such as retinitis pigmentosa and macular degeneration. But they have struggled to find cells that will work normally after being transplanted into the eye. To find the best cell type, researchers led by Anand Swaroop at University of Michigan, Ann Arbor, and Robin Ali at University College London, UK, extracted cells from the retinas of mice at various times when photoreceptors are normally being generated, as embryos and after they are born. They then injected these cells into adult mouse retinas and counted how many new photoreceptors were generated. Cells produced in the few days after birth generated the most new photoreceptors after transplantation and connected to the retina correctly, they found. These cells were destined to be photoreceptors but had not fully matured into rods, the cells that detect low light. The results are published in Nature1. ©2006 Nature Publishing Group

Keyword: Vision; Regeneration
Link ID: 9600 - Posted: 06.24.2010

Roxanne Khamsi They may be cold-blooded, but some lizards have warm personalities and like to socialise, a new study shows. A behavioural study reveals that lizards have different social skills: some are naturally inclined to join large groups while others eschew company altogether. The discovery of reptilian personality types could help ecologists better understand and model animal population dynamics, say the researchers involved. Scientists define "personality differences" as consistent behavioural differences between individuals across time and contexts. But there is a need for more research on these differences in wild animals, says Julien Cote of the Pierre and Marie Curie University in Paris, France. "Psychologists have explored the considerable range of non-human personalities like sociability, but mostly on domesticated animals," he says. Cote and colleagues captured wild pregnant common lizards (Lacerta vivipara), and as soon as the offspring were born they were exposed to the scent of other lizards, to test their reactions. Over the next year the team monitored the newly born creatures to see how much time each spent in different areas of their enclosure. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain
Link ID: 9599 - Posted: 06.24.2010

PITTSBURGH -- Timing is everything. For a mouse trying to discriminate between the scent of a tasty treat and the scent of the neighborhood cat, timing could mean life or death. In a striking discovery, Carnegie Mellon University scientists have linked the timing of inhibitory neuron activity to the generation of odor-specific patterns in the brain's olfactory bulb, the area of the brain responsible for distinguishing odors. Their work, appearing in the Nov. 8 issue of the Journal of Neuroscience, describes for the first time a cellular mechanism linking a specific stimulus to the timing at which inhibitory neurons fire. This breakthrough lays a cellular foundation for the "temporal coding hypothesis," which proposes that odor identity is encoded by the timing of neuronal firing and not the rate at which neurons fire. Past research has shown that specific odors trigger unique patterns of electrical activity in the brain. Generating these patterns requires reliably timed inhibition, but relatively little was known about the timing of the activity of inhibitory neurons -- until now. "There is a clear link between which odor is being presented and the time at which inhibitory neurons fire. This timing controls which excitatory neurons are active and at which time. This modulation contributes to the generation of reliable temporal patterns of neuronal activity," said Nathan Urban, an assistant professor of biological sciences at the Mellon College of Science at Carnegie Mellon.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 9598 - Posted: 11.08.2006

by Mary Tucker The sense of smell often seems like the forgotten sense, perhaps because scent cannot be transmitted as obviously as images or sound. But watch a dog - with a sense of smell about a million times more sensitive than ours - identify a person by their smell or sniff out traces of drugs and it is obvious what a powerful means of communication it can be. For humans, scent plays a big role in attraction and is strongly tied to memory. But how is smell written into molecules? And how do our noses interact with scent molecules? Since classical times, scientists have been trying to pin down solid olfactory rules but they still don't know exactly how the nose works. Decoding the shape of smell What we do know is the world is made of atoms and those atoms connect to make molecules. Molecules are what we smell, from wherever they are evaporating, and they reach our nose through the air. Though we know almost everything possible about molecules, we don't know how our nose reads them. Chemists make hundreds of new molecules every week but what each molecule is going to smell like is always a mystery. The prevailing theory, first refined in 1952 by John Amoore at Oxford University, is the shape or steric theory of odor. The theory, simply stated, proposes that the shape of a molecule determines its smell. In other words, a rose molecule smells like a rose molecule because its shape is coded precisely for the nose to interpret this way.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 9597 - Posted: 11.08.2006

By Patricia Reaney LONDON (Reuters) - Exposure to industrial chemicals in the womb or early in life can impair brain development but only a handful are controlled to protect children, researchers said on Wednesday. There is also a lack of research and testing to identify which chemicals cause the most harm or how they should be regulated, they added. "Only a few substances, such as lead and mercury, are controlled with the purpose of protecting children," said Philippe Grandjean of Harvard School of Public Health in Boston, Massachusetts and the University of Southern Denmark. "The 200 other chemicals that are known to be toxic to the human brain are not regulated to prevent adverse effects on the fetus or a small child," he added. In a review published online by The Lancet medical journal, Grandjean and Philip Landrigan of the Mount Sinai School of Medicine in New York identified 202 industrial chemicals known to be toxic to the human brain. They suggested millions of children worldwide may have been harmed by toxic chemicals and may suffer learning disabilities and developmental disorders. But only substances such as lead, methylmercury and polychlorinated byphenyls (PCBs) have been sufficiently studied and regulated. © 1996-2006 Scientific American, Inc.

