A single change in a particular brain hormone can increase a person's risk of obesity, two new studies in the February 8, 2006, Cell Metabolism reveal. The researchers found that obese children are more likely to carry a rare variant of so-called ß-melanocyte-stimulating hormone (ß-MSH) than children of normal weight. The findings implicate the hormone in the maintenance of normal body weight and suggest that drugs that mimic the chemical might offer a new avenue for obesity treatment, report the studies' lead authors Stephen O'Rahilly, of the Cambridge Institute for Medical Research in the United Kingdom, and Heiko Krude, of Charité Universitätsmedizin Berlin in Germany. The hormone's important role in maintaining body weight had been overlooked primarily because mice and rats, the subjects of much obesity research, do not produce the chemical, they added. Earlier studies had focused their attention almost entirely on the related chemical α-MSH, a hormone derived from the same precursor protein that is known to suppress appetite in humans and rodents. "The assumption had been that α-MSH was most important at keeping energy balanced in people," O'Rahilly said. "The new studies point the finger at the neglected sibling, ß-MSH."

Keyword: Obesity
Link ID: 8504 - Posted: 02.09.2006

LIFTING a finger is easy. What is far more difficult is understanding how our brains sense that it has moved. For over a century scientists have struggled to understand which parts of the nervous system allow the body to sense its own position in space. Now Simon Gandevia of the Prince of Wales Medical Research Institute in Sydney, Australia, and colleagues have devised a technique which clearly demonstrates that the brain only has to send a command to a limb to create the sensation of movement. Their discovery goes some way to resolving the enigma of whether motor commands or receptors in the skin, joints and muscles are more important for creating a feeling of movement. Gandevia's team studied eight volunteers, by either anaesthetising their forearm and hand, or restricting the flow of blood to the limb. Both techniques deadened sensation to the extent that the volunteers felt they had a "phantom" hand with fingers clenched, though in fact their fingers were fully extended. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 8503 - Posted: 06.24.2010

By Denise Winterman Nearly half of the British children with an eating disorder feel unable to talk about their problem, says a report from the Eating Disorders Association (EDA). It is estimated that more than a million people in the UK have anorexia or bulimia and many of them are young. The report says eating disorders are still misunderstood and mistaken, sometimes seen as trivial and self-inflicted when they are actually serious and life-threatening mental illnesses. Early treatment is vital if people are to avoid long-term consequences to their physical and mental health, but many youngsters keep their condition secret - including one such teenager who has kept a diary of her relationship with food. Sarah - not her real name - lives in Manchester with her mother and sister. The 18-year-old student has had an eating disorder for four years. Here she details how food dominated her last week. MONDAY Monday usually starts with a list of resolutions about what food I am not going to allow myself to eat in the next week. I want to control what I eat and get a feeling of excitement at the strict targets I set myself. When I am at college it is easy to do. The hard part starts when I get home from college. My family know I have a problem and insist on family meal times. (C)BBC

Keyword: Anorexia & Bulimia
Link ID: 8502 - Posted: 02.07.2006

By NICHOLAS BAKALAR The results of two new studies underscore the quandary that faces women taking antidepressants who are pregnant or plan to be. In one, researchers report that pregnancy, contrary to widespread belief, provides no protection against emotional or psychiatric problems, suggesting that stopping antidepressants may be dangerous for both mother and child. The other study confirms previous research showing that 30 percent of pregnant women who take antidepressants have babies who exhibit symptoms of drug withdrawal. The first study, published last week in The Journal of the American Medical Association, found that women with major depression who stopped their medication relapsed more than two and a half times as often as women who continued to take antidepressants. Dr. Lee S. Cohen, the lead author on the study and a psychiatrist at Massachusetts General Hospital, emphasized that this was an observational study of women who were already taking the drugs, and not a randomized trial. Two of the authors have consulted for pharmaceutical companies that make antidepressants or have accepted research money from them. Copyright 2006The New York Times Company

Keyword: Depression
Link ID: 8501 - Posted: 02.07.2006

By DONALD G. McNEIL Jr. For wildly hallucinatory visions in an atmosphere of sheer terror, nothing has quite brought back the one LSD trip I took in college like getting cataract surgery. Back then, I tried to go to Disneyland — a stupendously bad idea. This time I was in an equally controlling environment, my head taped to an operating table with a black spiderlike thing holding my eye open as a pink glob in front of it pulsed to the music. But at least this time, the masked authority figures were friendly. There were two other major differences. It was all over in 10 minutes. And I was drug free. Modern cataract surgery is remarkable. I remember my grandmother having her cataracts fixed, and she was laid up for days, wearing a patch that would have made her look piratical, except it was flesh-colored. I left the New York Eye and Ear Infirmary wearing a clear plastic lid that made my eye look like a piece of takeout sushi. Unlike my grandmother, I could see. Moreover, I felt well enough to risk having oysters for lunch, something one wouldn't sensibly do after anesthesia. Copyright 2006The New York Times Company

