Michael Hopkin Chimps struggling to accumulate a large quantity of food deliberately keep themselves busy to avoid the temptation to gorge themselves straight away, researchers have found. The study shows that, like a shopaholic striving to resist the lure of the department store, our ape cousins welcome a distraction that takes the mind off the impulsive urge to splash out. Researchers at Georgia State University in Atlanta presented four chimps with a plastic container attached to a tube that gradually filled the container with candy. Opening it, however, would cut off the flow of food. Chimps were kept away from the candy machine but were allowed to observe it, so learning that the longer they waited, the bigger the treat they would get. But as many of us know, self-control doesn't come easily. Studies of human children have shown that the average five-year-old is rarely able to resist eating sweets, even if promised that abstinence will be rewarded with even more sweets later on. The Georgia researchers, Theodore Evans and Michael Beran, guessed that chimps would have a good chance at resisting the candies if given a range of toys and other distractions to play with. "We chose a set of items they are known to have an interest in," explains Evans. "They enjoy brushing their teeth, for example; we gave them magazines so they could look at the pictures; and they enjoy different types of fasteners, zips and clips that they can take apart." ©2007 Nature Publishing Group

Keyword: Attention; Obesity
Link ID: 10634 - Posted: 06.24.2010

Researchers have identified a new mechanism by which tricyclic antidepressants (TCAs) inhibit neurotransmitter transporters—a discovery that may improve the design of new antidepressants that are more effective than the TCAs currently on the market. TCAs, which have been prescribed for decades, have been largely supplanted by selective serotonin reuptake inhibitors because of their lack of specificity. Howard Hughes Medical Institute investigator Eric Gouaux at Oregon Health & Science University (OHSU) and colleagues began their studies with the goal of understanding how TCAs interact with their clinical target, sodium-coupled neurotransmitter transporters. These transporters mop up neurotransmitters from the synapse, the junction between neurons. Neurotransmitters are molecules that neurons use to communicate with neighboring neurons. TCAs work by inhibiting the reuptake of neurotransmitters by neurons. Disorders such as depression, epilepsy, autism, or obsessive-compulsive disorder can result from impaired function of sodium-coupled neurotransmitter transporters. Thus, these molecules are the target of a variety of drugs, including TCAs. It has been a great challenge, however, to understand precisely how these molecules function and interact with drugs. The problem, Gouaux said, is that the transporters found in humans are not amenable to study. © 2007 Howard Hughes Medical Institute.

Keyword: Depression
Link ID: 10633 - Posted: 06.24.2010

By RICHARD A. FRIEDMAN, M.D. Americans seem to like psychotherapy. Whether it’s for the mundane conflicts of everyday life or life-threatening illnesses like major depression, psychotherapy is widely viewed as a healthy, if not harmless, pursuit. Yet unlike most other medical treatments, psychotherapy can take considerable time. An infection can be cured in days, but remission of severe depression or anxiety disorder usually takes weeks or months, and a personality disorder typically requires years of intensive psychotherapy. So if the outcome may be months or years away, how can a person tell whether his psychotherapy is any good? It’s harder than you’d think. For one thing, people commonly equate feeling better with getting good treatment. But since psychiatric disorders fluctuate spontaneously with time, like most illnesses, many patients would get better even if they got no treatment at all. A patient getting bad psychotherapy might flourish, while another patient getting exemplary treatment might suffer terribly. Judging from one of the largest surveys of psychotherapy to date, most Americans who try psychotherapy think it is beneficial. In its 1994 annual questionnaire, Consumer Reports asked readers about their experience in psychotherapy. Of 7,000 subscribers who responded to the mental health questions, 4,100 saw mental health professionals. Most reported feeling better with therapy, regardless of whether they were treated by a psychologist, a psychiatrist or a social worker. And those in long-term therapy reported more improvement than those in short-term therapy. Copyright 2007 The New York Times Company

