Tom Simonite The most common form of colour blindness makes it difficult for those with the condition to distinguish between red and green. But scientists have found that it also helps these people to discern subtle shades of khaki that look identical to those with normal vision. About six percent of men, and a much smaller fraction of women, have deuteranomaly, commonly known as red-green colour blindness. It is caused by a genetic mutation that affects one of the three pigments found in the cone-shaped cells in the retina that respond to different colours of light. This mutation alters the pigment that responds to green light so that it behaves more like the red-sensitive pigment. Therefore, the two colours produce almost identical responses in the eye. This means that people with deuteranomaly often cannot see differences between shades of red and green on test cards used by scientists to investigate the disorder. Now researchers based at the University of Cambridge, UK, and the University of Newcastle upon Tyne, UK, have turned the tables. They designed test cards that deliberately favoured people with deuteranomaly to show that these individuals can spot differences between shades of khaki that look identical to those with normal vision. Their work is published in the journal Current Biology1. © 2004 Nature Publishing Group

Keyword: Vision; Evolution
Link ID: 8264 - Posted: 06.24.2010

By DAVID WILLIAMSON UNC News Services CHAPEL HILL – By age 2, children with the often-devastating neurological condition physicians call autism show a generalized enlargement of their brains, a new University of North Carolina at Chapel Hill and Duke University medical schools study concludes. Exactly why this roughly 5 percent greater brain growth occurs and what it means are not yet clear, scientists said. Indirect evidence suggested that the increased brain growth probably began during the later months of the children’s first year of life. A report on the finding appears in the December issue of the Archives of General Psychiatry. UNC authors are Dr. Heather Cody Hazlett, assistant professor of psychiatry; Dr. Michele Poe, a statistician with the FPG Child Development Institute; Dr. Guido Gerig, professor of computer science; imaging technician Rachel Gimpel Smith; and Drs. John Gilmore and Joseph Piven, professors of psychiatry. At UNC, Piven, the senior author, directs both its Study to Advance Autism Research and Treatment (STAART) Center and its Neurodevelopmental Disorders Research Center. Duke authors are Drs. James Provenzale and Allison Ross, professor of radiology and associate professor of anesthesiology, respectively.

Keyword: Autism
Link ID: 8263 - Posted: 06.24.2010

The stress a married couple experiences during a 30-minute argument can delay their bodies’ ability to heal a wound by at least a day, according to a new study. And if the couples’ relationship endures routine hostility, the delay can be even longer. There could be important implications for people suffering from chronic wounds, such as skin ulcers. “We knew that chronic stress causes reduced immunity, but to find that an argument of just half an hour has such a profound effect on wound healing is quite shocking,” says Patricia Price at the Wound Healing Research Unit at Cardiff University, Wales, who was not involved in the study. Researchers at Ohio State University College of Medicine in the US inflicted small wounds on 42 otherwise healthy married couples, whose ages ranged from 22 to 77. Each partner was wounded on the forearm with a punch biopsy device, which scrapes off eight patches of the skin's surface, each 8 millimetres in diameter, to leave small open sores. Before a blister could form, another device was used to create a protective bubble over each wound from which the researchers could extract the fluids that normally fill such blisters. © Copyright Reed Business Information Ltd.

Keyword: Neuroimmunology; Stress
Link ID: 8262 - Posted: 06.24.2010

A dietary supplement taken during pregnancy could cut the risk of hydrocephalus, research suggests. The condition, known as water on the brain, is often deadly, and survivors can have impaired brain development. It was thought this was due to damage caused by fluid accumulation, but work by Manchester and Lancaster Universities challenges this theory. They believe the key to understanding the condition could be changes to the chemical composition of this fluid. The UK researchers hope their work will eventually lead not only to a reduced risk of hydrocephalus, but also new treatments for those who survive with the condition. Parents of children suffering from the condition in the US have raised money to pay for the next stage of the investigation. The money will fund a lab at the University of Central Florida, which will be staffed by the UK teams. There is currently no unequivocal prenatal diagnosis test or satisfactory treatment for hydrocephalus other than surgical diversion of the fluid through a tube, known as a shunt, from the brain to the abdomen or heart. However, shunts are permanent and prone to infection and blockage, which means patients may require several operations during their lifetime. Lead researcher Dr Jaleel Miyan said: "This procedure is based on the established clinical view that this fluid is nothing more than a mechanical support system within the skull with little, if any, physiological properties and that hydrocephalus is simply a build-up of excess cerebrospinal fluid in the brain. (C)BBC

