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

Scientists have produced evidence that the eating disorder anorexia nervosa is linked to disrupted brain chemistry. They have shown a form of the disorder is associated with an alteration of the activity of serotonin - a chemical linked to mood and anxiety. The University of Pittsburgh team hope their work could lead to the development of new drugs and psychological treatments. The study is published in Archives of General Psychiatry. The main symptom of anorexia nervosa is the relentless pursuit of thinness through self-starvation, driven by an obsessive fear of being fat. There are two sub-types. One simply involves restricting food intake, the other involves periods of restrictive eating alternated with episodes of binge eating and /or purging, rather like bulimia. The Pittsburgh team compared serotonin activity in women who had recovered from both sub-types of the disorder, with that in women who had never developed an eating disorder. Using sophisticated brain scans, they showed significantly higher serotonin activity in several parts of the brains of women who had recovered from the bulimia-type form of the disorder. Serotonin levels were also heightened in the group who had recovered from restricting-type anorexia, but not significantly so. However, the highest levels in this group were found among those women who showed most signs of anxiety. (C)BBC

Keyword: Anorexia & Bulimia; Depression
Link ID: 7883 - Posted: 09.10.2005

Jerry Avorn, M.D. The cliché "good enough for government work" implies that lower standards are acceptable for a job sponsored by a public agency. But in biomedical research, the opposite is usually true. The National Institutes of Health has always had tough standards; its newly constrained funding is leading to an even more stringent review process, so that near-perfect evaluation scores are now required to win support. Similarly stringent criteria prevail at the National Science Foundation. Yet there is one area of biomedicine in which the government allows — even defends — a minimal standard that would be unacceptable anywhere else in research. It is the set of evidentiary requirements maintained by the Food and Drug Administration (FDA) for the approval of new drugs. This is not to suggest that the FDA condones sloppiness — quite the opposite. Like a patient with obsessive–compulsive disorder, the agency is single-mindedly preoccupied with demanding the meticulous performance of a series of relatively simple acts — proving that a new medication is superior to a usually irrelevant comparison treatment (such as placebo) in achieving a potentially irrelevant outcome (such as a surrogate measure). The sloppiness resides not in the quality of execution the FDA requires, which is high, but in the questions it asks. Several drug-approval decisions illustrate the problem. Some concern the most lucrative kind of medications: those taken for extended periods by huge numbers of basically healthy people. Such "lifestyle" drugs may initially be evaluated for the treatment of a real clinical problem, such as severe obesity, but there may be no clear consensus defining the "mild" end of the disease–nondisease continuum. As a result, the market can be cranked up by aggressive promotion to both patients and prescribers. Here the comparison of a drug's benefits and risks is vitally important, but the government generally does not require such assessment. Consider the latest two "epidemics" facing Americans: overweight and insomnia. For both conditions, the application of current regulatory standards can result in important clinical and economic problems. © 2005 Massachusetts Medical Society.

Keyword: Obesity; Sleep
Link ID: 7882 - Posted: 06.24.2010

Bruce Bower When it comes to pain control, a dose of positive thinking goes a long way, according to researchers who have found that many of the same brain areas that respond to severe pain also respond to mere expectations of pain. This commonality provides a neural route for the mind to quell pain and could explain the pain-fighting power of placebos, the scientists say. "Pain emerges from the interaction between signals coming from an injured body region and cognitive information unique to each individual, such as expectations about what that pain will feel like," says neuroscientist Robert C. Coghill of Wake Forest University School of Medicine in Winston-Salem, N.C. He and his coworkers report their results in the Sept. 6 Proceedings of the National Academy of Sciences. For their study, Coghill and his colleagues recruited 10 volunteers, ages 24 to 46, and fitted each with a device that delivered heat pulses to the lower right leg. In a training session, the researchers taught participants to expect one of three intensities of painful heat, depending on the delay between a tone and the jolt. A 7-second interval signaled heat that caused mild pain, a 15-second wait heralded heat that produced moderate pain, and a 30-second gap indicated heat resulting in pronounced pain. Copyright ©2005 Science Service.

Keyword: Pain & Touch
Link ID: 7881 - Posted: 06.24.2010

By NICHOLAS WADE Two genes involved in determining the size of the human brain have undergone substantial evolution in the last 60,000 years, researchers say, leading to the surprising suggestion that the brain is still undergoing rapid evolution. The discovery adds weight to the view that human evolution is still a work in progress, since previous instances of recent genetic change have come to light in genes that defend against disease and confer the ability to digest milk in adulthood. It had been widely assumed until recently that human evolution more or less stopped 50,000 years ago. The new finding, reported in today's issue of Science by Bruce T. Lahn of the University of Chicago, and colleagues, could raise controversy because of the genes' role in determining brain size. New versions of the genes, or alleles as geneticists call them, appear to have spread because they enhanced brain function in some way, the report suggests, and they are more common in some populations than others. But several experts strongly criticized this aspect of the finding, saying it was far from clear that the new alleles conferred any cognitive advantage or had spread for that reason. Many genes have more than one role in the body, and the new alleles could have been favored for some other reason, these experts said, such as if they increased resistance to disease. Copyright 2005 The New York Times Company

