Researchers have found a drug that, in monkeys, offsets mental lapses caused by sleep deprivation without the edginess of other stimulants. The finding heightens prospects for a future pill that could restore performance in military pilots, shift workers, and others who function on minimal or irregular sleep. The drug belongs to a class of compounds called ampakines, which amplify the signal of glutamate, a neurotransmitter important for learning and memory. Unlike caffeine and other stimulants that haphazardly rev up the brain's arousal system, ampakines only work on nerve cells that are already communicating. When given the drug, rats more quickly remember where they've been, and people track moving targets with greater accuracy. However, few have considered testing the brain boosters in those who don't get enough zzz's. If not for a timely convergence, Sam Deadwyler, a neuroscientist at Wake Forest University School of Medicine in Winston-Salem, North Carolina, probably wouldn't have either. But several years ago, Deadwyler decided to merge the research tools of a collaborator with the goals of a funder. His lab had done rat experiments with ampakines made by Cortex Pharmaceuticals in Irvine, California. He also had U.S. military funds to research strategies for preventing sleep deprivation in pilots. "Well, we have this drug from Cortex," he remarked at the time. "Let's see how it works in the context of sleep deprivation." Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Sleep
Link ID: 7790 - Posted: 06.24.2010

A team of scientists at UCL (University College London) has discovered why we often miss major changes in our surroundings - such as a traffic light turning green when we're listening to the radio. Our inability to notice large changes in a visual scene is a phenomenon often exploited by magicians - but only now can scientists put their finger on the exact part of the brain that is so often deceived. The UCL team shows, in a research paper published in the September issue of the journal Cerebral Cortex (which goes online on 24th August) that the part of the brain called the parietal cortex, the area responsible for concentration, is also critical to our ability to detect changes. The exact critical spot lies just a few centimetres above and behind the right ear – the area many people scratch when concentrating. Using Transcranial Magnetic Stimulation (TMS), the team switched off the parietal cortex part of the brain temporarily by applying magnetic stimulation to the head via a magnetic coil which produces small electrical currents to the brain. Without help from this region of the brain, subjects failed to notice even major visual changes– in this case a change of a person's face.

Keyword: Vision
Link ID: 7789 - Posted: 06.24.2010

It seems that placebos have a real physical, not imagined, effect – activating the production of chemicals in the brain that relieve pain, a new study suggests. Placebos are treatments that use substances which have no active ingredient. But if people are told that what they are being given contains an active painkiller, for example, they often feel less pain – an effect that has normally been considered psychological. Recent studies, though, suggest otherwise. For example, when a placebo was secretly mixed with a drug that blocks endorphins – the body’s natural painkillers – there was no placebo effect, showing that endorphins are involved in the placebo painkiller process (New Scientist print edition, 26 May 2001, p 34). Now Jon-Kar Zubieta’s team at the University of Michigan at Ann Arbor, US, has confirmed that placebos relieve pain by boosting the release of endorphins. Fourteen healthy males in their twenties volunteered to try what they were told was “a medication that may or may not relieve pain”. To induce pain, the researchers gave the young men infusions into the jaw that made them ache. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 7788 - Posted: 06.24.2010

Researchers who used five different medical imaging techniques to study the brain activity of 764 people, including those with Alzheimer's disease, those on the brink of dementia, and healthy individuals, have found that the areas of the brain that young, healthy people use when daydreaming are the same areas that fail in people who have Alzheimer's disease. On the basis of their data, the researchers are proposing a new hypothesis that suggests that Alzheimer's disease may be due to abnormalities in the regions of the brain that operate the “default state.” This is the term used to describe the cognitive state people defer to when musing, daydreaming, or thinking to themselves. Writing in the August 24, 2005, issue of the Journal of Neuroscience, the researchers state that “the default activity patterns of the brain may, over many years, augment a metabolic- or activity-dependent cascade that participates in Alzheimer's disease pathology.” “The regions of the brain we tend to use in our default state when we are young are very similar to the regions where plaques form in older people with Alzheimer's disease,” said the lead author of the study, Randy L. Buckner, a Howard Hughes Medical Institute (HHMI) investigator at Washington University in St. Louis. “This is quite a remarkable convergence that we did not expect,” Buckner adds. © 2005 Howard Hughes Medical Institute.