Keyword: Development of the Brain
Link ID: 8261 - Posted: 12.05.2005

Abnormal activity in neurons that help individuals imitate others may underlie some of the social deficits found in autism, US researchers believe. A Nature Neuroscience study found autistic children had less brain activation in an area involved in understanding others' state of mind. The degree of activation of the 'mirror neurons' housed in this area correlated with measures of social impairment. The lower the activation, the stronger the impairment the children had. Autism affects a person's ability to communicate with others and to respond appropriately to environmental cues. In animals, mirror neurons have been shown to fire both when the animal observes another performing an act and when they perform the same act themselves. Dr Mirella Dapretto and colleagues studied the brain activity patterns of 10 children with autism as the children either imitated facial gestures or passively watched facial gestures. The facial gestures reflected emotions including fear, anger, sadness and happiness. The researchers compared these outcomes with those of 10 children of the same age and IQ but who did not have autism. Although the autistic children were able to perform the task, they had lower activation in a brain area containing mirror neurons - the inferior frontal gyrus pars opercularis - both when watching and imitating facial gestures, compared to the other children. (C)BBC

Keyword: Autism
Link ID: 8260 - Posted: 12.05.2005

By PAUL RAEBURN In the mid-1980's, David Shaffer, a psychiatrist, became disturbed by an increase in teenage suicides. After declining for decades, the rate started climbing in the late 1950's, especially for boys. By the 1980's, it had tripled - to 11.3 per 100,000 teenagers 15 to 19, according to the Centers for Disease Control and Prevention. In more recent surveys of teenagers, the C.D.C. has found that about 8 percent of high-school students answer yes when asked if they had attempted suicide during the past year. About 1,500 succeed annually, making suicide the third-leading cause of death in teenagers after accidents and homicides. Shaffer wanted to know what was happening - and whether anything could be done about it. There were plenty of theories. Defenders of family values blamed working mothers and divorce. Some churches blamed the game Dungeons & Dragons, for its supposed demonic content. One therapist argued that most suicides were committed by gay teenage victims of discrimination. And then there was the music that kids were listening to. "A whole lot of people were criticizing rock stars," Shaffer says. When Shaffer began his research, most people thought suicide was a random act - that little could be done to predict or prevent it. But Shaffer, now chief of the Division of Child and Adolescent Psychiatry at Columbia University, didn't believe that. He studied records of 140 teenagers who committed suicide during the 1980's in and around New York City. Most exhibited at least one of three characteristics. The first was depression. The second was alcohol abuse - found in two-thirds of the 18-year-olds. And the third was aggression - beating somebody up or punching walls. Copyright 2005 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 8259 - Posted: 12.05.2005

New imaging research at UCLA detailed Dec. 4 as an advance online publication of the journal Nature Neuroscience shows children with autism have virtually no activity in a key part of the brain's mirror neuron system while imitating and observing emotions. Mirror neurons fire when a person performs a goal-directed action and while he or she observes the same action performed by others. Neuroscientists believe this observation-execution matching system provides a neural mechanism by which others' actions, intentions and emotions can be understood automatically. Symptoms of autism include difficulties with social interaction -- including verbal and nonverbal communication -- imitation and empathy. The new findings dramatically bolster a growing body of evidence pointing to a breakdown of the brain's mirror neuron system as the mechanism behind these autism symptoms. "Our findings suggest that a dysfunctional mirror neuron system may underlie the social deficits observed in autism," said Mirella Dapretto, lead author and assistant professor in residence of psychiatry and biobehavioral sciences at the Semel Institute for Neuroscience and Human Behavior at UCLA and the David Geffen School of Medicine at UCLA. "Together with other recent data, our results provide strong support for a mirror neuron theory of autism. This is exciting because we finally have an account that can explain all core symptoms of this disorder."

Keyword: Autism
Link ID: 8258 - Posted: 12.05.2005

Completing a daily crossword and enjoying a range of activities and interests has long been accepted as a recipe for maintaining a healthy brain in older age, but the reasons for this have never been clear. Now, scientists at the University of Edinburgh are seeking to identify brain's 'survival' genes which lie dormant in unused brain cells, but are re-awakened in active brain cells. These awakened genes make the brain cells live longer and resist traumas such as disease, stroke and the effects of drugs, and are also critical to brain development in unborn babies. Their findings could lead to the development of smarter drugs or gene therapies to halt the progress of neurological diseases like Alzheimer's and Parkinson's disease and may also explain, scientifically, the benefits to the brain of maintaining an intellectually and physically stimulating lifestyle in later years. Dr Giles Hardingham of the Centre for Neuroscience Research at the University of Edinburgh said: "When brain cells are highly stimulated, many unused genes are suddenly reactivated. We have found that a group of these genes can make the active brain cells far healthier than lazy, inactive cells, and more likely to live a long life. These findings also have implications at the other end of life, where maternal drug taking and drinking can cause these survival genes to be turned off in the brain of unborn babies."

