By Susan Milius Let’s take a minute to turn faces upside down. Pick any face. Ignore beards, glasses, hairdos or lack of any hair to do, and upend the facial features of Charles Darwin, Ray Charles or anyone named Charlotte who reads Science News. People who normally remember or match a face perfectly well have trouble when it is standing on its head. But before there’s a chorus of “well, obviously,” let’s try turning dogs upside down, too. Most people who don’t breed dogs or judge shows don’t recognize an individual dog nearly as well as a person’s face to begin with. And when pictures of poodles and Irish setters flip upside down in quizzes of learning and memory, people struggle a bit more than they do with the natural versions. But scores drop only modestly with these flipped-dog pics, compared with the dramatic drop for facial flips. The disproportionate decline in remembering inverted faces has shown up in a variety of recall tests, with comparison groups from dogs to bridges, airplanes, stick figures, even clothing from 17th and 18th century paintings. Upside-down faces are where quiz scores really slump, and researchers view that slump as one of the signs that test-takers are actually experts at face perception. A dog is a dog in any orientation. Same for other organisms and objects. But right-side-up faces apparently are so compelling that people have become especially masterful at recognizing the human visage. Know-it-at-a-glance holistic techniques behind this mastery fail when the world turns upside down. access © Society for Science & the Public 2000 - 2012

Keyword: Attention; Evolution
Link ID: 17291 - Posted: 09.22.2012

by Virginia Morell Bumblebees foraging in flowers for nectar are like salesmen traveling between towns: Both seek the optimal route to minimize their travel costs. Mathematicians call this the "traveling salesman problem," in which scientists try to calculate the shortest possible route given a theoretical arrangement of cities. Bumblebees, however, take the brute-force approach: For them, it's simply a matter of experience, plus trial and error, scientists report in the current issue of PLoS Biology. The study, the first to track the movements of bumblebees in the field, also suggests that bumblebees aren't using cognitive maps—mental recreations of their environments—as some scientists have suggested, but rather are learning and remembering the distances and directions that need to be flown to find their way from nest to field to home again. A team of researchers from Queen Mary, University of London outfitted seven bumblebees with tiny radar transponders, which they stuck on the bees' backs with double-sided tape. They trained the bees to forage nectar from five blue artificial flowers (see video). Each artificial flower had a yellow landing platform and a single drop of sucrose, just enough to fill one-fifth of a bumblebee's tank capacity, to ensure that the bees would visit all five flowers on each foraging bout. The scientists placed the flowers in a field at Rothamsted Research, a biological research station north of London, in October—a time of year when there are few natural sources of nectar and pollen and the bees are more likely to focus on the artificial flowers. They arranged the flowers in a pentagon and spaced them 50 meters apart; that distance is more than three times as far as bumblebees can see, so the bees must actively fly around to locate their next target. A motion-triggered Webcam was attached to each flower to record the bees' visits. Then, every day for a month, each bee was freed to forage for 7 hours. © 2010 American Association for the Advancement of Science

Keyword: Animal Migration; Evolution
Link ID: 17290 - Posted: 09.22.2012

By Gary Stix Neuroscientists have devoted inordinate energy in recent years to publicize the need for, not only gene maps, but for a full wiring diagram of all brain circuits. The benefits of a connectome as it is known might yield new understanding that could eventually result in pharmaceuticals for intractable psychiatric disorders. This ultimate neural network might even divvy up intimations of the workings of consciousness. The futurist contingent, many of whom began careers hacking computers not neural circuity, has speculated that a whole brain blueprint of you or me might be copied to a hard drive so that we can live for a digital eternity like Max Headroom. Christof Koch, the chief scientist at the Allen Institute for Brain Science, the organization that produced the gene map, dismissed facile optimism about the prospects for these scenarios with a commentary in Science last month. In it, he calculated that it could take 2000 years to analyze all of the possible interactions among the 1,000 different proteins that populate a single synapse. Koch then went on to speculate about a way of reducing the complexity of such calculations. The question still remains of how we will know when we have actually started to make sense of the tangle of wiring that populates the deepest recesses inside our skulls. One plausible answer: when the FDA approves a new drug that fundamentally advances treatment of schizophrenia, the psychiatric illness that has aberrant effects on a multitude of neural pathways—an iconic example of the brain’s underlying complexity. © 2012 Scientific American

