Lucy Heady Researchers have worked out how a mammal's tongue detects sour tastes: it's all down to a single, specialized receptor, they say. Taste in mammals is classified into sweet, salty, bitter, sour and umami (the taste of monosodium glutamate, commonly found in Chinese takeaways). Until now, only the sweet, bitter and umami taste receptors had been identified, and researchers were unsure whether the other two tastes had specialized receptors for them at all. The three tastes with known receptors are triggered by large molecules, such as sucrose, that latch on to and are recognized by specialized cells on the tongue. But salty and sour are different in that they are the tastes of very simple ions: hydrogen ions (H+) for acidity and, mainly, sodium ions (Na+) for salt. Some researchers have speculated that many cells in the tongue might be able to pick up these signals, relaying the information in a complex pattern of nerve signals to the brain. "This kind of model is very messy," says Charles Zuker of the Howard Hughes Medical Institute in San Diego. So Zuker's team — the same lab that pinned down the previous three taste receptors — set out to hunt for a sour taste receptor. Angela Huang, a graduate student in Zuker's lab, first trawled through the mouse genome to pick out any proteins that exist in cell membranes: proteins that can pick up signals from the outside world and transmit them to nerves. That left about 10,000 candidates. ©2006 Nature Publishing Group

Keyword: Chemical Senses (Smell & Taste)
Link ID: 9266 - Posted: 06.24.2010

Tracy Staedter, Discovery News — A wearable computer system that emits audio cues could help guide the visually impaired. The System for Wearable Audio Navigation, or SWAN, combines global positioning system (GPS) technology with cameras and image processing software to locate a person's whereabouts and "see" details such as windows, doors and corners. "In the future, we could even use the cameras to recognize people or objects," said Frank Dellaert, who developed the system at the Georgia Institute of Technology with Bruce Walker. The technology could do everything from lead a blind person through a new neighborhood to help firefighters or soldiers plot a course in darkness. Since about 2001, visually impaired people have had access to commercial GPS-based navigation systems meant to help them get around. The technology is available on handheld electronic devices such as laptops or PDAs and is similar to that used in cars. A GPS sensor pinpoints the person on a grid, while the computer's database — which contains street names as well as businesses — matches the information to the location. Copyright © 2006 Discovery Communications Inc.

Keyword: Vision; Robotics
Link ID: 9265 - Posted: 06.24.2010

By RICHARD A. FRIEDMAN, M.D. Most people reach their sexual peak at a time when, to put it charitably, they don’t always make the best use of their libido. My patient Dan, a 53-year-old in perfect physical health, refers to this as biology’s cruel joke, meaning now that he really knows what he wants in life, he would love to recapture some of his youthful sexual vigor and put it to good use. After years of psychotherapy, he had never felt more satisfied: he was at his pinnacle professionally and had a wife and three children whom he clearly adored. One day in therapy he asked me, “Do you think I could get some Viagra?” I don’t consider myself the least bit puritanical, but I’m usually in the business of making the sick better, not making the normal better than well. When I asked him why, he admitted there was no problem; he just wanted to jazz things up. “Is your wife complaining about sex?” I asked. “Oh, no, she seems very happy with the status quo. We have sex about once a week and maybe more on vacation,” he said. “Besides, what’s the harm? So many of my friends use Viagra for a security blanket or a boost.” Copyright 2006 The New York Times Company

Keyword: Sexual Behavior
Link ID: 9264 - Posted: 06.24.2010

By JAMES GORMAN As humans age, so I’m told, they tend not to sleep as well as they once did. There are all sorts of reasons — aches and pains, worries about work, and lifelong accumulations of sins that pretty much rule out the sweet sleep of innocence. Not as a cause of insomnia. What about the problems fruit flies have sleeping? Yes, Drosophila melanogaster also suffer sleep disruption when they get older. And a report on the troubled sleep of drosophila is being published in The Proceedings of the National Academy of Sciences. This is the kind of science that makes you wonder. For instance, are the female flies suffering from hot flashes? Are the male flies getting up to go to the bathroom three or four times a night? Of course not. Fruit flies don’t have bathrooms. Or you may wonder what troubles are keeping the flies up. They don’t have to worry about family values, illegal immigration or debt. They don’t have families or money. And given the ubiquity of fruit and of scientific research, I’m guessing drosophila, bless their little genomes, must benefit from something close to full employment. Copyright 2006 The New York Times Company