Keyword: Vision
Link ID: 8500 - Posted: 06.24.2010

By JAMES GORMAN English literature is rife with references to the smelling of rats, as in the classic verse report on maternal care in Felis silvestris catus: "What! washed your mittens, you are good kittens. But I smell a rat close by." The scientific literature, on the other hand, is more concerned with how rats smell — that is to say, how they detect and process odors. And the answer, reported in the current issue of the journal Science, is — in stereo. Rats, as many of us inside and outside of neuroscience have suspected, use their sense of smell to find the source of odors, good and bad. They and other animals are much better at this task than humans. Witness the common behavior patterns of juvenile human males, who are so incompetent at pinpointing the location of unpleasant odors that they discuss the problem endlessly. Rats have no such problem, as Raghav Rajan, James P. Clement and Upinder S. Bhalla at the University of Agricultural Science in Bangalore, India, have recently demonstrated. They trained rats to associate an odor with water. Then the rats had to determine whether the odor was coming from the left or the right. This was done with a contraption that Mr. Wizard would have loved. Copyright 2006The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8499 - Posted: 06.24.2010

Two Dartmouth researchers are one step closer to defining exactly when human maturity sets in. In a study aimed at identifying how and when a person's brain reaches adulthood, the scientists have learned that, anatomically, significant changes in brain structure continue after age 18. The study, called "Anatomical Changes in the Emerging Adult Brain," appeared in the Nov. 29, 2005, on-line issue of the journal Human Brain Mapping. It will appear in a forthcoming issue of the journal's print edition. Abigail Baird, Assistant Professor of Psychological and Brain Sciences and co-author of the study, explains that their finding is fascinating because the study closely tracked a group of freshman students throughout their first year of college. She says that this research contributes to the growing body of literature devoted to the period of human development between adolescence and adulthood. "During the first year of college, especially at a residential college, students have many new experiences," says Baird. "They are faced with new cognitive, social, and emotional challenges. We thought it was important to document and learn from the changes taking place in their brains." The results indicate that significant changes took place in the brains of these individuals. The changes were localized to regions of the brain known to integrate emotion and cognition. Specifically, these are areas that take information from our current body state and apply it for use in navigating the world. Copyright © 2006 Trustees of Dartmouth College

Keyword: Development of the Brain; Learning & Memory
Link ID: 8498 - Posted: 06.24.2010

Berkeley -- University of California, Berkeley, researchers have discovered a new actor in the mammalian reproductive system, a hormone that fills a role long suspected, but until now undetected. The hormone, a small protein, or peptide, called gonadotropin-inhibitory hormone (GnIH), puts the brakes on reproduction by directly inhibiting the action of the central hormone of the reproductive system - gonadotropin releasing hormone (GnRH). GnRH stimulates the pituitary gland to activate the reproductive system, whereas GnIH appears to reduce the effects of GnRH stimulation. Researchers have long sought inhibitors of pituitary gonadotropins, but many had come to believe that such a direct inhibitor was unlikely in the complex cast of hormones and factors in the reproductive system. The inhibiting or braking hormone may complement the "gas pedal" role played by another recently discovered hormone, kisspeptin, that stimulates GnRH. The discovery in rats, mice and hamsters of this new system for regulating reproduction strongly suggests that the hormone plays a similar role in the reproductive systems of humans and other mammals. The human genome, in fact, contains a gene for GnIH.

Keyword: Hormones & Behavior
Link ID: 8497 - Posted: 02.07.2006

By Jennifer Viegas, Discovery News — Sexual orientation appears to influence how humans perceive the faces of other individuals, according to a new study that analyzed the brain activity of heterosexual and homosexual men and women while they viewed and rated photographs of faces. Scientists previously theorized that assessment of reproductive fitness was the only guiding force behind our gut reaction to faces of potential mates. That theory holds that good bone structure, well-balanced features and sexual dimorphism — manly men and feminine women — subconsciously tell us that a member of the opposite sex likely could produce healthy children. The authors of the new study now believe that other qualities, such as compatibility and companionship, may be just as important. "My personal thought: finding a mate is not only about potential reproduction," said Alumit Ishai, who coauthored the study with Felicitas Kranz. "A mate obviously has other important roles — friendship, intimacy, emotional stability, financial security, etc. My study suggests that these values may be coded by the preferential activity in the (brain's) reward circuitry." Copyright © 2006 Discovery Communications Inc.