Keyword: Schizophrenia
Link ID: 17289 - Posted: 09.22.2012

The human brain is big and complicated. There has been a map for gene expression in mice brains available for a number of years but human brains are a thousand times bigger and a little harder to come by for post-mortem research. But published today is a high-resolution 3D atlas of the human brain created by an international team led by Michael Hawrylycz of the Allen Institute for Brain Science in Seattle. The project was launched in March 2008 with a budget of $55 million. Working with just two whole male brains and a single hemisphere from a third, the team used around 900 precise subdivisions and 60,000 gene expression probes to create the atlas. This image is a 3D rendering of just one of the genes in internal brain structures overlaid onto an MRI scan. The level of gene expression at the different points on the map is indicated on a colour scale, with blue dots reflecting relatively low expression and red dots reflecting high expression. The aim of the project is to provide a platform for further study into gene expression in the brain and how it is involved in normal and abnormal brain function. The Allen Brain Atlas is freely accessible online. Journal reference: Nature, DOI: 10.1038/nature11405 © Copyright Reed Business Information Ltd.

Keyword: Brain imaging; Genes & Behavior
Link ID: 17288 - Posted: 09.22.2012

By Janet Raloff Most people would never equate downing a well-dressed salad or a fried chicken thigh with toking a joint of marijuana. But to Joseph Hibbeln of the National Institutes of Health, the comparison isn’t a big stretch. New animal experiments by Hibbeln and his colleagues have recently shown that the body uses a major constituent in most vegetable oils to make its own versions of the psychoactive ingredient in marijuana. Called endocannabinoids, these natural compounds play a role in heightening appetite. So overproducing them unnecessarily boosts hunger, similarly to how pot triggers the munchies (SN: 6/19/10, p. 16). If what happens in people mirrors what happens in animals, then the prevalence of soybean oil, corn oil and other polyunsaturated vegetable oils in today’s Western diet means your body is “dumping out a lot of these marijuana-like molecules into your brain,” explains Hibbeln, a nutritional neuroscientist. “You’re chronically a little bit stoned.” Vegetable oil’s link to endocannabinoids is just one example of newfound and surprising ways that foods can confuse calorie-sensing networks and foster obesity — in some cases by damaging the brain. Especially troubling: Excess body weight itself can exaggerate the risk of the brain telling a well-fueled body that it is running on empty. By understanding what messes with the body’s satiety meters and why, scientists hope to identify tactics for reducing a diner’s likelihood of becoming another statistic in the obesity epidemic. © Society for Science & the Public 2000 - 2012

Keyword: Obesity; Drug Abuse
Link ID: 17287 - Posted: 09.22.2012

By RONI CARYN RABIN Amid fervid criticism that New York City risks becoming a nanny state, city health officials this month banned the sale of supersize sugar-laden drinks in restaurants and movie theaters. Now scientists have handed the ban’s advocates a potent weapon: strong evidence that replacing sugared drinks with sugar-free substitutes or water really can slow weight gain in children. Two-thirds of all American adults and one-third of children in the United States are overweight or obese. The contribution of sugary sodas and fruit drinks to this epidemic has been hotly disputed. But two new randomized clinical trials published on Friday in The New England Journal of Medicine lend credence to the idea that limiting access to these beverages may help reduce obesity. Beverage industry officials denounced the research, which may fuel wider efforts to curb consumption through taxes or other restrictions. In one of the new trials, researchers at Boston Children’s Hospital randomly assigned 224 overweight or obese teenagers to receive home deliveries of bottled water and diet drinks for one year. The children also were regularly encouraged to avoid sugary drinks. Those who received the shipments gained only 3.5 pounds on average during that year, while a comparison group of similar teenagers gained 7.7 pounds. The differences between the groups evaporated after the deliveries stopped. In the second trial, researchers at VU University Amsterdam randomly assigned 641 normal-weight schoolchildren ages 4 to 11 to drink eight ounces of a 104-calorie sugar-sweetened or noncaloric sugar-free fruit-flavored drink every day from identical cans. Over 18 months, children in the sugar-free group gained 13.9 pounds on average, while those drinking the sugar-added version gained 16.2 pounds. © 2012 The New York Times Company