Keyword: Development of the Brain; Neurotoxins
Link ID: 9596 - Posted: 06.24.2010

Stanford University neuroscientists have designed a gene that enhances memory and learning ability in animals under stress. Writing in the Nov. 8 issue of the Journal of Neuroscience, the Stanford team says that the experimental technique might one day lead to new forms of gene therapy that can reduce the severe neurological side effects of steroids, which are prescribed to millions of patients with arthritis, asthma and other illnesses. "Steroids can mess up the part of the brain involved in judgment and cognition," said neuroendocrinologist Robert Sapolsky, co-author of the study. "In extreme cases it's called steroid dementia. Ideally, if you could deliver this gene safely, it would protect the person from some of these cognitive side effects, while allowing the steroid to do whatever helpful thing it should be doing elsewhere in the body." Sapolsky, the John A. and Cynthia Fry Gunn Professor of Biological Sciences and a professor of neurology and neurological sciences at Stanford, has conducted numerous experiments on the damaging physiological effects of stress and has written extensively on the subject, including a 1995 book, "Why Zebras Don't Get Ulcers." In the Journal of Neuroscience study, Sapolsky and his colleagues focused on the effect of stress on the hippocampus, a part of the brain that's important for learning and memory.

Keyword: Stress; Learning & Memory
Link ID: 9595 - Posted: 11.08.2006

By Jocelyn Kaiser Nobody likes coming down with a fever, but feeling hot may do a body good. Researchers report online 5 November in Nature Immunology that a fever in mice revs up the immune response by helping white blood cells enter lymph nodes, where they join the battle against microbial invaders. All mammals can develop fever when they're sick enough, and even cold-blooded animals with infections, such as fish and lizards, will seek warmth to raise their body temperatures. This suggests that fever somehow helps the body conquer the bugs. Immunologist Sharon Evans of Roswell Park Cancer Institute in Buffalo, New York, and coworkers are studying how fever affects the movement of white blood cells, or lymphocytes, from the blood into lymphoid tissue, where they learn to recognize and fight pathogens. Lymphocytes constantly circulate through blood vessels within lymph nodes and other lymphoid organs, but only some actually enter lymphoid tissue by crossing the walls of the vessels, known as high endothelial venules (HEVs). Fever increases blood flow, which means more lymphocytes flow through lymphoid tissues. Evans' team had previously shown that fever also assists the passage of lymphocytes into lymphoid tissue, but they hadn't figured out what was happening on a molecular level. © 2006 American Association for the Advancement of Science.

Keyword: Neuroimmunology
Link ID: 9594 - Posted: 06.24.2010

For the first time, scientists at the Max Planck Institute for Neurobiology in Martinsried near Munich have been able to show how two nerve cells communicate with each other from different hemispheres in the visual centre. This astoundingly simple circuit diagram could at a later date provide a model for algorithms to be deployed in technical systems (Nature Neuroscience, October 10, 2006) 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. In the blow fly, the nerve cells that analyse optical flow fields, called tangential cells, are located in the lobula plate. There are only 60 of these tangential cells for each half of the brain and each of these 60 cells can be identified individually. The scientists in Martinsried have looked closely at one cell, the H2 cell.

Keyword: Development of the Brain
Link ID: 9593 - Posted: 11.08.2006

PITTSBURGH—Happiness and other positive emotions play an even more important role in health than previously thought, according to a study published in the journal Psychosomatic Medicine by Carnegie Mellon University Psychology Professor Sheldon Cohen. The paper will be available online at www.psychosomaticmedicine.org/. This recent study confirms the results of a landmark 2004 paper in which Cohen and his colleagues found that people who are happy, lively, calm or exhibit other positive emotions are less likely to become ill when they are exposed to a cold virus than those who report few of these emotions. In that study, Cohen found that when they do come down with a cold, happy people report fewer symptoms than would be expected from objective measures of their illness. In contrast, reporting more negative emotions such as depression, anxiety and anger was not associated with catching colds. That study, however, left open the possibility that the greater resistance to infectious illness among happier people may not have been due to happiness, but rather to other characteristics that are often associated with reporting positive emotions such as optimism, extraversion, feelings of purpose in life and self-esteem. Cohen's recent study controls for those variables, with the same result: The people who report positive emotions are less likely to catch colds and also less likely to report symptoms when they do get sick. This held true regardless of their levels of optimism, extraversion, purpose and self-esteem, and of their age, race, gender, education, body mass or prestudy immunity to the virus.