Keyword: Sexual Behavior; Brain imaging
Link ID: 8496 - Posted: 06.24.2010

By Jane Elliott Doctors hope they will soon be able to assess exactly how much pain their patients are suffering. As many as one in four people suffer from chronic pain - people like Malcolm Pankhurst who was plagued for years by chronic back pain. Until now, doctors have had to rely on patients' descriptions of their pain. But now researchers at the Pain Clinical Research Hub, based at King's College Hospital (KCH) and the Institute of Psychiatry, London, are using the latest imaging techniques to measure the brain activity of people in pain to get an objective measurement of its intensity. They hope that knowing how much pain the patient is really suffering will teach them whether the treatments they are prescribing are doing enough to help. Malcolm says anything that can help others escape the years of suffering he endured can only be welcomed. He first noticed a problem with his back nearly 10 years ago. Years of sitting hunched over a desk in his job in the banking industry had taken its toll. One New Year, his back started to ache. Within hours he was in excruciating pain unable to sit, and he was rapidly referred for surgery. He suffered three prolapsed discs and severe pains in his leg and foot. The problem became so bad he had to have discs removed. But the pain continued and Malcolm, aged 53, decided to quit his high profile job and set up his own business selling specialised chairs to back pain sufferers like himself. (C)BBC

Keyword: Pain & Touch; Brain imaging
Link ID: 8495 - Posted: 02.06.2006

By Susan Levine Even among the incident reports crossing Craig Knoll's desk weekly now, this one stood out: A 43-year-old client of Knoll's mental health agency, a man who suffers from bipolar disorder, had come from his pharmacy frustrated to the point of meltdown. There were snags in his new Medicare drug plan. Of his four medicines, it would fill only two. "I'm not going to take any of them anymore," he yelled, according to the report by caseworkers. Before they could do anything, he grabbed the prescription bottles he'd just gotten, ran for the restroom and dumped both in the toilet. "He flushed everything he had on hand," recounted Knoll, executive director of Threshold Services in Silver Spring, whose staff spent day after day last month grappling with the many ramifications of the government's troubled program. Threshold came to the rescue of clients who couldn't get any medications or who, despite their pills, were in increasing distress because of all the confusion. It reimbursed several who'd mistakenly paid hundreds of dollars for pills that should have cost them a few dollars -- and replenished the supply of the client who had thrown his away. "I'm not saying it's the federal government's fault he flushed his meds," Knoll said. "I'm saying it's the federal government's fault he couldn't get his meds. It's not surprising that people with mental illness respond in ways that people with mental illness respond." © 2006 The Washington Post Company

Keyword: Schizophrenia; Depression
Link ID: 8494 - Posted: 06.24.2010

By ROBIN MARANTZ HENIG Liars always look to the left, several friends say; liars always cover their mouths, says a man sitting next to me on a plane. Beliefs about how lying looks are plentiful and often contradictory: depending on whom you choose to believe, liars can be detected because they fidget a lot, hold very still, cross their legs, cross their arms, look up, look down, make eye contact or fail to make eye contact. Freud thought anyone could spot deception by paying close enough attention, since the liar, he wrote, "chatters with his finger-tips; betrayal oozes out of him at every pore." Nietzsche wrote that "the mouth may lie, but the face it makes nonetheless tells the truth." This idea is still with us, the notion that liars are easy to spot. Just last month, Charles Bond, a psychologist at Texas Christian University, reported that among 2,520 adults surveyed in 63 countries, more than 70 percent believe that liars tend to avert their gazes. The majority also believe that liars squirm, stutter, touch or scratch themselves or tell longer stories than usual. The liar stereotype exists in just about every culture, Bond wrote, and its persistence "would be less puzzling if we had more reason to imagine that it was true." What is true, instead, is that there are as many ways to lie as there are liars; there's no such thing as a dead giveaway. Most people think they're good at spotting liars, but studies show otherwise. A very small minority of people, probably fewer than 5 percent, seem to have some innate ability to sniff out deception with accuracy. But in general, even professional lie-catchers, like judges and customs officials, perform, when tested, at a level not much better than chance. In other words, even the experts would have been right almost as often if they had just flipped a coin. Copyright 2006 The New York Times Company