Keyword: Obesity; Development of the Brain
Link ID: 17286 - Posted: 09.22.2012

By Marla Cone and Environmental Health News Children exposed to higher levels of mercury or lead are three to five times more likely to be identified by teachers as having problems associated with Attention Deficit Hyperactivity Disorder, according to a scientific study published today. The study – of Inuit children in Arctic Quebec – is the first to find a high rate of attention-deficit symptoms in children highly exposed to mercury in the womb. In addition, the Inuit children more often had hyperactivity symptoms if they were exposed to the same low levels of lead commonly found in young U.S. children. In the United States, one of every 10 children has been diagnosed with ADHD, according to the U.S. Centers for Disease Control and Prevention. It is one of the most common brain disorders of childhood. Researchers from Laval University in Quebec surveyed teachers of 279 children in Nunavik between the ages of 8 and 14, using standardized questionnaires developed by psychiatrists for diagnosing ADHD. Developmental psychologist Gina Muckle, the study’s senior author, said the findings are important because they show for the first time that mercury’s effects on children are not just subtle, but are actually noticeable to teachers. The effects from exposure in the womb “may be clinically significant and may interfere with learning and performance in the classroom,” says the study, published online in the journal Environmental Health Perspectives. . © 2012 Scientific American

Keyword: ADHD; Neurotoxins
Link ID: 17285 - Posted: 09.22.2012

By Nathan Seppa People with multiple sclerosis might soon have a new option for controlling their disease with pills instead of shots. Two studies in the Sept. 20 New England Journal of Medicine demonstrate that a variation on a drug used against psoriasis for years in Germany holds off MS relapses and has minimal side effects. “These data look good. Both studies show a reduction in relapses with really pretty robust effects,” says Clyde Markowitz, a neurologist at the University of Pennsylvania who wasn’t involved with the trials. The drug, called BG-12, has been submitted to the U.S. Food and Drug Administration for approval by the biotech company Biogen Idec. Markowitz expects it to get approved. “It would be a clear benefit to the MS population to have another option,” he says. If approved, BG-12 would be the third oral drug available to treat MS. The disease results when the immune system attacks the fatty myelin sheaths coating nerves in the central nervous system, leading to impaired muscle control, balance, vision and speech. BG-12, or dimethyl fumarate, has anti-inflammatory, cell-protective and antioxidant effects, which earlier work suggested could suppress the aberrant immune reactions in MS patients. Scientists in both studies recruited MS patients and randomly assigned some in each group to BG-12 or placebo tablets. In one of the studies, an additional group was randomly assigned to get an injectable MS drug called glatiramer acetate (Copaxone). In other respects the studies were nearly identical, each enrolling more than 1,000 MS patients, ages 18 to 55, in 28 countries apiece, for two years of treatment. Both trials included a mix of North American and European researchers. © Society for Science & the Public 2000 - 2012

Keyword: Multiple Sclerosis
Link ID: 17284 - Posted: 09.22.2012

by Douglas Heaven Ever wish you could make better choices? That could one day be possible thanks to an electronic brain implant that can enhance short-term memory and decision-making in primates. The implant can also restore these functions in an animal model of Alzheimer's disease and other types of brain damage, paving the way for the development of new treatments for people with these conditions. Sam Deadwyler at Wake Forest University School of Medicine in Winston-Salem, North Carolina, and colleagues have previously shown that a neural implant can restore some motor and sensory functions in rats. Now they have used a similar implant to stimulate higher-level thinking in monkeys. During normal brain function, neurons "fire" when they receive an input from another neuron via the connection between them, called a synapse. The spatial and temporal pattern of this activity  – where and when the neurons fire   – can be detected and recorded. To find out if it is possible to hijack and then retune these patterns of activity, Deadwyler's team first trained five rhesus macaques to perform a task that tests their attention, short-term memory and decision-making skills. First, the monkeys were shown a random image from a pool of 5000. The image was then blanked out for an interval of 1 to 90 seconds, before reappearing in a different position, alongside up to seven other images. If the monkey selected the original image once it reappeared it was rewarded with juice. © Copyright Reed Business Information Ltd.

Keyword: Attention; Learning & Memory
Link ID: 17283 - Posted: 09.22.2012

Remember the game "telephone"? Someone starts by saying a sentence to the person next to them. That person then turns to someone else and repeats what they heard. Somehow, by the time the sentence gets to the last person in line, it's all mixed up and barely resembles the original. Apparently our memories operate in the same way. A study published recently in the Journal of Neuroscience looks at how we retrieve memories. It's a well-known phenomenon that retrieval is good for memory - the more you remember something, the longer you'll remember it for. The catch, researchers have discovered, is that each time you retrieve a memory you forget or add small things to it, and the next time you recall the information, you'll remember what you remembered. "Our memories aren’t like a photograph," says lead study author Donna Bridge. "We mix up details, we forget things. We’re likely to remember this incorrect information just as much as we are the correct (memory)." In other words, the more you recall an event, the more distorted your memory of that event may be. Bridge, a postdoctoral fellow at Northwestern University's Feinberg School of Medicine, asked 12 participants to take a memory test on three subsequent days. The first day, study participants repeatedly placed 180 objects in an assigned location - different for each one - on a computer screen grid. The second day they were asked to place those objects in the same positions. Twenty-four hours later, they did it again. © 2012 Cable News Network