Keyword: Alzheimers; Brain imaging
Link ID: 7787 - Posted: 06.24.2010

By HARRIET BROWN Two brains are better than one. At least that is the rationale for the close - sometimes too close - relationship between the human body's two brains, the one at the top of the spinal cord and the hidden but powerful brain in the gut known as the enteric nervous system. Dr. Michael D. Gershon, the author of "The Second Brain" and the chairman of the department of anatomy and cell biology at Columbia, the connection between the two can be unpleasantly clear. "Every time I call the National Institutes of Health to check on a grant proposal," Dr. Gershon said, "I become painfully aware of the influence the brain has on the gut." In fact, anyone who has ever felt butterflies in the stomach before giving a speech, a gut feeling that flies in the face of fact or a bout of intestinal urgency the night before an examination has experienced the actions of the dual nervous systems. The connection between the brains lies at the heart of many woes, physical and psychiatric. Ailments like anxiety, depression, irritable bowel syndrome, ulcers and Parkinson's disease manifest symptoms at the brain and the gut level. "The majority of patients with anxiety and depression will also have alterations of their GI function," said Dr. Emeran Mayer, professor of medicine, physiology and psychiatry at the University of California, Los Angeles. Copyright 2005 The New York Times Company

Keyword: Emotions; Stress
Link ID: 7786 - Posted: 08.23.2005

By DONALD G. McNEIL Jr. You remember Isaac Newton, his apple and the "Why didn't it fall up?" question. In the olfactory sciences, a crucial line of inquiry was opened up some years ago when a friend of a psychologist who was studying food asked, "If I hate the smell of Limburger cheese, why is it so delicious?" Researchers at Yale, the John B. Pierce Laboratory and the University of Dresden may now be closer to a biological answer. They got 11 volunteers to lie inside magnetic brain scanners with separate straws leading to the fronts of their noses (the part above the lip) and the backs (above the palate). The subjects were taught to make facial motions that closed off their palate and kept the experiment from being clouded by any sense of taste. Four odors were pumped in: butanol, farnesol (both described as "pleasantly musky"), lavender and chocolate. Only chocolate activated two different regions. Smelled from up front, it lighted up pleasure-anticipation neurons; from the back, it lighted up food-reward neurons. The scientists are unsure why only chocolate had that effect. Prof. Dana Small of the Yale team said it suggested that the brain changed smell perceptions based on eating, which is rarely done with lavender or musk. Another nasal expert, Dr. Leslie Vosshall of Rockefeller University, suggested confirmation with liver and brussels sprouts. Copyright 2005 The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 7785 - Posted: 08.23.2005

By David Reid The quest to simulate the mammalian brain on the world's most powerful supercomputer is neuroscience's most ambitious project yet. David Reid went to Lausanne in Switzerland to find out how the line is being blurred between man and machine. Inside your head nestles a forest of millions of neurons which weave together to make your thoughts. Man has long wanted to discover the secrets of the brain, and has done so with varying degrees of success. Recently advancements in this area of science have been limited by the power of computers. But at Switzerland's École Polytechnique Fédérale de Lausanne, the Blue Brain Project aims to change this by simulating the structures and functions of the brain. The project's head, Professor Henry Markram, says that in the past there was no software environment capable of simulating the brain. "We haven't had the computing power to really address the complexity of the brain. Why is the brain so complex? We need to be able to do simulations addressing the question of complexity." Now, Blue Gene, a commercially available supercomputer, will help scientists to peer into the most inscrutable part of ourselves."We are not trying to build an intelligent device or robot or anything like that," explains Professor Markram. "We are trying to understand the brain, and one pathway is to take our available knowledge of the brain and put it to a test inside a model. "That process, we believe, will reveal where our gaps are; what we do understand and what we don't understand." (C)BBC