Keyword: Evolution; Sleep
Link ID: 9263 - Posted: 06.24.2010

WHAT'S the difference between the male and female brain? Ah, if only we had a dollar for every one-liner that has been spawned by that little poser. An entire industry of books, films, key fobs and stand-up comedians owes its existence to the rich seam of humour that can be mined from the disparity between the sexes. Why is psychoanalysis quicker for men than for women? Because when it's time to go back to childhood, he's already there. Why does a man have a hole in his penis? So the air can get to his brain. What's the main difference between women and men? Women can use sex to get what they want; men can't because sex is what they want. Ha, ha, ha. But when science asks the same question, we seem to lose our sense of humour. Experts who point to biological differences in the male and female brain as a way of explaining behaviour are seen by some as shattering taboos and reinforcing stereotypes. To some, to look for differences is to look for ways to discriminate against women. Louann Brizendine, an American neuropsychiatrist, knows that she will take some flak when her new book, The Female Brain, is published later this month. In Newsweek, she describes the book as a "kind of owner's manual for women" and in it discusses what she believes are the biological reasons that girls gravitate to dolls and boys gravitate to trucks, and which hormones drive teenage girls to become obsessed with shopping and sending mobile phone text messages. © The Australian

Keyword: Sexual Behavior
Link ID: 9262 - Posted: 06.24.2010

ST. PAUL, Minn. -- Children with autism have altered brain anatomy thought to be due to abnormal brain development, according to a study published in the August 22, 2006, issue of Neurology, the scientific journal of the American Academy of Neurology. The study compared 60 autistic children to 16 children with developmental delay and 10 children with typical development. All of the children were age two to four. Using magnetic resonance imaging scans (MRI), the researchers measured the transverse relaxation (T2) of cortical gray and white matter in the children's brains. T2 relaxation is a measure of how tightly bound, or mobile, water is in brain tissue and has been used to measure the temporal progression of brain maturation. The researchers found that the autistic children had differences in the gray matter of their brains compared to the children with typical development. "One of the more consistent brain findings associated with autism has been enlarged brain size," said study author Stephen Dager, MD, of the University of Washington School of Medicine in Seattle. "In contrast to current theories which suggest the enlarged brains are due to accelerated early growth tied to a more advanced stage of brain maturation, gray matter T2 relaxation findings were in the opposite direction. These results suggest that the mechanism or mechanisms responsible for larger brains in autism are different from more rapid growth."

Keyword: Autism; Development of the Brain
Link ID: 9261 - Posted: 08.22.2006

Jennifer Viegas, Discovery News — The horn-like jaws of the trap-jaw ant snap shut at a speed of 78 to 145 mph, qualifying as the fastest known moving body parts, according to new research. The jaws snap together with a force strong enough to hurl the ant 3 inches into the air and 8 1/2 inches away, the equivalent of a 5’6" human jumping 44 feet in the air and soaring for 132 feet. "The ants generate their extreme (jaw) speeds through the use of power amplification – a combination of springs and latches which allow the animals to store up and release energy within their own body," said lead author Sheila Patek, who indicated that the system has an "internal damping" mechanism that prevents the powerful snap from crushing the ant. "Trap-jaw ants slowly contract large muscles while a pair of latches keep the jaws open. Once the muscles are fully contracted, the latches are released and the jaws close explosively," she explained to Discovery News. The findings are published in this week’s Proceedings of the National Academy of Sciences. © 2006 Discovery Communications Inc.

