Previous research has shown that alcohol-use disorders (AUDs) are associated with abnormalities of the prefrontal cortex, thalamus and the cerebellar hemispheres in adults. These same brain structures are known to be actively maturing during adolescence. An examination of adolescents and young adults with AUDs has found that a smaller prefrontal cortex is associated with early-onset drinking. Results are published in the September issue of Alcoholism: Clinical & Experimental Research. "This is the first study to examine the sizes of these brain structures in adolescents and young adults," said Michael D. De Bellis, professor of psychiatry and behavioral sciences and director of the Healthy Childhood Brain Development Research Program at Duke University Medical Center, as well as corresponding author for the study. "Studies on adults with alcoholism have generally shown smaller brain sizes, but this is after many years of very heavy drinking," added Susan Tapert, associate professor of psychiatry at the University of California at San Diego. "Before this study, it really wasn't clear that adolescents, with briefer drinking histories, would show any differences in brain size. However, with nearly one in three high-school seniors binge drinking at least once per month, it is critical that we understand precisely how drinking affects the brain of these young people."

Keyword: Drug Abuse; Development of the Brain
Link ID: 7903 - Posted: 09.15.2005

For recovering addicts, the sight of drug paraphernalia and other reminders can trigger intense cravings and relapses. Now, two studies with rats demonstrate that it's possible to weaken drug-related memories by interfering with molecular signals in the brain's reward pathways. The work is a long way from the clinic, but researchers say it hints at an exciting new approach to helping addicts kick the habit. Both studies, published in the 15 September issue of Neuron, add to growing support for a process called memory reconsolidation. This controversial idea holds that each time a memory is recalled it becomes briefly vulnerable--and can be weakened by compounds that target certain genes or molecules in the brain. To find out whether drug-related memories can be weakened during recall, Jonathan Lee and colleagues at the University of Cambridge, U.K., first introduced a group of rats to the pleasures of cocaine. The animals quickly learned that a glowing light appeared each time they scored a hit. When the rats subsequently visited a different chamber, they busily pressed a lever that turned on the light, even if no cocaine was forthcoming. © 2005 by the American Association for the Advancement of Science.

Keyword: Drug Abuse; Learning & Memory
Link ID: 7902 - Posted: 06.24.2010

MADISON - In a study of adult monkeys who were exposed to moderate amounts of alcohol in utero, scientists have found that prenatal exposure to alcohol - even in small doses - has pronounced effects on the development and function later in life of the brain's dopamine system, a critical component of the central nervous system that regulates many regions of the brain. Writing in the current issue (Sept. 15, 2005) of the journal Alcoholism: Clinical and Experimental Research, a team of researchers led by Mary L. Schneider, a University of Wisconsin-Madison professor of occupational therapy and psychology, reports that when a monkey exposes her fetus to alcohol by drinking, the dopamine system of her offspring is altered. Effects on that key neural system, according to the study's results, can manifest themselves up to five years after birth, when the monkeys are fully grown. The influence of alcohol on the dopamine system, depending on the timing of exposure during gestation, varies, says Schneider, but illustrates yet another biological consequence of drinking while pregnant. "It appears that there is no safe time to drink," says the Wisconsin researcher. "And because our study looked at the effects of lower doses of alcohol than most previous studies, the results suggest there is no safe amount of alcohol that can be consumed during pregnancy. Even moderate drinking can have effects that persist to adulthood."

Keyword: Drug Abuse; Development of the Brain
Link ID: 7901 - Posted: 09.15.2005

Andreas von Bubnoff Sharing the same sexual partner with your mother or grandmother may sound odd, but female greater horseshoe bats (Rhinolophus ferrumequinum) in Britain do it all the time. This ensures that the bats in the colony are closely related to each other, says Stephen Rossiter at Queen Mary, University of London, lead author of a study appearing this week in Nature1. Researchers believe that such close family ties encourage cooperation, such as food sharing, between colony members. But although related females share mates, they manage to avoid the genetic pitfalls of inbreeding, the researchers found. Rossiter's team studied a colony of 45 female bats living in the attic of Woodchester Mansion in Gloucestershire, UK, over a period of ten years. In that time they found a much higher rate of related female bats sharing partners than expected: 11 pairs of mothers and daughters shared mates at least once, for example, along with 7 pairs of grandmothers and granddaughters. Yet amidst all this partnering, there was only one case of a female mating with her own father. How the females avoid mating with close relatives is unclear; they might use smell as a cue, Rossiter says. ©2005 Nature Publishing Group