Keyword: Learning & Memory
Link ID: 17282 - Posted: 09.22.2012

By Mary Bates It's an oft-repeated idea that blind people can compensate for their lack of sight with enhanced hearing or other abilities. The musical talents of Stevie Wonder and Ray Charles, both blinded at an early age, are cited as examples of blindness conferring an advantage in other areas. Then there's the superhero Daredevil, who is blind but uses his heightened remaining senses to fight crime. It is commonly assumed that the improvement in the remaining senses is a result of learned behavior; in the absence of vision, blind people pay attention to auditory cues and learn how to use them more efficiently. But there is mounting evidence that people missing one sense don't just learn to use the others better. The brain adapts to the loss by giving itself a makeover. If one sense is lost, the areas of the brain normally devoted to handling that sensory information do not go unused — they get rewired and put to work processing other senses. A new study provides evidence of this rewiring in the brains of deaf people. The study, published in The Journal of Neuroscience, shows people who are born deaf use areas of the brain typically devoted to processing sound to instead process touch and vision. Perhaps more interestingly, the researchers found this neural reorganization affects how deaf individuals perceive sensory stimuli, making them susceptible to a perceptual illusion that hearing people do not experience. These new findings are part of the growing research on neuroplasticity, the ability of our brains to change with experience. A large body of evidence shows when the brain is deprived of input in one sensory modality, it is capable of reorganizing itself to support and augment other senses, a phenomenon known as cross-modal neuroplasticity. © 2012 Scientific American

Keyword: Vision; Hearing
Link ID: 17281 - Posted: 09.19.2012

Children and teens with higher levels of BPA, a chemical used in canned foods, are more likely to be overweight and obese but whether the chemical caused the weight gain can’t be answered. The issue of obesity is addressed in Tuesday's online edition of the Journal of the American Medical Association. In one U.S. study, researchers wanted to test the idea that hormone-like chemicals like bisphenol A, also called BPA, could be contributing to childhood obesity by disrupting kids' metabolism. BPA is used to make hard plastics for food and beverage containers. It also found in the lining of many metal cans. Dr. Leonardo Trasande of the New York University School of Medicine and his co-authors looked at BPA concentrations in the urine of 2,838 Americans aged six to 19 as well as body mass index scores. "Urinary BPA concentrations was significantly associated with obesity in this cross-sectional study of children and adolescents," the study's authors concluded. The researchers weren't able to tell which came first, the obesity or BPA concentrations. © CBC 2012

Keyword: Obesity; Neurotoxins
Link ID: 17280 - Posted: 09.19.2012

Some people who are severely obese and have gastric bypass surgery may be able to keep weight off for six years, giving them reduced risks of cardiovascular problems and diabetes, a U.S. study finds. The study focused on 1,156 adults with a body mass index of 35 or higher — which is considered severely obese — and who had the bypass surgery. They were compared with 739 other severely obese people in two groups who did not get the surgery. "At six years, 96 per cent of surgical patients had maintained more than 10 per cent weight loss from baseline and 76 per cent had maintained more than 20 per cent weight loss," Ted Adams of the University of Utah School of Medicine and his co-authors wrote in Tuesday’s issue of the Journal of the American Medical Association. All cardiovascular risk factors improved or stayed the same among those who received a type of gastric bypass surgery called Roux-en-Y compared with those who did not, Adams said. Other differences at the end of the study included: Mortality rate three per cent for surgery patients, three per cent for obese patients who were evaluated and one per cent among the control group of obese adults. Diabetes remission 62 per cent for surgery, eight per cent in control group 1 and six per cent in control group 2. © CBC 2012