Keyword: Depression
Link ID: 10632 - Posted: 06.24.2010

By Robert Roy Britt Researchers presented further evidence today that obesity in some cases might be contagious. A common virus, implicated in previous studies as a possible cause of obesity, was found in lab tests to transform adult stem cells obtained from fat tissue into fat cells. A gene in the virus has now been found to be the likely culprit. “We’re not saying that a virus is the only cause of obesity, but this study provides stronger evidence that some obesity cases may involve viral infections,” said Dr. Magdalena Pasarica of Louisiana State University. “Not all infected people will develop obesity,” Pasarica said. “We would ultimately like to identify the underlying factors that predispose some obese people to develop this virus and eventually find a way to treat it.” The virus is a human adenovirus-36 (Ad-36), known to cause respiratory and eye infections. Previous research has shown that it causes fat to accumulate in animals, and other work found that 30 percent of obese people were infected with the Ad-36 virus in comparison to 11 percent of lean people. But no one has shown clearly that the virus actually causes fat levels to increase in human cells. In the new study, Pasarica and her associates obtained adult stem cells from fatty tissue of patients who had undergone liposuction. Half of the stem cells were exposed to the virus and the other half were not. Most of the virus-infected cells developed into fat cells, while the non-infected cells did not. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Obesity
Link ID: 10631 - Posted: 06.24.2010

Researchers found that cats' memories were much longer after stepping over an obstacle, rather than just seeing an object, says a study published Monday in the science journal Current Biology. The scientists who led the study, David A. McVea and Keir G. Pearson, from the Department of Physiology at the University of Alberta, conducted a simple experiment to measure the felines' memories. Audrey, a current resident of the Hemingway House in Key West, Fla. (Wilfredo Lee/Associated Press) They halted the cats' walking after their forelegs, but not hind legs, had cleared an obstacle. Then they distracted the animals with food, and lowered the obstacle into the walking surface. The next step revealed whether the cat remembered stepping over the "disappearing" obstacle. The researchers then repeated the experiment to find out if the cats remembered what they saw, versus what they did. But this time they stopped the cats just before they made their first step. McVea, told CBC News that this form of memory is equally vital to humans. "Although we use vision extensively to guide our walking, we don't look at our feet as we walk — we look three or four steps ahead and remember the terrain." © CBC 2007

Keyword: Learning & Memory
Link ID: 10630 - Posted: 06.24.2010

By BENEDICT CAREY In academic feuds, as in war, there is no telling how far people will go once the shooting starts. Alice Dreger, an ethics scholar, investigated the accusations against Dr. Bailey. Earlier this month, members of the International Academy of Sex Research, gathering for their annual meeting in Vancouver, informally discussed one of the most contentious and personal social science controversies in recent memory. The central figure, J. Michael Bailey, a psychologist at Northwestern University, has promoted a theory that his critics think is inaccurate, insulting and potentially damaging to transgender women. In the past few years, several prominent academics who are transgender have made a series of accusations against the psychologist, including that he committed ethics violations. A transgender woman he wrote about has accused him of a sexual impropriety, and Dr. Bailey has become a reviled figure for some in the gay and transgender communities. To many of Dr. Bailey’s peers, his story is a morality play about the corrosive effects of political correctness on academic freedom. Some scientists say that it has become increasingly treacherous to discuss politically sensitive issues. They point to several recent cases, like that of Helmuth Nyborg, a Danish researcher who was fired in 2006 after he caused a furor in the press by reporting a slight difference in average I.Q. test scores between the sexes. “What happened to Bailey is important, because the harassment was so extraordinarily bad and because it could happen to any researcher in the field,” said Alice Dreger, an ethics scholar and patients’ rights advocate at Northwestern who, after conducting a lengthy investigation of Dr. Bailey’s actions, has concluded that he is essentially blameless. Copyright 2007 The New York Times Company