Keyword: Sexual Behavior; Evolution
Link ID: 7900 - Posted: 06.24.2010

PORTLAND, Ore. - Some people call it "the dark time," the period between when a person is diagnosed with Parkinson's disease and when treatment with medication begins. Julie Carter, R.N., knows it all too well. The associate professor of neurology in the Oregon Health & Science University School of Medicine hosts workshops to help newly diagnosed Parkinson's patients and their families cope with the prospect of fighting a chronic, degenerative, incurable neurological disease the rest of their lives. "Some people say it's like looking through a picture window and someone comes along and shatters it," said Carter, associate director of the OHSU Parkinson Center of Oregon, which runs the workshops. "Patients are told they're not ready for medication and to come back in six months. But in these early stages, what you're really dealing with is a diagnosis. You're dealing with a fear of what the future will hold." And there is a lot that can be done to treat Parkinson's patients, in the early months and beyond. So says an article by John "Jay" G. Nutt, M.D., professor of neurology, and physiology and pharmacology, OHSU School of Medicine, and director of the Parkinson center. The article appearing in the Thursday, Sept. 8, edition of the New England Journal of Medicine outlines reliable, evidence-based strategies for general practitioners to effectively and confidently diagnose Parkinson's, and suggest ways patients and their caregivers can initially manage the disease.

Keyword: Parkinsons
Link ID: 7899 - Posted: 09.15.2005

By PETER C. BELLER Josh Bedwell was deep into his third year at Mount Sinai School of Medicine before he got up the nerve to ask a resident for permission to go home. After 7 a.m. rounds and a lunchtime class, Mr. Bedwell often found himself stuck at the hospital with nothing to do. Dr. Josh Bedwell, a former student at Mount Sinai School of Medicine, said students would often put in long hours at the hospital doing little. "You sit there until the resident is like 'Oh, you're still here? You should go home.' That gets really old," said Dr. Bedwell, 25, now a surgical intern at Beth Israel Medical Center. While sleep deprivation and long workdays are deemed rites of passage for medical students, there is growing concern among medical educators that students may be spending excessive hours in hospitals doing work of little educational value, to the detriment of their education and health. In a recent survey by the American Medical Association, one in four students said lack of sleep had put them in physical danger and one in six reported having or nearly having a car accident because of sleep deprivation. Two-thirds said fatigue might have affected their learning. As a result, medical schools and the bodies that set policy for medical education are debating whether medical students should have strict guidelines similar to those that limit the hours medical residents can work. Copyright 2005 The New York Times Company

Keyword: Sleep
Link ID: 7898 - Posted: 09.14.2005

by Julian Baggini 256pp, Granta, £14.99 Do you remember having a rather disturbed night's sleep about a month ago? That was the night I stole your brain. After landing my flying saucer in your garden, I crept into your bedroom and surgically removed your sleeping brain. I whisked it to my laboratory back on Pluto and connected it up to a supercomputer running a virtual-Earth program. This computer is currently feeding into your brain the same patterns of electrical stimulation that used to be produced by your sense organs, when you still had some. So it seems to you as though you're still on Earth. But everything you seem to observe around you, including this newspaper, is actually virtual. You've been brain-snatched. How can you tell this hasn't happened: that what you're experiencing now isn't virtual? It seems you can't. But if you can't tell whether this newspaper is real or virtual, then how can you be said to know it's real? This is a famous philosophical thought experiment. In just a few sentences, it seems to demolish something we would ordinarily take entirely for granted: our knowledge of the world around us. Thought experiments can induce an overwhelming sense of intellectual vertigo. What we thought was the firm ground beneath our feet suddenly crumbles and we're left dangling over a void. © Guardian Newspapers Limited 2005

Keyword: Miscellaneous
Link ID: 7897 - Posted: 06.24.2010

Kaley Terre Haute, Ind. Robert Heinsohn, professor of evolutionary biology at the Australian National University, explains. Males are more colorful or ornamented than females in most, but not all, bird species. Understanding this phenomenon requires a basic grasp of the evolutionary forces that shape the behavior and morphology of individuals and species. Charles Darwin developed much of the theory that helps explain this. He proposed that traits promoting survival in individuals are favored by the process of natural selection, whereas traits that help the individuals of just one sex (usually the males) compete for mates are favored by sexual selection. Sexual selection is responsible for many of the features unique to one sex in a given species. These features can be divided into two general categories: those acting as weapons that allow males to fight for access to females (antlers on deer, for example) and those acting as ornaments that attract the attention of females, such as long tails on birds. Darwin concluded that color differences between sexes in birds (also known as sexual dichromatism) result largely from female preference for bright colors in males. This general rule has received much support since Darwin's time, but other influences have also been noted. For example, females of species that are exposed to predators while incubating tend to have dull colors, although both sexes may be brightly colored in species that nest in tree hollows because the females are less visible to predators. Color can also aid individuals in recognizing members of their own species. And in species that are not good to eat, colors can provide a warning to potential predators. © 1996-2005 Scientific American, Inc.