Keyword: Intelligence
Link ID: 7784 - Posted: 08.23.2005

Being a drunk in denial can't sound much more morose than the way musician Tom Waits depicts it when he wearily growls in song, "The piano has been drinking, not me." Experts say it's this type of fuzzy headedness that makes it hard to get alcoholics to admit to the excessive behavior that's likely ruining their lives. Even when hardcore drinkers finally do leap for the back of the wagon there's usually a lot of falling off involved. Now scientists say they believe there may be even more reason to stay sober. A brain study of rats fed enough alcohol to turn them into alcoholics, shows that their brains create a new crop of brain cells in early abstinence, suggesting the brain might be repairing itself. "Months after the last dose of alcohol there are new brain cells formed… that, in fact, make more neurons in the brain and we believe that those neurons play a role in the recovery of brain function," says one of the study's authors, pharmacologist Fulton Crews, of the Bowles Center for Alcohol Studies at the University of North Carolina at Chapel Hill. Researchers bent on deciphering the anatomical workings of addiction are looking at the neuronal level because it's there that overall brain function starts. And from what researchers have seen, the damage alcohol does to neurons isn't good. "The damage to the brain that occurs in alcoholics is damage that occurs by inhibiting the repair of the brain and the normal growth of the brain, and as well as stimulating the loss of cells and neurons in the brain," says Crews. © ScienCentral, 2000-2005.

Keyword: Drug Abuse
Link ID: 7783 - Posted: 06.24.2010

ST. LOUIS -- A compound that kills cancer can sneak past the blood brain barrier, which protects the brain from foreign substances, to do its work in fighting a particularly invasive brain cancer, according to a new Saint Louis University animal study published in the Proceedings of the National Academy of Sciences Online Early Edition the week of Aug. 22. "The bottom line is, if you can get drugs into the brain, you can cure brain cancer," says William A. Banks, M.D., professor of geriatrics in the department of internal medicine and professor of pharmacological and physiological science at Saint Louis University School of Medicine and a member of the research team. The compound – JV-1-36 – is an antagonist of the hypothalamic growth hormone- releasing hormone, which has been found to cause cancerous tumors, such as malignant glioblastomas, to grow. The main known purposes of the hypothalamic growth hormone-releasing hormone usually are to trigger the hormone that makes children grow and affect how glucose is used in adults. Researchers found that the P-gp system, an extra guardian located at the blood brain barrier that usually keeps anticancer drugs out of the brain, intercepted some of the JV-1-36 that was injected into mice but let much of it pass into the brain to treat cancer.

Keyword: Miscellaneous
Link ID: 7782 - Posted: 06.24.2010

It has been known for some time that many species of birds use the Earth's magnetic field to select a direction of movement--for example, during migration. However, although such birds clearly have a sense of direction, until now it has not been possible to train birds to move in a certain direction in the laboratory, even if they are motivated by a food reward. The reasons for this failure have been perplexing, but researchers now report that they have been able to successfully accomplish this training task, providing new insight into the evolution of magnetic sensing and opening new opportunities for further study of magnetoreception. In the new work, researchers including Rafael Freire from the University of New England (Australia), Wolfgang Wiltschko and Roswitha Wiltschko from the University of Frankfurt, Germany, and Ursula Munro from the University of Technology in Sydney, demonstrated for the first time that birds could be trained to respond to a magnetic direction. The researchers trained domestic chicks to find an object that was associated with imprinting and was behind one of four screens placed in the corners of a square apparatus, and, crucially, showed that the chicks' direction of movement during searching for the hidden imprinting stimulus was influenced by shifting the magnetic field. One important difference between this work and earlier attempts to train birds is that the researchers used a social stimulus to train the birds, whereas most previous attempts have used food as the reward. The authors of the study hypothesize that in nature, birds do not use magnetic signals to find food, and tests involving such a response may be alien to them.