Keyword: Sexual Behavior
Link ID: 10629 - Posted: 06.24.2010

By GEORGE JOHNSON The reason he had picked me from the audience, Apollo Robbins insisted, was that I’d seemed so engaged, nodding my head and making eye contact as he and the other magicians explained the tricks of the trade. I believed him when he told me afterward, over dinner at the Venetian, that he hadn’t noticed the name tag identifying me as a science writer. But then everyone believes Apollo — as he expertly removes your wallet and car keys and unbuckles your watch. It was Sunday night on the Las Vegas Strip, where earlier this summer the Association for the Scientific Study of Consciousness was holding its annual meeting at the Imperial Palace Hotel. The organization’s last gathering had been in the staid environs of Oxford, but Las Vegas — the city of illusions, where the Statue of Liberty stares past Camelot at the Sphinx — turned out to be the perfect locale. After two days of presentations by scientists and philosophers speculating on how the mind construes, and misconstrues, reality, we were hearing from the pros: James (The Amazing) Randi, Johnny Thompson (The Great Tomsoni), Mac King and Teller — magicians who had intuitively mastered some of the lessons being learned in the laboratory about the limits of cognition and attention. “This wasn’t just a group of world-class performers,” said Susana Martinez-Conde, a scientist at the Barrow Neurological Institute in Phoenix who studies optical illusions and what they say about the brain. “They were hand-picked because of their specific interest in the cognitive principles underlying the magic.” She and Stephen Macknik, another Barrow researcher, organized the symposium, appropriately called the Magic of Consciousness. Copyright 2007 The New York Times Company

Keyword: Attention
Link ID: 10628 - Posted: 06.24.2010

By ALICE PARK As a personality trait, shyness probably ranks as one of the more benign characteristics that someone can possess, but new research suggests that at least some forms of shyness may have violent, and often deadly, consequences. Analyzing eight school shootings over the past decade, psychologist Bernardo Carducci and his team at Indiana University found that the young shooters in these incidents shared nearly all of 29 personality and behavior characteristics that Carducci categorizes as cynical shyness. This form, says Carducci, who directs the Shyness Research Institute, differs from normal shyness in that sufferers disconnect with others when their efforts at socialization are rebuffed. "These are people who want to be with others but who are rejected in a very harsh way," he says. While normally shy people would continue to try, and eventually succeed, in connecting with others, cynically shy individuals internalize the rejection and alienate themselves. "As they develop a sense of disconnect, they move away from people, and as they move away from people, that makes it easier for them to hurt them. These people are becoming a cult of one," he says. Carducci presented his hypothesis at the annual meeting of the American Psychological Association on Saturday, and notes that while his study did not include the most recent and deadliest school shooting, at Virginia Tech earlier this year, gunman Seung Hui Cho possessed 77% of the characteristics that Carducci isolated. These include social withdrawal, preoccupation with weapons and violence, anger or violence reflected in his work or journal, and hostility toward classmates and teachers. © 2007 Time Inc

Keyword: Aggression
Link ID: 10627 - Posted: 06.24.2010

By Benjamin Lester Walk into the little girls' aisle at a toy store, and you'll be inundated with pink. We take for granted gender differences in color preference, but for more than 100 years, studies have failed to find a biological basis for the disparity. New research confirms that girls go for red whereas guys do not and links the mechanism to the biology of vision. Our color likes and dislikes may be a remnant of the different roles that men and women played in our distant hunter-gatherer past. Studies from as long ago as 1897 have hinted at differences in color preference between genders, suggesting that more females preferred reds than did males. But the data were murky and inconsistent, according to experts. Hoping to clear the air, neuroscientists Anya Hurlbert and Yazhu Ling of Newcastle University in the U.K. performed an experiment on 171 British Caucasians and 38 recent immigrants from China aged 20 to 26. Each subject chose his or her favorite from a series of color pairs on a computer screen. Humans judge color on two scales--one red-green and one blue-yellow. Hurlbert and Ling assigned each color values on these same two scales and compared each gender's preferences. In the 21 August issue of Current Biology, the researchers report that, on the yellow-blue scale, males and females both went for blue--U.K. females much more strongly than their male counterparts. On the red-green scale, however, females preferred red, whereas males opted for green--a difference that held true for Caucasian and Chinese subjects, although in Chinese females the trend was much more pronounced. © 2007 American Association for the Advancement of Science

Keyword: Sexual Behavior
Link ID: 10626 - Posted: 06.24.2010

Mary Muers Researchers have found a simple physical symptom that accompanies the early, subtle brain changes that lead to dementia. Women who will go on to develop dementia begin to lose weight at least ten years before diagnosis, say researchers at the Mayo Clinic in Rochester, Minnesota. While the symptom of weight loss is too common to serve as a usable early warning sign for mental decline, researchers hope other such physical changes could be used to spot dementia before memory loss sets in. David Knopman, who led the study published in Neurology1 today, thinks the women may have shed the weight because creeping damage in their brains caused them to lose interest in food. He speculates that the disease could cause apathy or dull the senses of taste and smell, making food less appealing. Neurologists have long suspected that conditions such as Alzheimer's disease begin to develop 10-20 years before diagnosis. But spotting such early changes has proven difficult. This is one of only a few studies to make a link between physical symptoms and emerging dementia. "It's an interesting development in terms of how we think about dementia," says Robert Stewart, an epidemiologist at London's Institute of Psychiatry who has previously found a hint of a link between dementia and weight loss2. ©2007 Nature Publishing Group