Keyword: Miscellaneous
Link ID: 9260 - Posted: 06.24.2010

In this study, Ann Halbower and colleagues from Johns Hopkins University School of Medicine looked at 19 children aged 6-16 y with OSA and compared them with 12 healthy controls. The children underwent sleep tests, a battery of neuropsychological assessments, including IQ tests, and tests of executive function, and a group of children were assessed by magnetic resonance spectroscopy, a special form of brain imaging. Children with OSA had significantly lower scores than matched controls on full scale IQ tests and significantly lower performance on measures of executive function, including verbal working memory (sentence span) and word fluency. The special brain imaging (proton magnetic resonance spectroscopic imaging) showed decreases in the mean neuronal metabolite ratio of N-acetyl aspartate/choline in the left hippocampus and right frontal cortex, indicating possible neuronal injury in these areas. Symptomatic childhood sleep-disordered breathing includes a range of conditions in which children have difficulties with breathing when they are asleep. The conditions range from simple snoring to the most severe condition, obstructive sleep apnea (OSA). In children, OSA may be associated with enlarged tonsils, long-term allergy, or obesity. About two in every hundred children have OSA. The symptoms of OSA are loud snoring at night, disrupted, restless sleep, undue tiredness, and difficulties in concentration. If untreated, researchers believe that it may lead to a number of long-term problems with health and learning.

Keyword: Sleep; Intelligence
Link ID: 9259 - Posted: 08.22.2006

Kerri Smith Here's a cool strategy for relieving pain: scientists have found that cold temperatures and even cool-sensation chemicals can be used to treat chronic pain. Cold wet cloths and mint leaves pressed to the temple have long been used to put a damper on pain. But aside from the general numbing effect that ice can have on nerves, how cooling treatments work has remained a mystery. Now that the mechanism has been unpicked, researchers say, it could give new hope to sufferers of chronic pain, an often intractable condition affecting 50 million people in the United States alone. Some nerve-ends in the skin are known to hold receptors that are sensitive to temperature changes as well as foods frequently described as hot (such as chilli) or cold (such as menthol). One of these receptors, called TRPM8, can help the body to monitor temperatures between about 8 and 12 °C, as well as being activated by menthol-like chemicals, including a super-cooling chemical called icilin. Susan Fleetwood-Walker of the University of Edinburgh, UK, decided to investigate the link between these cold receptors and pain in rats. They first induced chronic pain in their animals by tying a thread around a thigh, and then either injected a very small dose of icilin into the spinal cord or had the rats stand in a shallow bath of the chemical. They then stroked the painful limb and checked the rats' response: those treated with icilin could withstand three times as much pressure. The findings are reported in Current Biology1. ©2006 Nature Publishing Group

Keyword: Pain & Touch
Link ID: 9258 - Posted: 06.24.2010

By LISA SANDERS, M.D. The white-haired man looked up from his newspaper as the doctor entered the hospital room. His eyes were a bright blue, and a warm, somewhat crooked smile lit up his face. “Sorry I can’t stand,” he said gallantly after the doctor introduced herself. “My legs are weak.” Dr. Merceditas Villanueva, a specialist in infectious diseases, returned the smile, then asked the patient to tell her about the weakness. He was 77. Never sick a day in his life — until the week before, on the Fourth of July. That day, also his wife’s birthday, the patient’s children and grandchildren had come to spend the day at his pool. In the late afternoon, the patient tried to get up to start the family dinner. “I do most of the cooking, especially on the holidays,” he told her in his lightly accented voice. “I’m Hungarian, and I like to cook the foods from home.” But that afternoon he was surprised to find that getting out of his chair was strangely difficult. He struggled to his feet, shrugging off the sons who hurried to help, and made his way slowly to the kitchen. But he hadn’t been able to cook that night — or any night since then. By the end of the week, he had no strength at all. “I couldn’t even take a step,” he said. “I was helpless.” His face eased into his lopsided smile once more. “My wife insisted I come to the hospital.” In the meantime, he also developed pain and swelling in his right knee, his left elbow and both feet. But, the patient added, joint pain was nothing new. The weakness, though, had never happened before; that was a little worrisome. Copyright 2006 The New York Times Company