Keyword: Animal Migration
Link ID: 7781 - Posted: 08.23.2005

DURHAM, N.C. -- Duke University Medical Center neurobiologists have pinpointed circuitry in the brains of monkeys that assesses the level of risk in a given action. Their findings -- gained from experiments in which they gave the monkeys a chance to gamble to receive juice rewards -- could give insights into why humans compulsively engage in risky behaviors, including gambling, unsafe sex, drug use and overeating. The researchers, Michael Platt, Ph.D., and Allison McCoy, published their findings in the advanced online version of Nature Neuroscience, posted August 14, 2005. The research was sponsored by the National Institutes of Health, the EJLB Foundation, and the Klingenstein Foundation. In their experiments, the researchers gave two male rhesus macaque monkeys chances to choose to look at either of two target lights on a screen. Looking at the "safe" target light yielded the same fruit juice reward each time. However, looking at the "risky" target light might yield a larger or smaller juice reward. The average juice reward delivered by looking at either target was the same. To their surprise, the monkeys overwhelmingly preferred to gamble by looking at the risky target. This preference held, regardless of whether the scientists made the risky target reward more variable, or whether the monkeys had received more or less fruit juice during the course of the day. © 2001-2005 Duke University Medical Center

Keyword: Emotions; Drug Abuse
Link ID: 7780 - Posted: 06.24.2010

Jennifer Wild The American Psychological Association (APA) has adopted a resolution to reduce violence in children's interactive media. This follows an in-depth review confirming that violent video games can make kids aggressive in the short-term, they say. The long-term effects are still unknown. Some researchers say that playing 'shoot 'em up' video games is directly linked to kids' aggressive behaviour in the real world. Others say the games are a healthy outlet. Many say the research is so mixed that the jury is still out. That's in part because researchers have used different measures of aggressive behaviour, and different definitions of what makes for a violent game. Some have looked at physiological arousal, such as an increased heart rate, whereas others have measured violent thoughts. Not many studies have looked at violent acts. To clarify where the field stands, Kevin Kieffer and Jessica Nicoll of Saint Leo University in Saint Leo, Florida, conducted an extensive review of 17 studies conducted over 20 years. They presented their results at the 113th APA conference in Washington DC on Friday 19 August. According to their review, there's a strong link between these games and how children and adolescents behave - at least in the short term. ©2005 Nature Publishing Group

Keyword: Aggression
Link ID: 7779 - Posted: 06.24.2010

Humans are not the only conformists in the animal kingdom. New research shows that chimpanzees also tend to imitate their peers, suggesting that the human penchant for follow-the-leader may be more deeply rooted than thought. Chimpanzees have behavioural traditions that vary between groups in the wild but, so far, direct experimental evidence of how these traditions are spread and maintained has been lacking. So Andrew Whiten of St Andrews University, UK, led a team that sought to show a chimpanzee proclivity for cultural conformity in a population of captive animals. Whiten demonstrated cultural learning in chimps by introducing two different tool-use techniques to two separate groups of captive chimps at the Yerkes National Primate Research Center in Atlanta, Georgia, US. The team taught two female chimps how to get food out of a complicated apparatus using a stick. One learned to poke a barrier with the stick, and the other to lift the barrier with the stick. Then the chimps’ groups got to watch the new experts use their skills. When the rest of the groups were allowed to try their own hand at freeing the food, they followed the lead of their own expert chimp – the poker’s group preferred to poke and the lifter’s group tended to lift. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 7778 - Posted: 06.24.2010

FIONA MACGREGOR EATING just two portions of fish a week during childhood could double the risk of dying from a stroke in later life, according to a new report. The findings come after scientists reviewed the cause of death for over 4,000 people who had been part of the Boyd Orr survey on family diet and health carried out across Britain during the late 1930s. The academics from Bristol University said they could find no correlation between early eating habits and other causes of mortality, but they identified clear links between childhood diet and strokes. Dr Andy Ness of the Unit of Paediatric and Perinatal Epidemiology at the University of Bristol said: "We found that children who ate the most vegetables had a reduced risk of stroke, which ties in with the recognised benefits of vegetables, but somewhat surprisingly we found an association between fish and strokes. "There was a twofold increase in risk between those whose diet contained the most fish, at least two or three portions a week, and those who ate little or no fish." He added that the study had not aimed to identify why eating fish could lead to strokes, but called for further research. "The whole issue of fish being healthy is complicated. I would not stop my own children eating fish because of these findings, but I would probably avoid giving them fish every day." ©2005 Scotsman.com