Keyword: Alzheimers; Learning & Memory
Link ID: 8257 - Posted: 12.05.2005

The secret to everlasting love may lie in a specific region of the brain activated by the brain chemical dopamine, say researchers studying prairie voles. The rodents usually form lifelong monogamous pair-bonds with their mating partners, but the researchers found that by manipulating certain dopamine receptors in specific regions of their brains, they could disrupt these relationships and even cause them to become unfaithful. Brandon Aragona at Florida State University in Tallahassee, US, and colleagues examined the “love affair” that develops between prairies voles. After mating once, the male prairie vole not only prefers the company of his mate, but will act aggressively towards other available females. His female partner displays a similar commitment, showing hostility towards other interested male voles. The researchers found that, after a single mating encounter, large amounts of the neurotransmitter dopamine are released into the nucleus accumbens, a sub-cortical region of the brain that is also involved in motivated behaviour and the development of addiction. “Dopamine release is associated with a reorganisation of brain circuitry that changes this region of the brain, promoting pair-bonding,” Aragona explains. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 8256 - Posted: 06.24.2010

WASHINGTON -- A patch developed to treat attention deficit hyperactivity disorder in children received a negative review from a Food and Drug Administration scientist, who concluded the drug cannot be safely marketed. The patch uses methylphenidate, the same drug that is in Ritalin. But FDA reviewer Dr. Robert Levin found the patch produces troubling side effects too often to be considered safe. His findings were in briefing documents released by the agency on Thursday in advance of a public meeting on the drug. The reviewer's findings are not the final word. An independent panel of experts convened by the FDA is expected to consider on Friday whether the patch is effective and safe. The FDA has the final call on whether the patch can be made available, but the agency often follows the advice of its panels. The patch, developed by Noven Pharmaceuticals of Miami and Shire Pharmaceuticals Group in the United Kingdom, goes on a child's hip for nine hours, according to submissions by the company. It releases into the body methylphenidate, a stimulant that calms children with ADHD. It is for children between the ages of 6 and 12. © 2005 The Associated Press

Keyword: ADHD
Link ID: 8255 - Posted: 06.24.2010

By Katherine Unger Think all bees look alike? Well we don't all look alike to them, according to a new study that shows honeybees, who have 0.01% of the neurons that humans do, can recognize and remember individual human faces. For humans, identifying faces is critical to functioning in everyday life. When we look at another person's face, a special brain region, the fusiform gyrus, lights up (ScienceNOW 14 February, 2004). But can animals without such a specialized region also tell one face from another? Knowing honeybees' unusual propensity for distinguishing between different flowers, visual scientist Adrian Dyer of Cambridge University in Cambridge, England, wondered whether that talent stretched to other contexts. So he and his colleagues pinned photographs of four different people's faces onto a board. By rewarding the bees with a sucrose solution, the team repeatedly coaxed the insects to buzz up to a target face, sometimes varying its location. Even when the reward was taken away, the bees continued to approach the target face accurately up to 90% of the time, the team reports in the 2 December Journal of Experimental Biology. And in the bees' brains, the memories stuck: The insects could pick out the target face even two days after being trained. © 2005 American Association for the Advancement of Science.

Keyword: Learning & Memory; Vision
Link ID: 8254 - Posted: 06.24.2010

Christen Brownlee As you sample all the treats that the holiday season has to offer, be thankful for adenosine 5'-triphosphate (ATP). New research suggests that this molecule, typically associated with processing energy in cells, plays a pivotal role in conveying information about foods' tastes to the brain. When food hits the tongue's taste buds, cells there send chemical messages that stimulate nearby nerve fibers. These fibers, in turn, notify the brain of the distinguishing tastes: whether each food is sweet, salty, sour, bitter, or umami—the flavor of monosodium glutamate. Researchers have been missing a key piece of the taste puzzle: the identity of the messenger, known as a neurotransmitter, that sends information from taste buds to the nerve fibers. Scientists have proposed several molecules, including norepinephrine and serotonin, but experiments have ruled out most of the candidates. Sue Kinnamon of Colorado State University in Fort Collins and her team noted that ATP assumes the role of neurotransmitter in a few other places in the body. For example, ATP transmits information about blood-oxygen concentrations from sensors called carotid bodies to nerves. Because both carotid bodies and taste buds detect chemicals, the team wondered whether ATP might be the mystery neurotransmitter, says Kinnamon's colleague Leslie Stone-Roy, also of Colorado State. ©2005 Science Service.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8253 - Posted: 06.24.2010