Keyword: Sexual Behavior; Evolution
Link ID: 7896 - Posted: 06.24.2010

A new study reveals critical molecular events in the origin of fat cells. The findings are central to understanding chronic diseases, such as obesity and diabetes, as fat cells produce hormones critical for metabolic control, the researchers said. The study finds that a hormonal cocktail routinely used in the lab induces a key genetic switch in the transition from fat-cell precursors to full-blown fat, researchers at University of Michigan Life Sciences Institute report in the September Cell Metabolism. "The body needs fat cells, both as a storage depot for fuel and as cells that sense hormonal and energy status and in response, secrete hormones that maintain whole-body energy balance," said study author Alan Saltiel. "However, you don't want too many, big fat cells. It's a careful balance, and many diseases are associated with either extreme." Lipodystrophies are disorders characterized by fat deficiency, Saltiel said. While obesity and lipodystrophy represent opposite ends of the spectrum, both are characterized by other metabolic disorders, such as insulin resistance, he added.

Keyword: Obesity
Link ID: 7895 - Posted: 09.14.2005

By Larry O'Hanlon, Discovery News —Namibian elephants really know the airwaves, say researchers who have discovered that the big mammals prefer to broadcast their very low-frequency calls at exactly the times of day when the air is best for carrying sound a long way. In a three-week study that incorporated a range of meteorological equipment and an array of eight microphones, 42 percent of all elephant calls were made during the stable air period three hours after sunset. The next most popular calling time during the two hours after sunrise, also a time when the acoustics of the atmosphere are the best for carrying calls great distances. "This project was an attempt to demonstrate in the field predictions we had made with mathematical, acoustical models," said Michael Garstang of the University of Virginia. A paper co-authored by Garstang, reporting the results of the work, appears in the current issue of the journal Earth Interactions. Of about 1,300 calls recorded during the study, 94 percent fell within those two time periods, he said. © 2005 Discovery Communications Inc.

Keyword: Hearing; Animal Communication
Link ID: 7894 - Posted: 06.24.2010

By Sandra G. Boodman A few days after the terrorist attacks of 2001, mental health experts descended on New York, poised to help residents cope with a wave of psychiatric problems that never materialized. But experts in disaster psychiatry predict that the repercussions from Hurricane Katrina, a catastrophe without parallel in modern American history, are likely to be far greater and to last for years. "This is unprecedented," said New York psychiatrist Spencer Eth, who was involved in treating survivors of the World Trade Center attack, which unlike the hurricane, killed many victims at the scene and destroyed several office towers, not entire communities. "People are not going to bounce back and resume their lives and recover" at the pace seen after other disasters, Eth predicted. The previous disasters on which experts rely for lessons about how to handle the victims of mass tragedy -- plane crashes, earthquakes and hurricanes including Andrew, which struck Florida in 1992; the bombing of the Oklahoma City federal building in 1995; the attacks of Sept. 11, 2001 -- are all dwarfed by the devastation wrought by Katrina. © Copyright 1996-2005 The Washington Post Company

Keyword: Stress; Depression
Link ID: 7893 - Posted: 06.24.2010

By ANAHAD O'CONNOR THE FACTS It's 1 a.m., and you wake up to find someone you know quietly wandering around the house - eyes open but appearing dazed. Should you wake the person? Some people give credence to the adage that rousing a sleepwalker can give him a heart attack. But experts say it's highly unlikely. Dr. Ana C. Krieger, the director of the Sleep Disorders Center at New York University, said the myth probably started because of sleepwalkers' response when they're awakened. Many are confused and terrified, having no idea how they ended up in a dark closet or gliding down a hallway. "At that point, they might not even recognize relatives," Dr. Krieger said. "If this is a well-known friend or child, and the person wakes up and is saying, 'Get me out of here! Who are you?' it can be very frightening." She recommends guiding the person back to bed by an arm or elbow. Researchers are not sure what brings on sleepwalking, but it's known that it occurs during the deepest and most restful stages of sleep. As people age, the amount of time they spend in these stages decreases sharply, explaining why children are more likely to sleepwalk than adults. Copyright 2005 The New York Times Company