Keyword: Stroke
Link ID: 7777 - Posted: 06.24.2010

Simon Wessely, M.D. At least until the failed attacks of July 21, the gut-wrenching shock of the July 7 suicide bombings in London had been starting to dissipate, and the nonstop news coverage was slowing. Gradually, Londoners were beginning to get on with their lives. Three days after the bombings, I joined the crowds celebrating the 60th anniversary of the end of the Second World War. The sun shone, and the Mall was full of old, proud men, wearing polished medals and fading berets. A military band gave a surprisingly good impersonation of the Glenn Miller Orchestra, and a Lancaster bomber accompanied by two Spitfires flew overhead, dropping poppies on us. The following day, England played Australia at cricket, and all seemed normal — including the resounding English defeat. True, there were more police than usual and we now had to enter the grounds by way of metal detectors, but the rituals of a London summer had returned. But what about those for whom life as usual is not going to go on? Those whose lives have been shattered by bereavement and those whose bodies were shattered by the blasts of terrorist bombs? As one emergency worker told the BBC after leaving the scene of the bombing at King's Cross station, "I don't know what heaven looks like, but I now have a good idea of hell." Many of the survivors and the bereaved are suffering intense mental anguish, an anguish that is painful for the rest of us even to witness. copyrighted © 2005 Massachusetts Medical Society.

Keyword: Stress
Link ID: 7776 - Posted: 06.24.2010

SNOWBIRD, UTAH--When it comes to which boys they'd like to date, teenage girls aren't the only ones who tend to copy each other's choices. Nature is full of species behaving like adolescent humans, and new research shows that the tendency to copy may be a heritable trait, at least in guppies. Humans and other brainy mammals often teach their young to mimic the behavior of others. Young chimps, for example, have been observed intently watching as their elders show them how to crack open nuts using rocks. Such lessons ensure that certain behaviors will be passed on to the next generation. But in shorter lived, less social animals such as fish, there aren't many teachable moments. Yet in some species, generation after generation, animals still seem to copy each other's behaviors, leaving scientists to wonder if the copying habit itself can be inherited. To test the idea, biologist Lee Dugatkin of the University of Louisville in Kentucky examined female guppies, which mimic the mate choices of their peers. After a group of female fish gave birth, Dugatkin watched the moms to see how likely they were to copy another female's mate choice. Each mom was put in a tank alone with two males in adjacent tanks on either side. Another female was placed in a tank next to one of the males, and the mom was able to watch the courtship unfold. The courting female was then removed, leaving the mom alone to make a selection. If she spent more of her time near the male "chosen" by the other female, she was a considered a copier. About 85% of the females proved to be copiers, Dugatkin found. Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 7775 - Posted: 06.24.2010

By Melanie Moran If your partner seems to be ignoring you after a flash of nudity on the television screen, it might not be his or her fault: A new psychological study finds that when people are shown violent or erotic images they frequently fail to process what they see immediately afterwards. Two studies that explore this effect, called attentional rubbernecking, were conducted by Vanderbilt University psychologist David Zald and Yale University researchers Steven Most, Marvin Chun and David Widders. The results are described in the August issue of the journal Psychonomic Bulletin and Review. “We observed that people fail to detect visual images that appeared one-fifth of a second after emotional images, whereas they can detect those images with little problem after viewing neutral images,” says Zald, assistant professor of psychology and member of the Vanderbilt Kennedy Center for Research on Human Development. Anyone who has ever slowed down to look at an accident as they are driving by – or has been stuck behind someone who has – is familiar with the “rubbernecking” effect. Even though we know we need to keep our eyes on the road, our emotions of concern, fear and curiosity cause us to stare out the window at the accident and slow to a crawl as we drive by. © 2000-2005 Vanderbilt University,