Keyword: Miscellaneous
Link ID: 9257 - Posted: 06.24.2010

By GRETCHEN REYNOLDS Six years ago, Dr. Paul Savage was a pudgy mess. A 38-year-old emergency-room director in Waukegan, Ill., he weighed 267 pounds, suffered from high blood pressure and shortness of breath and had sallow skin that drooped in wattles around his chin. Today, at 44, he’s a new, unrecognizable man. Almost 100 pounds lighter, he boasts 12 percent body fat, a superhero jaw line and skin tone that seems almost incandescent. Savage says he owes much of his transformation to the self-administration of human growth hormone (H.G.H.). “I worked with a personal trainer and a nutritionist first,” he says. “I actually gained three pounds. Then I started growth hormone, and the weight dropped away.” Like a freshly hatched evangelist, Savage quit emergency-room medicine and in 2004 co-established a clinic in Chicago dedicated to hormone therapy, with an emphasis on H.G.H. His franchise, which operates under the name BodyLogicMD, serves about 1,500 people nationwide, many of whom pay upward of $15,000 for a yearly cycle of growth-hormone injections. The patient count rises by almost 100 each month. According to a 2005 article in The Journal of the American Medical Association, human growth hormone is being prescribed to tens of thousands of people each year at anti-aging or “age management” facilities like Savage’s. Those who take H.G.H. — including many doctors — say it can restore sagging physiques, flagging endurance and wilting libidos as well as cure depression and sharpen mental acuity. “I can’t believe everybody isn’t taking this,” says Dr. Darren Clair, 53, the founder of Vibrance Health Services, an age-management clinic in Beverly Hills, Calif., and himself a dedicated H.G.H. user. No one has yet claimed that H.G.H. reduces foot odor and freshens breath, though that could be coming. Copyright 2006 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 9256 - Posted: 06.24.2010

The compelling urge to satisfy one's hunger enlists structures throughout the brain, as might be expected in a process so necessary for survival. But until now, studies of those structures and of the feeding cycle have been only fragmentary--measuring brain regions only at specific times in the feeding cycle. Now, however, Ivan de Araujo, Duke University Medical Center, and colleagues report they have mapped the activity of whole ensembles of neurons in multiple feeding-related brain areas across a full cycle of hunger-satiety-hunger. Their findings, reported in the August 17, 2006, issue of the journal Neuron, published by Cell Press, open the way to understanding how these ensembles of neurons integrate to form a sort of distributed "code" that governs the motivation that drives organisms to satisfy their hunger. In their paper, Ivan de Araujo and colleagues implanted bundles of infinitesimal recording electrodes in areas of rat brain known to be involved in feeding, motivation, and behavior. Those areas include the lateral hypothalamus, orbitofrontal cortex, insular cortex, and amygdala. The researchers then recorded neuronal activity in those regions through a feeding cycle, in which the rats became hungry, fed on sugar water to satisfy that hunger, and then grew hungry again.

Keyword: Obesity
Link ID: 9255 - Posted: 08.21.2006

By JEFFREY KLUGER Few things are easier than telling a lie, and few things are harder than spotting one when it's told to us. We've been trying to suss out liars ever since Cain fibbed to God about murdering Abel. While God was not fooled--hearing the blood of Abel crying out from the land--the rest of us do not have such divine lie-detection gifts. But that doesn't mean we're not trying. In the post-9/11 world, where anyone with a boarding pass and a piece of carry-on is a potential menace, the need is greater than ever for law enforcement's most elusive dream: a simple technique that can expose a liar as dependably as a blood test can identify DNA or a Breathalyzer can nail a drunk. Quietly over the past five years, Department of Defense agencies and the Department of Homeland Security have dramatically stepped up the hunt. Though the exact figures are concealed in the classified "black budget," tens of millions to hundreds of millions of dollars are believed to have been poured into lie-detection techniques as diverse as infrared imagers to study the eyes, scanners to peer into the brain, sensors to spot liars from a distance, and analysts trained to scrutinize the unconscious facial flutters that often accompany a falsehood. At last they may be getting somewhere. Next month No Lie MRI of San Diego, a beneficiary of some of that federal largesse, will roll out a brain-scan lie-detection service it is marketing to government and industry. Another company, Cephos of Pepperell, Mass., hopes to follow within a few years. Copyright © 2006 Time Inc