Keyword: Evolution
Link ID: 7880 - Posted: 09.09.2005

BABY chimpanzees express emotion by smiling and pulling faces just like human infants, researchers have found. A study of 37 chimps in their first months of life at a US research centre revealed striking similarities with humans. All smiled to show happiness within the first three weeks of birth, said Dr Kim Bard from the University of Portsmouth. Infants tended to smile when they were placed face-to-face with a human examiner. They also uttered vocal greetings. Like human babies, they imitated carers who opened their mouths and stuck out their tongues. They were also able to imitate a sequence of sounds within the first weeks of life. Chimps who were kept in an environment where carers responded to their emotional needs were more communicative. But they also became angry when the help they came to expect was not forthcoming. ©2005 Scotsman.com

Keyword: Evolution; Development of the Brain
Link ID: 7879 - Posted: 06.24.2010

Like many students, MIT graduate student Gauri Nanda often has a hard time waking up for class. "I've had lots of trouble getting out of bed. Sometimes I'll hit the snooze button for two hours," Nanda says. So as part of a class project, she created an alarm clock — "clocky" — that you have to get out of bed and chase before you can turn it off. "It will fall to the floor and sort of roam around until he finds a place to hide," she explains. "[It] sort of ensures that you wake up in the morning, because you have to use more of your senses before you can actually turn the alarm off." Neuroscientist Masashi Yanagisawa says this approach has scientific merit because getting up wakes you up. "The best way to wake up in the morning is, as soon as you hear the alarm clock goes off, you get up and start to be physically or mentally active, rather than keep pushing the snooze button," explains Yanagisawa, who studies the molecular genetics of our brains at the University of Texas Southwestern Medical Center at Dallas and the Howard Hughes Medical Institute. Our brains have brain cells, or neurons, that produce a protein called orexin. "They are so to speak our 'wake-up neurons,'" Yanagisawa says. "So we need those neurons to be firing very fast in order to maintain wakefulness during day time." Without these brain cells functioning and pumping out orexin people just can't stay awake — they suffer from narcolepsy. "Those patients cannot keep themselves awake during day time in a socially and physically appropriate manner," he says. © ScienCentral, 2000-2005.

Keyword: Sleep
Link ID: 7878 - Posted: 06.24.2010

Male and female fruit flies, like men and women, tend to behave quite differently — particularly during courtship. When trying to find a mate, the male fruit fly performs an elaborate courtship dance packed full of abdomen tapping and wing-beating serenades, while the female looks on. But even though males and females look different (and most of us would say certainly think differently), certainly our eyes, ears, and noses perceive things the same way. Or do they? "Just like in people, we'd always inferred that the male and female fly perceived the world the same," explains Stanford University geneticist Bruce Baker. "But, in fact, we now see, at a molecular level, that those sense organs are not the same, and so it may well be the case that… males and females don't sense the same world." Baker and his research team have been working to try and understand why animals behave as they do, particularly the kinds of innate behaviors that animals just seem to know how to do. "Things like the kind of nest a bird will build; the kind of courtship display that a male peacock might make," he says. "We'd like to understand what happens during development to give an organism the potential to do these often amazing and wonderful sorts of behaviors that they carry out." They discovered a gene that triggers mating behavior in male fruit flies, whose elaborate mating ritual involves all the senses, from smell and taste, to the sound of the courtship song he plays for his beloved. © ScienCentral, 2000-2005.

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 7877 - Posted: 06.24.2010

By Larry O'Hanlon, Discovery News — Bumblebees are a brainy bunch, according to new study showing that the insects watch other bumblebees to learn what flowers to dine on. The ability to learn simply by watching is usually accorded to only certain birds, marine mammals and primates. This new work shows that the old saying "monkey see, monkey do" applies even to some insects. "Bees can learn things on their own or learn from others," said bumblebee researcher Bradley Worden of the University of Arizona. Worden is a co-author of a paper on the matter in an upcoming issue of Biology Letters of the Royal Society. To test the learning skills of bumblebees, Worden and his colleagues set up a glassed-off watching station where bumbles could observe other bees feeding at different flowers. The feeding bees were previously trained to prefer nectar from certain colored artificial flowers. "It's purely observational, without a reward," said Worden, making the distinction between the training commonly used to train dogs and other animals. Afterwards, fresh flowers of the same kinds were made available to the observer bumblebees. The observer bees immediately showed a distinct preference for the kinds of they had seen other bees dining from. Copyright © 2005 Discovery Communications Inc.

Keyword: Learning & Memory; Evolution
Link ID: 7876 - Posted: 06.24.2010