A team of scientists at UCSF has made a critical discovery that may help in the development of techniques to promote functional recovery after a spinal cord injury. By stimulating nerve cells in laboratory rats at the time of the injury and then again one week later, the scientists were able to increase the growth capacity of nerve cells and to sustain that capacity. Both factors are critical for nerve regeneration. The study, reported in the November 15 issue of the Proceedings of the National Academy of Sciences, builds on earlier findings in which the researchers were able to induce cell growth by manipulating the nervous system before a spinal cord injury, but not after. Key to the research is an important difference in the properties of the nerve fibers of the central nervous system (CNS), which consists of the brain and spinal cord, and those of the peripheral nervous system (PNS), which is the network of nerve fibers that extends throughout the body. Nerve cells normally grow when they are young and stop when they are mature. When an injury occurs in CNS cells, the cells are unable to regenerate on their own. In PNS cells, however, an injury can stimulate the cells to regrow. PNS nerve regeneration makes it possible for severed limbs to be surgically reattached to the body and continue to grow and regain function.

Keyword: Regeneration
Link ID: 8252 - Posted: 12.03.2005

AFP — To the untrained ear monkeys of a certain species may all sound the same, but Japanese researchers have found that, like human beings, they actually have an accent depending on where they live. The finding, the first of its kind, will be published Monday in the December edition of a German scientific journal Ethology, the primate researchers said Tuesday. "Differences between chattering by monkeys are like dialects of human beings," said Nobuo Masataka, professor of ethology at Kyoto University's Primate Research Institute. The research team analyzed voice tones of two groups of the same species of primates, the Japanese Yakushima macaque also known as Macaca fuscata yakui, between 1990 and 2000. One group was formed by 23 monkeys living on the southern Japanese island of Yakushima, and the other group comprised 30 descendants from the same tribe moved from the island to Mount Ohira, central Japan, in 1956. The result showed that the island group had a tone about 110 hertz higher on average than the one taken to central Japan. © 2005 Discovery Communications Inc.

Keyword: Language; Evolution
Link ID: 8251 - Posted: 06.24.2010

Charlotte Schubert Exercise helps to flush a toxic molecule from the brain and causes a beneficial one to move in and protect nerve cells, research on mice shows. The discovery might help to explain why staying fit and keeping mentally active seem to fend off Alzheimer's disease in humans. "Our experiments support the idea that exercise is a good approach to all types of problems in the brain and that a sedentary lifestyle is a risk factor," says Ignacio Torres-Aleman, who led the study at the Cajal Institute in Madrid. Torres-Aleman and his colleagues were intrigued by previous studies showing that exercise slows mental decline in mice engineered to mimic Alzheimer's disease. They set out to discover the reason. They found that exercise doubled the levels of a protein that helps to flush molecules thought to underlie Alzheimer's disease out of the mice's brains and into their blood. The protein, called megalin, ejects a potentially destructive protein called amyloid-beta. In Alzheimer's patients, amyloid-beta accumulates in clumps throughout the brain. © 2004 Nature Publishing Group

Keyword: Alzheimers
Link ID: 8250 - Posted: 06.24.2010

Until West Nile virus swept through in 2002 and killed it, a murder of crows had dominated the skies around my home in northwest Washington, D.C., for more than 15 years. Their preferred roost was the roof of a house kitty-corner across the alley from my backyard. Next door, a pair of mockingbirds invariably nested in a pear tree. And every summer, at least once or twice, I watched a crow sally into the pear tree, snatch an egg or nestling from the mockingbird nest, and carry it back to the roof, seemingly oblivious to the mockingbirds' frantic distress. The parents fearlessly mobbed the cradle robber, but to no avail. Some people might have found these scenes distasteful—mockingbirds, after all, are much cuter than crows—but I miss seeing such wild displays of nature red in tooth and claw in my tame urban habitat. While urbanization has dealt a death blow to many bird species, American crows (Corvus brachyrhynchos) thrive on it. So do several of the other 45 species of birds in the widespread genus Corvus, which includes ravens, jackdaws, and the rook. (For simplicity, I'll refer to them all collectively as crows unless a distinction is in order.) At the same time, some other crow species have suffered mightily from human actions. Two species of crows that once lived in Hawaii were wiped out by the Polynesian settlers of these islands, while the third, of which a small number now exists only in captivity, was the victim of more recent habitat loss and introduced diseases. For better or worse, though, relationships between crows and people are ancient and intricate, so much so, the authors of In the Company of Crows and Ravens argue, that people influence the evolution and culture of crows and, most intriguingly, vice versa. Copyright 2005 Friends of the National Zoo.