Keyword: Obesity
Link ID: 17279 - Posted: 09.19.2012

By GRETCHEN REYNOLDS Most people who start working out in hopes of shedding pounds wind up disappointed, a lamentable circumstance familiar to both exercisers and scientists. Multiple studies, many of them covered in this column, have found that without major changes to diet, exercise typically results in only modest weight loss at best (although it generally makes people much healthier). Quite a few exercisers lose no weight. Some gain. But there is encouraging news about physical activity and weight loss in a new study by researchers at the University of Copenhagen. It found that exercise does seem to contribute to waist-tightening, provided that the amount of exercise is neither too little nor, more strikingly, too much. To reach that conclusion, the Danish scientists rounded up a group of pudgy and sedentary young men, a segment of the population increasingly common in Denmark, as elsewhere in the world. The volunteers, most in their 20s or early 30s, visited the scientists’ lab to undergo baseline measurements of their aerobic fitness, body fat, metabolic rates and general health. None had diabetes, high blood pressure or heart disease and, while heavy, they were not obese. The men were then randomly assigned to exercise or not. The non-exercisers, who served as controls, returned to their former routines, with no change to their diets or sedentary ways. A second group began 13 weeks of almost daily moderate workouts, consisting of jogging, cycling or otherwise sweating for about 30 minutes, or until each man had burned 300 calories (based on his individual metabolic rate). Copyright 2012 The New York Times Company

Keyword: Obesity
Link ID: 17278 - Posted: 09.19.2012

By James Gallagher Health and science reporter, BBC News Up to a million people in the UK have "completely preventable" severe headaches caused by taking too many painkillers, doctors have said. They said some were trapped in a "vicious cycle" of taking pain relief, which then caused even more headaches. The warning came as part of the National Institute for Health and Clinical Excellence's (NICE) first guidelines for treating headaches. It is also recommending acupuncture in some circumstances. "Medication overuse headaches" feel the same as other common headaches or migraines. There is no definitive UK data on the incidence of the condition, but studies in other countries suggest 1-2% of people are affected, while the World Health Organization says figures closer to 5% have been reported. While painkillers would be many people's instant response, they could be making sufferers feel even worse. Prof Martin Underwood, from Warwick Medical School, who led the NICE panel, said: "This can end up getting into a vicious cycle where your headache gets worse, so you take more painkillers, so your headache gets worse and this just becomes worse and worse and worse. BBC © 2012

Keyword: Pain & Touch
Link ID: 17277 - Posted: 09.19.2012

In May, my six-year-old daughter, Julia, smashed into our front door handle and got a deep, bloody gash in her forehead. We rushed her, head wrapped like a tiny mummy, to the medical center at MIT, where we generally go for pediatric care. Julia wept while the nurse cleaned and examined her lacerated skin. After a short exam, she sent us to the emergency department at Children’s Hospital Boston for stitches. “How bad is that, generally?” I asked, having never experienced suturing either for myself or my cautious, risk-averse, older daughter. “It can be traumatic,” the nurse said. Julia cried, “I don’t want stitches.” It’s a large needle, but Julia is too busy coloring to notice. So I braced myself for the worst: an endless wait and nerve-wracking bustle; screaming, germ-laden children and brusque, end-of-shift staff. But more than anything, I dreaded the inevitable pain in store for my small child with the deep cut. (I know, kids get banged up on the path to adulthood and some pain is unavoidable. Still, when bloody heads are involved, I tend to overreact.) Indeed, I was in full Mama Bear mode when into our exam room strode Dr. Baruch Krauss, the attending physician that evening. Copyright Trustees of Boston University

Keyword: Pain & Touch; Attention
Link ID: 17276 - Posted: 09.19.2012

By Laura Sanders A dose of Ritalin makes healthy women more reckless in a gambling game. After taking the stimulant, participants in an experiment shifted their betting strategy and kept playing even when faced with stakes too high for most folks. Though solid numbers are scarce, evidence suggests that many healthy people turn to Ritalin (also known as methylphenidate) and other stimulants to boost mental capacity. Some college students, for instance, rely on these “smart pills” to focus attention in cram sessions before tests. The new results, published in the Sept. 19 Journal of Neuroscience, suggest that the drugs might have unanticipated consequences for these people, says study coauthor Daniel Campbell-Meiklejohn of New York University. Scientists have known that the very same drug has an opposite effect in people with attention deficit hyperactivity disorder and a kind of dementia, normalizing these people’s risky behavior. Scientists can’t yet explain Ritalin’s divergent effects, but they suspect that variations in how the brain handles the chemical messenger dopamine may be involved. Researchers enlisted 40 healthy women to take either Ritalin or a placebo, and later play a gambling game. The game was rigged so that the players would quickly rack up a loss and then have to choose whether to double-down in the hopes of recovering their money. “That’s the sad part of the game,” says Campbell-Meiklejohn, who conducted the study while at Aarhus University in Denmark. “You really can’t win.” © Society for Science & the Public 2000 - 2012