Keyword: Alzheimers; Obesity
Link ID: 10625 - Posted: 06.24.2010

Ewen Callaway The body's clock may lose track of time during winter hibernation, scientists have found in a species of hamster. The genes responsible for regulating circadian rhythms in the brain normally follow a 24-hour cycle, with their activity waxing and waning in step with day and night. But what happens during hibernation? Brain activity resembles that of deep slumber, and the body slows its metabolism to a crawl. The internal temperature of arctic ground squirrels, for instance, can plummet below freezing. It's thought that hibernation evolved from sleep as a way to save energy during lean winter months. Some studies have hinted that factors such as body temperature continue to oscillate up and down in a daily cycle during this winter period, although not nearly so much as during normal conditions. But no one had tapped directly into the brain or looked at the genes that control the body clock to see what was happening there. Biologists Florent Revel and Paul Pévet of Louis Pasteur University in Strasbourg, France, investigated hibernation's effect on the brain in European hamsters, which normally stay burrowed in their nests between December and March, rarely venturing above ground. During these months they follow a regular schedule: three to four days of hibernation followed by two to three days of activity. ©2007 Nature Publishing Group

Keyword: Biological Rhythms
Link ID: 10624 - Posted: 06.24.2010

Roxanne Khamsi Paedophiles may have reduced concentrations of nerve cells in key areas of the brain compared to normal people, according to a study published by German researchers. The study could have significant legal implications, experts say, because it hints at a direct link between brain development and criminal behaviour. The causes of paedophilia are not understood and even diagnosis is controversial (see Sex offenders: Throwing away the key). Boris Schiffer and colleagues of the University of Duisburg-Essen in Germany studied 18 convicted paedophiles with a history of repeatedly abusing children younger than 14. Schiffer scanned their brains using magnetic resonance imaging and compared the scans to those of normal men of matching ages. The scans revealed that the paedophiles had less "grey matter" – tissue with a high concentration of nerve cells – in several areas of the brain. The men in Schiffer's study had an average IQ of about 90, which is not considered abnormally low, compared to an average of 100 for the control group. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Aggression
Link ID: 10623 - Posted: 06.24.2010

CBC News It's long been thought that stress is harmful to your health, but a new study finds chronic stress may increase a person's risk of developing or accelerating a neurodegenerative disease like multiple sclerosis. Researchers have demonstrated for the first time that inflammation brought on by stress leads to the worsening of the mouse equivalent of MS. In studies, stressed mice produced a cytokine which is released during stress. That cytokine increased the severity of an MS-like illness in the mice. CBC The findings were presented Friday at the annual convention of the American Psychological Association. In the study, scientists simulated stressful situations on mice infected with Theiler's murine encephalomyelitis (TMEV), an acute infection of the central nervous system which is followed by a chronic autoimmune disease similar to that seen in humans with MS. Another group of mice was also infected but not exposed to stress. Researchers found that the stressed mice produced a cytokine — interleukin-6 (IL-6) — which is released during stress and regulates the part of the immune system that fights infection. IL-6 increases the severity of the MS-like illness. © CBC 2007