Keyword: Stress
Link ID: 8493 - Posted: 02.06.2006

Tastebuds alone do not determine what something tastes like. Researchers have demonstrated that expectation, too, plays a role. Previous research in primates had suggested that expectation had little effect on how taste registers in the brain. Neuroscientist Jack Nitschke and his colleagues at the University of Wisconsin lined up 30 college-age volunteers to see whether the same holds true for humans. The neuroscience team prepared five drinks containing water mixed with varying amounts of quinine or sugar and paired them with five signs: water with a strong concentration of quinine linked to a minus sign; water with a milder concentration got a crossed-out minus sign; simple distilled water received a zero; and water with either a mild or strong concentration of sugar got the plus sign equivalents of their negative counterparts. After three trial runs, the students had learned the associations. The researchers then loaded the subjects into an fMRI machine for the next stage of the experiment. This time, however, they mixed the signs and drinks. For example, the crossed-out minus sign--initially paired with the milder quinine mixture--sometimes preceded the bitterest drink during the eight tastings in the machine. © 1996-2006 Scientific American, Inc.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8492 - Posted: 06.24.2010

By BENEDICT CAREY At this rate, it seems that neuroscientists will soon pinpoint the regions in the brain where mediocre poetry is generated, where high school grudges are lodged, where sarcasm blooms like a red rose. In the last month alone, researchers working with brain imaging machines have captured the neural trace of schadenfreude and the emotional flare of partisan thinking and whatever happens between the ears of a happily married woman when her husband takes her hand. As the magnetic resonance imaging machines produce pictures with higher resolution — and that is happening fast — hundreds of such studies are being published in scientific journals each month. Meanwhile, a parallel stream of popularizing books, magazines and newspapers, including this one, are publicizing an ever-enlarging array of the now familiar red, gray and blue graphics of imaged brains, and some of them are making extravagant claims for their significance. Already, lawyers have used M.R.I. brain images to help reduce criminal sentences, arguing that their clients' actions can partly be explained by the way their brains function, or malfunction. Some researchers say their imaging methods can help detect lies. Copyright 2006 The New York Times Company

Keyword: Brain imaging
Link ID: 8491 - Posted: 06.24.2010

The ability of a cell to sense its position within a tissue may help explain why some people become obese, scientists believe. An international team is focusing on an inherited syndrome that causes obesity in children, among other symptoms. They suspect that part of the problem could be faults in cells in the part of the brain that controls appetite. The cells may lack normal location sense and migrate to the wrong place, they told Nature Genetics. The condition the researchers are studying is called Bardet-Biedl syndrome, or BBS, but they believe their work could shed light on obesity in general. Children born with BBS are obese and go blind and develop kidney failure. Past work has uncovered at least eight faulty genes that can cause the disorder, but it is still not clear exactly how. Professor Peter Beales from University College London Institute of Child Health, working with colleagues from Canada, France and the US, has discovered a possible cell function that may go amiss in BBS. By looking at a mouse model of BBS, they found there were problems with tiny hair-like projections on cells, known as cilia. These hairs are important for telling the cell where in the body it is positioned in relation to other cells. Without this function the cell can get lost. They believe such malfunction could play a role in the symptoms of BBS and its related obesity. (C)BBC

Keyword: Obesity
Link ID: 8490 - Posted: 02.04.2006

Helen Pearson Expecting the worst may not make you feel any better when faced with a disappointment, say psychology researchers who have tested the age-old advice. Most people believe that mentally preparing for the worst outcome in an examination or race will soften the disappointment if we flunk or flop - and heighten the joy if we succeed. But the idea has rarely been put on scientific trial. Margaret Marshall of Seattle Pacific University and Jonathon Brown of the University of Washington, Seattle, did just that. They first asked more than 80 college students to fill in questionnaires that measured their general emotional outlook on life - whether bright or gloomy. The students then practised a set of moderately difficult word-association puzzles on a computer. Based on this, they rated how well they expected to perform on a second set of such problems. The team then gave half the students problems that were slightly easier than the first set, while half were given more difficult puzzles. This ensured that the students' performances would either exceed, or fall short of, their expectations. Afterwards, the subjects filled in a questionnaire to measure their emotional reaction, such as how disappointed or ashamed they felt. Students who expected to do badly, the researchers found, actually felt worse when they messed up than those who predicted they would do well but similarly botched their test. © 2004 Nature Publishing Group