Keyword: Sleep
Link ID: 7892 - Posted: 09.13.2005

By JANE E. BRODY A serious dispute over vitamins should concern every woman of childbearing age who wants to protect her unborn child against a serious and sometimes fatal birth defect of the spine or brain. And not just women who are planning to become pregnant. Half of all pregnancies in this country are unplanned, so every woman who could become pregnant - including teenage girls, many of whom fail to anticipate having sex, let alone becoming pregnant - should act now to prevent these defects. The battle involves the B vitamin folic acid, which aids in the normal development of a baby's neural tube, the part that becomes the brain and spinal cord. Neural tube development takes place three to four weeks after conception, before many women know they are pregnant. And since it can take a while to build up protective blood levels of folic acid, it is necessary to have enough folic acid on board when a woman conceives and through the first three months of pregnancy for maximum protection against neural tube defects. These defects are among the most common serious birth defects. They include spina bifida, an often crippling failure of the spine and back bones to close fully, and anencephaly, a fatal failure of the brain and skull to form properly. Copyright 2005 The New York Times Company

Keyword: Development of the Brain
Link ID: 7891 - Posted: 09.13.2005

BUFFALO, N.Y. -- Neuroscientists at the University at Buffalo have shown in two recently published papers that destabilization of structures called microtubules, intracellular highways that transport receptors to their working sites in the brain, likely underlie many mental disorders and could be promising targets for intervention. In their most recent article, published in the Aug. 19 issue of the Journal of Biological Chemistry, they report that destabilization of microtubules interferes with the action of the NMDA receptor, a target of the neurotransmitter glutamate, which plays a critical role in learning and memory. "You can think of NMDAR as the cargo moving along a railway consisting of the microtubules cytoskeleton," said lead author Eunice Yuen, graduate student in the laboratory of Zhen Yan, Ph.D., associate professor in the Department of Physiology and Biophysics, UB School of Medicine and Biomedical Sciences. "Microtubules are hollow cylinders made up of polymers of the protein tubulin," she said. "Agents that break up, or depolymerize, microtubules disrupt the railway, stop the traffic and reduce the number of cargoes that get delivered to the neuronal surface.

Keyword: Learning & Memory
Link ID: 7890 - Posted: 09.13.2005

— Taste, like beauty, truly is in the brain of the beholder, varying, sometimes dramatically, from one person to the next, according to one of the world's leading sensory neurobiologists. "No two people will ever smell the same thing in the same way," said Patrick Mac Leod, president of the Institute of Taste and former director of the sensory neurobiology laboratory at the Ecole Pratique des Hautes Etudes. "When we perceive an odor, the exact nature of the sensation that is produced depends as much on the observer as the object," he told AFP. Vision, hearing and tactile perception are far more uniform across the species, meaning that human beings see, hear and touch more or less the same things. But when it comes to odors and taste, one person's wine-of-the-gods can be another's plonk. This and other recent findings in sensory neurobiology, said Mac Leod, upend a lot of received wisdom and a fair amount of established science. They also carry profound implications for a host of consumer-oriented industries ranging from food and wine to perfumes and household products. © 2005 Discovery Communications Inc.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 7889 - Posted: 06.24.2010

Roxanne Khamsi Women who take the contraceptive pill cut their short-term risk of developing multiple sclerosis by nearly half, according to a survey. The study suggests that the pill could help delay onset of the debilitating neurodegenerative disease. Birth-control pills contain oestrogen, one of the most significant female reproductive hormones. The compound, whether produced naturally or taken as a pill, helps to regulate the menstrual cycle. The survey's discovery adds to a range of positive effects that oestrogen has on non-reproductive organs. The hormone seems, for example, to stop bone loss and forestall heart disease. It can provide relief from hot flushes and may even protect against cognitive decline, although studies linking cancer with hormone-replacement therapy in post-menopausal women have recently curbed medical experts' enthusiasm for oestrogen-containing drugs. Roughly two-thirds of multiple-sclerosis patients are female, and women generally have higher levels of oestrogen than men. So the disease has been blamed on the hormone in the past, explains Alvaro Alonso of Harvard School of Public Health in Boston, Massachusetts, who led the recent study. In fact, some doctors warn women with a family history of multiple sclerosis not to take the pill. ©2005 Nature Publishing Group

Keyword: Multiple Sclerosis; Hormones & Behavior
Link ID: 7888 - Posted: 06.24.2010