Keyword: Stress; Brain imaging
Link ID: 9254 - Posted: 06.24.2010

By David F. Salisbury Keeping the lights on around the clock in neonatal intensive care units may interfere with the development of premature babies' biological clocks. That is the suggestion of a new study reported in the Aug. 21 issue of the journal Pediatric Research. The study, which was headed by Douglas McMahon, professor of biological sciences at Vanderbilt University and an investigator at the Vanderbilt Kennedy Center for Research on Human Development, reports that exposing baby mice to constant light keeps the master biological clock in their brains from developing properly and this can have a lasting effect on their behavior. "We are interested in the effects of light on biological clocks because they regulate our physiology extensively, and also have an important effect on our mood," McMahon says. "This study suggests that cycling the lights in NICUs may be better than constant lighting for premature babies' from the perspective of developing their internal clocks." Every year about 14 million low-weight babies are born worldwide and are exposed to artificial lighting in hospitals. "Today, we realize that lighting is very important in nursing facilities, but our understanding of light's effects on patients and staff is still very rudimentary," says William F. Walsh, chief of nurseries at Vanderbilt's Monroe Carrel Jr. Children's Hospital. "We need to know more. That is why studies like this are very important."

Keyword: Biological Rhythms; Chemical Senses (Smell & Taste)
Link ID: 9253 - Posted: 08.21.2006

University of Utah researchers isolated an unusual nerve toxin in an ocean-dwelling snail, and say its ability to glom onto the brain's nicotine receptors may be useful for designing new drugs to treat a variety of psychiatric and brain diseases. "We discovered a new toxin from a venomous cone snail that may enable scientists to more effectively develop medications for a wide range of nervous system disorders including Parkinson's disease, Alzheimer's disease, depression, nicotine addiction and perhaps even schizophrenia," says J. Michael McIntosh. Discovery of the new cone snail toxin will be published Friday, Aug. 25 in The Journal of Biological Chemistry by a team led by McIntosh, a University of Utah research professor of biology, professor and research director of psychiatry, member of the Center for Peptide Neuropharmacology and member of The Brain Institute. McIntosh is the same University of Utah researcher who – as an incoming freshman student in 1979 – discovered another "conotoxin" that was developed into Prialt, a drug injected into fluid surrounding the spinal cord to treat severe pain due to cancer, AIDS, injury, failed back surgery and certain nervous system disorders. Prialt was approved in late 2004 in the United States and was introduced in Europe last month.

Keyword: Neurotoxins
Link ID: 9252 - Posted: 06.24.2010

Jeff Hecht Public acceptance of evolutionHuman beings, as we know them, developed from earlier species of animals: true or false? This simple question is splitting America apart, with a growing proportion thinking that we did not descend from an ancestral ape. A survey of 32 European countries, the US and Japan has revealed that only Turkey is less willing than the US to accept evolution as fact. Religious fundamentalism, bitter partisan politics and poor science education have all contributed to this denial of evolution in the US, says Jon Miller of Michigan State University in East Lansing, who conducted the survey with his colleagues. "The US is the only country in which [the teaching of evolution] has been politicised," he says. "Republicans have clearly adopted this as one of their wedge issues. In most of the world, this is a non-issue." Miller's report makes for grim reading for adherents of evolutionary theory. Even though the average American has more years of education than when Miller began his surveys 20 years ago, the percentage of people in the country who accept the idea of evolution has declined from 45 in 1985 to 40 in 2005 (Science, vol 313, p 765). That's despite a series of widely publicised advances in genetics, including genetic sequencing, which shows strong overlap of the human genome with those of chimpanzees and mice. "We don't seem to be going in the right direction," Miller says. © Copyright Reed Business Information Ltd

Keyword: Evolution
Link ID: 9251 - Posted: 06.24.2010

By Rick Weiss A painstaking reanalysis of data collected in the 1980s from Vietnam War veterans confirms that post-traumatic stress disorder is a real and common psychiatric consequence of war, but it comes to the controversial conclusion that significantly fewer veterans were affected than experts have thought. The report's suggestion that one in five Vietnam veterans had the syndrome at some point in the first dozen years after the war -- as opposed to previous estimates as high as one in three -- drew praise from some experts as a valuable reassessment of an issue made timely by fresh waves of disturbed veterans coming back from Iraq. "It provides a more accurate gauge of the treatment needs," said Harvard University psychologist Richard J. McNally, who wrote a commentary accompanying the research in today's issue of the journal Science. But other experts and some veterans groups criticized the study, saying it used criteria so narrow that it excluded many vets who should have been included. "It uses a naive formulation of what represents a trauma exposure and so covers only a small percentage of people actually exposed to traumatic events," said Arthur Blank Jr., a Bethesda psychiatrist who treated soldiers in Vietnam and later served for 12 years as director of the federal network of counseling centers for combat veterans. © 2006 The Washington Post Company