Keyword: Emotions
Link ID: 8489 - Posted: 06.24.2010

Women who feel that they become more forgetful as menopause approaches shouldn't just "fuhgetabout it": There may be something to their own widespread reports that they're more likely to forget things as menopause approaches, say scientists who reported results from a small study today at the annual meeting of the International Neuropsychological Society in Boston. The team from the University of Rochester Medical Center found that the issue is not really impaired memory. Instead, the team found a link between complaints of forgetfulness and the way middle-aged, stressed women learn or "encode" new information. "This is not what most people think of traditionally when they think of memory loss," said co-author Mark Mapstone, Ph.D., assistant professor of Neurology. "It feels like a memory problem, but the cause is different. It feels like you can't remember, but that's because you never really learned the information in the first place." The findings come from Mapstone and Miriam Weber, Ph.D., memory experts at the University's Memory Disorders Clinic who are seeing more and more middle-aged women who say they are having problems with forgetfulness. "We see a lot of women who are afraid they are losing their minds," said Weber, a senior instructor of Neurology, who presented the results. "A lot of women complain that their thinking or their memory isn't what it used to be. Their big fear is that it's early Alzheimer's disease."

Keyword: Hormones & Behavior; Learning & Memory
Link ID: 8488 - Posted: 02.04.2006

By Laurance Doyle The Native American tribe known as the Tlinket of southeast Alaska have many stories about how raven stole the Sun, how bear and ant argued about the constellations, and how the wolf and moon are related. But as far as I know, they don’t have any stories about the humpback whale. If they did, they might have told how the humpback gave voices to all the other animals, for this creature has all the voices of the animal kingdom. We have recorded humpbacks making sounds like the trumpeting of elephants, roars like lions, whistles like dolphins, clicks like the sperm whale, mooing like cows, chattering like monkeys, and several very human-like vocalizations—some even sounding like an unusual language, with exclamations like "whoops!" Although we are just beginning to document and classify all the diverse sounds of the humpback whales, we already expect its repertoire to exceed that of any other animal we have studied to date. The humpbacks of southeast Alaska are known to migrate thousands of miles to Hawaii to mate, where they sing long and complex songs. Several variations of these songs are started at the beginning of the season, then eventually all humpbacks are singing the same song for that year. They head to Alaska in the summer to feed, and here they have a different kind of vocalization based more on feeding needs. However a colleague, Chris Gabriele of Glacier Bay National Park System, has also found that humpback whales still sing even in this feeding season. © 1999-2006 Imaginova Corp.

Keyword: Language; Evolution
Link ID: 8487 - Posted: 06.24.2010

(Philadelphia, PA) – In a mouse model, University of Pennsylvania School of Medicine researchers discovered that olfactory sensory neurons expressing the same receptor responded to a specific odor with an array of speeds and sensitivities, a phenomenon previously not detected in the mammalian sense of smell. The group published their findings this week in the online edition of the Proceedings of the National Academy of Sciences. "We assumed that the sensory neurons that express the same receptor would respond to a specific odor in the same way," says senior author Minghong Ma, PhD, Assistant Professor of Neuroscience at Penn. "But in real biology, these olfactory neurons keep regenerating, and even though they all express the same receptor, they're probably at different states of maturation, displaying different qualities. By knowing that olfactory neurons can respond differently, we're adding another layer to understanding how the olfactory system receives outside information." Ma's group measured 53 different olfactory neurons that express the MOR23 odor receptor. As a group, the neurons reacted differently from one another in their response to lyral, an artificial odor used in fragrances and flavoring. After subjecting all cells to a short pulse (200-300 milliseconds) of lyral, the researchers measured the cells' sensitivity to the odor. Some cells responded to very low concentrations of lyral; others, to higher concentrations. Regarding the cells' reaction time, some neurons finished firing within 500 milliseconds, but for others, the response time was up to five seconds.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8486 - Posted: 06.24.2010

By Greg Miller Not all placebos are created equal, according to a new study. In a rare trial pitting two fake treatments against each other, researchers have found that a sham acupuncture technique provided more pain relief than a dummy pill. The two nontreatments also caused different "side effects." Placebo effects have been reported with pills, injections, and even surgery. Previous research hinted that some treatments might elicit stronger placebo effects than others, but the idea hadn't been rigorously tested, says Ted Kaptchuk, the researcher at Harvard Medical School in Boston who led the current study. Kaptchuk and colleagues recruited 270 people with repetitive strain injuries (such as the aching arm that results from pushing a computer mouse around a desktop day after day). Half the volunteers took a cornstarch pill once a day; the rest received a fake acupuncture treatment twice a week. Both groups were told they would receive either a placebo or real treatment during the trial and that they could receive real treatment afterwards free of charge. The needles used in the procedure looked identical to real acupuncture needles, but the point retracted into a hollow shaft instead of penetrating the skin. The vast majority of people can't feel the difference between the sham procedure and the real deal, Kaptchuk says. © 2006 American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 8485 - Posted: 06.24.2010