New Haven, Conn.-Yale School of Medicine researchers published a report this month in the Archives of General Psychiatry that highlights the interplay of two brain signaling systems, glutamate and dopamine, in psychosis and cognitive function. The study helps resolve a long-standing research debate between the "dopamine hypothesis" and the "glutamate hypothesis" or "PCP Model," said John Krystal, M.D., professor, deputy chair for research in the Department of Psychiatry, and lead author of the study. "Both systems appear to be involved," he said. The first theory suggests that dopamine neurons are hyperactive in persons with schizophrenia and that effects of the dopamine-releasing drug, amphetamine, can mimic aspects of the illness. The second theory maintains that certain schizophrenia-related deficits in the function of glutamate, the dominant stimulatory transmitter, could be reproduced in healthy people by the administration of drugs such as ketamine, which block the NMDA subtype of glutamate receptors. The study included 41 healthy subjects who were given amphetamine, ketamine and then saline, in varying sequence. The researchers found the transient psychotic state produced by each drug was similar but not identical and that ketamine produced a more "complete" schizophrenia-like state than amphetamine. They also found that cognitive impairments produced by ketamine, specifically working memory, were reduced by the administration of amphetamine.

Keyword: Schizophrenia
Link ID: 7887 - Posted: 09.13.2005

By LISA SANDERS, M.D. The man squinted into the morning mist as he leaned forward to place his ball on the first tee of the golf course. The motion triggered an explosion of pain. "There was a huge bang in my head," he later told the neurologist, the third doctor he had seen in the two months since that Friday morning. "The pain was tremendous," the patient, himself a doctor, said. "I could barely get out of bed the entire weekend." On Monday the doctor-patient ordered a CT scan of his head. He was making rounds on his own patients in the hospital that morning when the radiologist called. He'd seen something on the CT. Behind the forehead, there were two small pockets of fluid where normally there is none. These pockets can have many causes but most commonly are the remnants of a bruise in the brain that is healing. The patient considered himself a healthy man. He was 51 and had normal blood pressure and an enviable cholesterol level. He neither smoked nor drank. He had just started working out - a half an hour on the treadmill and some light weights for upper-body strength. And that's when all the trouble started. He had been going to the gym for maybe a week when he developed severe neck pain. He figured it was a sprain or even a slipped disc and treated himself with heat packs and lots of ibuprofen. The neck pain eased but it was replaced by strange, intense headaches, which came on suddenly, when he moved his head a certain way. Leaning over caused the worst pain. The headaches lasted minutes, sometimes a couple of hours - but that morning on the golf course, the pain had struck like a clap of thunder and lasted for days. Copyright 2005 The New York Times Company

Keyword: Pain & Touch
Link ID: 7886 - Posted: 09.12.2005

Berkeley -- The short-term memory problems that accompany normal aging are associated with an inability to filter out surrounding distractions, not problems with focusing attention, according to a study by researchers at the University of California, Berkeley. Although older patients often report difficulty tuning out distractions, this is the first hard evidence from functional magnetic resonance imaging (fMRI) studies of the brain that memory failure owes more to interference from irrelevant information than to an inability to focus on relevant information. "Difficulty filtering out distractions impacts a wide range of daily life activities, such as driving, social interactions and reading, and can greatly affect quality of life," said study leader Dr. Adam Gazzaley, adjunct assistant professor of neuroscience at UC Berkeley and a newly appointed assistant professor of neurology and physiology at UC San Francisco. "These results reveal that efficiently focusing on relevant information is not enough to ensure successful memory," he said. "It is also necessary to filter distractions. Otherwise, our capacity-limited short-term memory system will be overloaded."

Keyword: Alzheimers; Learning & Memory
Link ID: 7885 - Posted: 09.12.2005

Clioquinol, an antibiotic that was banned for internal use in the United States in 1971 but is still used in topical applications, appears to block the genetic action of Huntington's disease in mice and in cell culture, according to a study reported by San Francisco VA Medical Center (SFVAMC) researchers. The study, led by principal investigator Stephen M. Massa, MD, PhD, a neurologist at SFVAMC, was reported in the August 16, 2005 issue of Proceedings of the National Academy of Sciences. Huntington's disease is a hereditary, degenerative, and ultimately fatal disease of the brain that causes changes in personality, progressive loss of memory and cognitive ability, and a characteristic uncontrolled jerking motion known as Huntington's chorea. There is no known cure or effective treatment. A person who carries the mutant Huntington's gene may pass it on unknowingly because the disease often manifests in early to late middle age after the carrier's children have already been born. During the course of the disease, the Huntington's gene causes the production of a toxic protein, mutant huntingtin, in neurons (brain cells). Eventually the protein kills the neurons, causing the disease's degenerative effects. In Massa's study, Clioquinol appeared to interrupt the production of mutant huntingtin. In the first part of his study, Massa and his research team tested the effect of Clioquinol on neurons in cell culture that contained a form of the mutant Huntington's gene.

Keyword: Huntingtons
Link ID: 7884 - Posted: 09.12.2005