Keyword: Drug Abuse; ADHD
Link ID: 17275 - Posted: 09.19.2012

2012 by Graham Lawton My usual pick-me-up on a Monday morning is a cup of coffee. Today it's going to be something very different. I've been up since 6 am. I've had a breath test for alcohol, a urine test for drugs and a psychological test for mental health. Then I'm handed a red pill and a glass of water. I swallow it… and I'm told to relax. Which is easier said than done when you don't know if you've just taken vitamin C or 83 milligrams of pure MDMA. Half an hour later I'm inside an fMRI brain scanner, my head clamped in place and a visor over my face. It's noisy and claustrophobic but I'm reassured by the panic button in my hand and a voice from the control room. And then I start to feel it. A tingle of energy, like pins and needles, starts in the pit of my stomach and rises slowly, not unpleasant but not exactly pleasurable either. It builds in intensity, then breaks into a wave of bliss. The placebo effect can be powerful but when it happens again, I'm in no doubt. I'm coming up. I'm taking part in a groundbreaking study on MDMA, the drug commonly known as ecstasy. The research is run by David Nutt of Imperial College London, a former government adviser and one of the few UK researchers licensed to study class-A drugsMovie Camera. His main aim is to discover what MDMA does to the human brain, something that, remarkably, has never been done before. A second goal is to study MDMA as a therapy for post-traumatic stress disorder. © Copyright Reed Business Information Ltd

Keyword: Drug Abuse; Brain imaging
Link ID: 17274 - Posted: 09.19.2012

by Virginia Morell Imagine hearing a distant roll of thunder and wondering what caused it. Even asking that question is a sign that you, like all humans, can perform a type of sophisticated thinking known as "causal reasoning"—inferring that mechanisms you can't see may be responsible for something. But humans aren't alone in this ability: New Caledonian crows can also reason about hidden mechanisms, or "causal agents," a team of scientists report today in the Proceedings of the National Academy of Sciences. It's the first time that this cognitive ability has been experimentally demonstrated in a species other than humans, and the method may help scientists understand how this type of reasoning evolved, the researchers say. Causal reasoning is "one of the most powerful human abilities," says Alison Gopnik, a psychologist at the University of California, Berkeley, who was not involved in the study. "It's at the root of our understanding of the world and one another." Indeed, it is the key mental ability for many things humans do, including inventing, making, and using tools. We develop this ability early in life: A 2007 study in Developmental Psychology reported that human infants as young as 7 months old understand that when a beanbag is tossed from behind a screen, something or someone must have thrown it. The infants infer that a "causal agent" must be involved in the motion of the flying beanbag. But why should this ability be limited to humans? "It seems like it would make good sense for crows and many other animals to be able to distinguish between the wind rustling tree limbs and an unseen animal crashing through the canopy," says Alex Taylor, an evolutionary psychologist at the University of Auckland in New Zealand and the lead author of the new study. Because New Caledonian crows are also inventive and skillful tool-users, Taylor and his colleagues thought the birds might have causal reasoning skills similar to those of humans. © 2010 American Association for the Advancement of Science

Keyword: Intelligence; Evolution
Link ID: 17273 - Posted: 09.18.2012

By DAVID TULLER Chronic fatigue syndrome is not caused by a mouse retrovirus, according to a study initiated by the National Institutes of Health to settle what had become a contentious scientific question. The long-awaited results, posted online Tuesday in the journal mBio, found no link between the illness, also called myalgic encephalomyelitis, and mouse leukemia retroviruses, including one called XMRV. Two earlier studies had identified higher levels of the viruses in patients with chronic fatigue syndrome. Later research did not confirm the finding, and scientists blamed laboratory contamination for the earlier results. The N.I.H. asked Dr. Ian Lipkin, a virologist at Columbia, to investigate. Dr. Lipkin recruited in the effort scientists who initially reported the link to mouse retroviruses, and they serve as authors on the mBio paper. In the study, none of the researchers reported finding mouse leukemia viruses in any of 293 blood samples, half from people with chronic fatigue syndrome and half from those without it. An estimated one million people in the United States have the condition; many are severely disabled and homebound. Dr. Lipkin said that he viewed chronic fatigue syndrome as a major illness and intended to use blood samples he had obtained to investigate the causes. Copyright 2012 The New York Times Company

Keyword: Stress; Depression
Link ID: 17272 - Posted: 09.18.2012