Keyword: Vision; Emotions
Link ID: 7774 - Posted: 06.24.2010

A new nasal vaccine for Alzheimer’s disease has cleared plaques from the brains of affected mice and will be tested in humans in 2006. Most previous attempts to produce a therapeutic vaccine have involved antibodies against beta amyloid, a naturally-occurring protein which is widely considered to cause the disease. In Alzheimer’s patients, beta amyloid forms plaques that seem to destroy neurons. But the antibody approach ran into problems three years ago, when a promising vaccine trial was halted after 15 of 360 volunteers developed swelling in the brain. Now Howard Weiner, at Brigham and Women’s Hospital in Boston, US, and his colleagues have tried a new strategy. Weiner was intrigued by the fact that brain inflammation in the earlier trial coincided with exceptional clearance of beta amyloid. He did some experiments and found that mice with Alzheimer’s treated to develop multiple sclerosis-like brain inflammation also cleared the beta amyloid from their brains. “Sometimes inflammation is good,” he says. His team discovered that in inducing inflammation they were activating cells in the brain known as microglia, whose job it is to ingest unwanted material. In this case, the microglia were ingesting the beta amyloid. Interestingly, in mice without beta amyloid plaques, no activation took place. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 7773 - Posted: 06.24.2010

New research published in the August 2005 issue of the American Journal of Psychiatry indicates that methamphetamine abuse and HIV infection cause significant alterations in the size of certain brain structures, and in both cases the changes may be associated with impaired cognitive functions, such as difficulties in learning new information, solving problems, maintaining attention and quickly processing information. Co-occurring methamphetamine abuse and HIV infection appears to result in greater impairment than each condition alone. "Methamphetamine abuse is linked with HIV, hepatitis C, and other sexually transmitted diseases, not only by the use of contaminated injection equipment, but also due to increased risky sexual behaviors," says Dr. Nora D. Volkow, director of the National Institute on Drug Abuse (NIDA), National Institutes of Health, which helped support the research. "These findings show that methamphetamine abuse and HIV infection each cause significant changes in the volume of brain gray matter structures and cognitive function." Scientists led by Dr. Terry Jernigan of the HIV Neurobehavioral Research Center of the University of California-San Diego conducted brain scans to analyze structural volume changes in 103 adults divided among four populations: methamphetamine abusers who were HIV-positive; methamphetamine abusers who were HIV-negative; nonabusers who were HIV-positive; and nonabusers who were HIV-negative. They also assessed the ability to think and reason using a detailed battery of tests that examined speed of information processing, attention/working memory, learning and delayed recall, abstraction/executive functioning, verbal fluency, and motor functioning.

Keyword: Drug Abuse
Link ID: 7772 - Posted: 08.12.2005

Scientists have discovered why it is that some people are chronic snorers. By carrying out head and neck scans of snorers and non-snorers, the Slovenia team found it was down to the shape of the throat. Snorers have narrower throats and the smaller the opening is, the loader the snore. Contrary to popular opinion, nasal blockages do not cause snoring though they may "amplify the loudness", the researchers told Chest journal. Dr Igor Fajdiga and his team studied 40 volunteers - 14 were non-snorers, 13 were moderately loud snorers and 13 were loud snorers, according to their spouses. How loudly people snored was directly related to the extent that their throat narrowed when they inhaled during their sleep - the narrower the throat, the bigger the snore. A culprit was the soft palate, which is the soft tissue at the back of the roof of the mouth. The snorers' soft palates were much bigger than those of non-snorers, meaning it blocked smooth airflow. Turbulent airflow is what creates the noise. When we are awake we have enough muscle tone to keep the airways open. However, when we are asleep we lose this tone. Being older and overweight can make the problem worse. (C)BBC

Keyword: Sleep
Link ID: 7771 - Posted: 08.11.2005