Keyword: Intelligence; Evolution
Link ID: 8249 - Posted: 06.24.2010

A team of Spanish and American neuroscientists has discovered neurons in the mammalian brainstem that focus exclusively on new, novel sounds, helping humans and other animals ignore ongoing, predictable sounds. These "novelty detector neurons" quickly stop firing if a sound or sound pattern is repeated, but will briefly resume firing whenever some aspect of the sound changes, according to Ellen Covey, one of the authors of the study and a psychology professor at the University of Washington. The neurons can detect changes in the pitch, loudness or duration of a single sound and can even detect changes in the pattern of a complex series of sounds, she said. Covey and her colleagues, Dr. Manuel Malmierca of the University of Salamanca and doctoral student David Perez-Gonzalez, who is currently a visiting scientist in the UW psychology department, report their findings in the early December issue of the European Journal of Neuroscience. The neurons are located under the cortex in a part of the brain called the inferior colliculus. Covey said the research implies that these cells can "remember a frequently occurring pattern and perform relatively sophisticated cognitive tasks such as discriminating a novel pattern from a frequently occurring one."

Keyword: Hearing
Link ID: 8248 - Posted: 12.02.2005

The comedians are right. The science proves it. A man's brain and a woman's brain really do work differently. New research from the University of Alberta shows that men and women utilize different parts of their brains while they perform the same tasks. The results of the research are reported this month in the journal NeuroImage. The study involved volunteers who performed memory tasks, verbal tasks, visual spatial tasks and simple motor tasks while their brain activity was monitored with functional Magnetic Resonance Imaging (fMRI) technology. "The results jumped out at us," said Emily Bell, a U of A PhD student in psychiatry and lead author of the paper "Sometimes males and females would perform the same tasks and show different brain activation, and sometimes they would perform different tasks and show the same brain activation." "It is widely recognized that there are differences between males and females, but finding that different regions of the brain are activated in men and women in response to the same task has large potential implications for a variety of different clinical situations," said Dr. Peter Silverstone, a psychiatrist at the U of A and an author of the study.

Keyword: Sexual Behavior
Link ID: 8247 - Posted: 12.02.2005

Results of studies with laboratory model of PRODH deficiency demonstrate the role of COMT in compensating for overactive dopamine signaling, according to St. Jude Disruption of the normal interaction between the genes PRODH and COMT contributes directly to major symptoms of schizophrenia by upsetting the balance of the brain chemicals glutamate and dopamine, according to a group of investigators that includes a scientist now at St. Jude Children's Research Hospital. The investigators developed a model of schizophrenia that provides a way to study and understand how the loss of both PRODH and COMT gene activity contributes to the symptoms of schizophrenia. The insights they gained into the disease with this model are important because the loss of the PRODH gene causes the imbalance in the levels of both glutamate and dopamine; and this imbalance contributes directly to the symptoms of schizophrenia, according to Stanislav Zakharenko, MD, PhD, an assistant member of the Department of Developmental Neurobiology at St. Jude. The team investigated the roles of PRODH and COMT because these genes are located in the q11 region of human chromosome 22. Previous work by other scientists showed that a mutation in this region--the 22q11 microdeletion--is one of the major risk factors for developing schizophrenia.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 8246 - Posted: 12.02.2005

NO WONDER America has a growing weight problem: its children are being condemned to a life of obesity while still in the womb. According to two new studies, overeating by expectant mothers is an important but overlooked factor in the inexorable expansion of the nation's waistlines. More alarming is the conclusion of one of the new studies, from a team at Harvard Medical School, that even women who follow official advice on how much weight they should gain during pregnancy may be priming their children to become obese. In the US 16 per cent of children are classed as obese - a threefold increase since 1980. Among adults, the obesity rate is 30 per cent. That's a major concern, because obese people suffer from health problems, including heart disease, diabetes and stroke. So far, public health strategists have fought childhood fat by promoting healthy eating and exercise among children themselves. But the Harvard team, led by Matthew Gillman, and another group led by Andrea Sharma of the US Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, decided to investigate the effect of weight gain during pregnancy. Last month in Toronto, Canada, they told the third International Congress on Developmental Origins of Health and Disease that the children of women who put on a lot of weight during pregnancy were particularly prone to obesity. © Copyright Reed Business Information Ltd.

Keyword: Obesity; Development of the Brain
Link ID: 8245 - Posted: 06.24.2010