Keyword: Neuroimmunology; Emotions
Link ID: 9592 - Posted: 06.24.2010

By BENEDICT CAREY The passionate, sometimes rhythmic, language-like patter that pours forth from religious people who “speak in tongues” reflects a state of mental possession, many of them say. Now they have some neuroscience to back them up. Researchers at the University of Pennsylvania took brain images of five women while they spoke in tongues and found that their frontal lobes — the thinking, willful part of the brain through which people control what they do — were relatively quiet, as were the language centers. The regions involved in maintaining self-consciousness were active. The women were not in blind trances, and it was unclear which region was driving the behavior. The images, appearing in the current issue of the journal Psychiatry Research: Neuroimaging, pinpoint the most active areas of the brain. The images are the first of their kind taken during this spoken religious practice, which has roots in the Old and New Testaments and in charismatic churches established in the United States around the turn of the 19th century. The women in the study were healthy, active churchgoers. “The amazing thing was how the images supported people’s interpretation of what was happening,” said Dr. Andrew B. Newberg, leader of the study team, which included Donna Morgan, Nancy Wintering and Mark Waldman. “The way they describe it, and what they believe, is that God is talking through them,” he said. Dr. Newberg is also a co-author of “Why We Believe What We Believe.” Copyright 2006 The New York Times Company

Keyword: Language; Brain imaging
Link ID: 9591 - Posted: 06.24.2010

By ERIC NAGOURNEY Emergency room doctors trying to figure out the best way to treat someone who has just had a stroke would be able to follow a more informed course of action if they had an M.R.I. scan of the patient’s brain, a new study finds. For about a decade, doctors have been able to turn to drugs known as clot busters, which can significantly improve the outcome for people whose strokes are caused by a blockage in a blood vessel. The problem is that many strokes involve bleeding in the brain, not clotting, and the clot busters can be fatal in those cases. Although the two types of strokes are different, their symptoms can be the same, and the CT scans commonly given to patients at the hospital can shed only a little light. In the new study, however, researchers led by Dr. Gregory W. Albers of Stanford found that M.R.I. scans could provide information that makes it clearer which patients will benefit from clot busters. The scans may also increase the window of time doctors have to administer them. Under current guidelines, the drugs should not be given more than three hours after a stroke — a problem because many patients do not come in for treatment until after that time has passed. But armed with the M.R.I. results, which show which parts of the brain are damaged beyond repair and which can still be saved, doctors may be able to give the drug later, the study said. Copyright 2006 The New York Times Company

Keyword: Stroke; Brain imaging
Link ID: 9590 - Posted: 06.24.2010

By AMANDA SCHAFFER In ancient Rome, patients with unbearable head pain were sometimes treated with jolts from the electricity-producing black torpedo fish, or electric ray. A.D. 41 In ancient Rome doctors treated the throbbing pain of migraine headaches by applying an electric fish like the black torpedo, top, directly to the head. 2006 It doesn't smell and its shocks are more predictable, but the occipital nerve stimulator, implanted in the head and buttocks, operates on the same principle, bottom. Scribonius Largus, physician to Emperor Claudius, was a staunch advocate of the remedy. “To immediately remove and permanently cure a headache, however long-lasting and intolerable, a live black torpedo is put on the place which is in pain, until the pain ceases and the part grows numb,” he wrote in the first century. Electric fish have long disappeared from the medical armamentarium. And patients with headaches are most frequently treated with pharmaceuticals. But recently, electrical or electromagnetic devices that hark back to the head-zapping torpedo fish have come into vogue among the country’s most prominent migraine researchers. Two different kinds of stimulatory devices are now in large-scale clinical trials for possible use in patients with the most severe migraine cases. Many researchers believe that such devices are likely to play a greater role in migraine treatment in the future. Copyright 2006 The New York Times Company

Keyword: Pain & Touch
Link ID: 9589 - Posted: 06.24.2010