Keyword: Stress
Link ID: 9250 - Posted: 06.24.2010

When he began his research on motion sickness, Tom Stoffregen thought finding test subjects would be difficult. After all, it's called motion sickness because it results in headaches, dizziness, and, often, literally being sick. What kind of people would be eager to find out what it takes to make them throw up? U students, it turns out. A lot of them. "Undergraduate students, as a class, are suicidal," Stoffregen says bluntly. "I'm flooded with volunteers." He suspects the mass offering of students may have something to do with misplaced pride. "People think, 'You can't make me throw up,'" he says. Unfortunately for them, Stoffregen, a professor in the College of Education and Human Development's School of Kinesiology, has invested a lot of time and effort into finding out exactly what brings on motion sickness. And, like an academic 007, he's got a license to test. Stoffregen's interest in motion sickness goes back to his childhood, when he was interested in space flight. He knew some astronauts suffered motion sickness, and after studying motion in graduate school and working for NASA, he wanted to find out why. People have been motion sick for thousands of years, says Stoffregen, conjuring visions of dizzy Neanderthals and green-faced Vikings, but no one is sure why. ©2006 Regents of the University of Minnesota.

Keyword: Miscellaneous
Link ID: 9249 - Posted: 06.24.2010

JOHANNESBURG - Dolphins may have big brains, but a South African-based scientist says lab rats and even goldfish can outwit them. Paul Manger of Johannesburg's University of the Witwatersrand says the super-sized brains of dolphins, whales and porpoises are a function of being warm-blooded in a cold water environment and not a sign of intelligence. "We equate our big brain with intelligence. Over the years we have looked at these kinds of things and said the dolphins must be intelligent," he said. "The real flaw in this logic is that it suggests all brains are built the same ... When you look at the structure of the dolphin brain you see it is not built for complex information processing," he told Reuters in an interview. A neuroethologist who looks at brain evolution, Manger's views are sure to cause a stir among a public which has long associated dolphins with intelligence, emotion and other humanlike qualities. They are widely regarded as one of the smartest mammals. But Manger, whose peer-reviewed research on the subject has been published in Biological Reviews of the Cambridge Philosophical Society, says the reality is different. Brains, he says, are made of neurons and glia. The latter create the environment for the neurons to work properly and producing heat is one of glia's functions. © 2006 MSNBC.com

Keyword: Intelligence; Evolution
Link ID: 9248 - Posted: 06.24.2010

At a speed-dating event in New York City, Adele Testani stands in the middle of a crowded bar with a whistle in her mouth and her eyes focused on her stopwatch. Moving from table to table, singles have only a few minutes to judge a potential mate as Testani, co-founder of HurryDate, ushers them along. Testani knows firsthand how body language can tell a lot, but is often misjudged. When she started dating her husband, she had him try out one of her events. Testani occasionally touches participants on the back to keep them moving. "And I kept doing that with my now husband, and he thought I was really into him," she recalls. Cornell University social psychologist David Dunning says it's sometimes difficult to decipher body language, like distinguishing between a smile and a smirk. Every day, he says, we deal with ambiguous images, and what we know as wishful thinking might affect not only how we interpret those images, but how we actually see them. "It's well established from evidence in everyday life and laboratory that people think what they want to think," he says. "We're taking this a step beyond. We're asking if desires and fears can influence literally what people physically see." David Dunning and study co-author Emily Balcetis told volunteers that a computer game would assign them either a letter or number to decide whether they would drink freshly-squeezed orange juice or an intentionally disgusting smoothie. © ScienCentral, 2000-2006.

Keyword: Vision; Attention
Link ID: 9247 - Posted: 06.24.2010