Keyword: Multiple Sclerosis; Stress
Link ID: 10622 - Posted: 06.24.2010

By GRETCHEN REYNOLDS The Morris water maze is the rodent equivalent of an I.Q. test: mice are placed in a tank filled with water dyed an opaque color. Beneath a small area of the surface is a platform, which the mice can’t see. Despite what you’ve heard about rodents and sinking ships, mice hate water; those that blunder upon the platform climb onto it immediately. Scientists have long agreed that a mouse’s spatial memory can be inferred by how quickly the animal finds its way in subsequent dunkings. A “smart” mouse remembers the platform and swims right to it. In the late 1990s, one group of mice at the Salk Institute for Biological Studies, near San Diego, blew away the others in the Morris maze. The difference between the smart mice and those that floundered? Exercise. The brainy mice had running wheels in their cages, and the others didn’t. Scientists have suspected for decades that exercise, particularly regular aerobic exercise, can affect the brain. But they could only speculate as to how. Now an expanding body of research shows that exercise can improve the performance of the brain by boosting memory and cognitive processing speed. Exercise can, in fact, create a stronger, faster brain. This theory emerged from those mouse studies at the Salk Institute. After conducting maze tests, the neuroscientist Fred H. Gage and his colleagues examined brain samples from the mice. Conventional wisdom had long held that animal (and human) brains weren’t malleable: after a brief window early in life, the brain could no longer grow or renew itself. The supply of neurons — the brain cells that enable us to think — was believed to be fixed almost from birth. As the cells died through aging, mental function declined. The damage couldn’t be staved off or repaired. Copyright 2007 The New York Times Company

Keyword: Neurogenesis
Link ID: 10621 - Posted: 06.24.2010

By GINA KOLATA The havoc diabetes wreaks is clear. But researchers are puzzled by many aspects of the disease. Why, for example, are most people with Type 2 diabetes overweight or obese, yet most overweight or obese people do not have diabetes? One clue may lie in the fat cells themselves. The cells release fat and breakdown products of fat — triglycerides and free fatty acids — into the blood. These substances may make cells less able to respond to insulin, increasing the body’s demand for the hormone. Another clue is a paradoxical finding about a hormone, adiponectin, made by fat cells. Adiponectin makes cells more responsive to insulin. “Oddly enough,” said Dr. C. Ronald Kahn, a diabetes researcher and professor of medicine at Harvard Medical School, “the fatter people become, the less adiponectin their fat cells produce.” So one way obesity might increase the risk that a person will develop diabetes is by leading to a release of more fatty acids and a decline in adiponectin. This would lead to more insulin resistance and a demand for more insulin. If that demand cannot be met, the result, eventually, would be diabetes. But figuring out why obesity predisposes some people to diabetes is only part of the puzzle. Researchers also are struggling with a fundamental question. Why does high blood sugar lead to any of the disease’s complications — heart disease, stroke, nerve damage, kidney damage and sight-threatening eye damage? Copyright 2007 The New York Times Company

Keyword: Obesity
Link ID: 10620 - Posted: 06.24.2010

By Paul Raeburn Two years ago Katherine M. Flegal, a re­search­er at the Centers for Disease Control and Prevention, did a new statistical analysis of national survey data on obesity and came to a startling conclusion: mildly overweight adults had a lower risk of dying than those at so-called healthy weights. Decades of research and thousands of studies have suggested precisely the opposite: that being even a little overweight is bad and that being obese is worse. The distinction between overweight and obese—which are sometimes both classified under the rubric of obesity—can be confusing. It relates to the measure called body mass index (BMI), derived by dividing one’s weight in kilograms by the square of one’s height in meters. A myriad of Internet-based calculators will handle the math for you. The only thing to remember is that a BMI of at least 25 but less than 30 is considered overweight, and one of 30 or more is characterized as obese. The long-established conventional wisdom holds that Americans carrying excess fat are at increased risk of death from heart disease, diabetes and various kinds of cancer. And those who do not die of obesity-related ailments can possibly look forward to a variety of other unpleasant consequences of their weight, including diabetes and its complications, such as the loss of an arm or leg, blindness and kidney failure. That has been the consensus view of most experts for decades, and it has not changed. © 1996-2007 Scientific American, Inc

Keyword: Obesity
Link ID: 10619 - Posted: 06.24.2010

By Kristin Leutwyler Ozelli Nora D. Volkow is director of the National Institute of Drug Abuse. Before her appointment in 2003, she held various positions at Brookhaven National Laboratory and also served as professor of psychiatry and associate dean for the medical school at Stony Brook University. In her research, she was first to use imaging technology to investigate neurochemical changes associated with addiction Mounting evidence shows that compulsive eating and drug abuse engage some of the same brain circuits in similar ways, offering a new angle for understanding and treating obesity. In an interview with Scientific American, Nora D. Volkow, director of the National Institute on Drug Abuse and a pioneer in the study of addiction, explains. How do foods and drugs affect the brain in the same way? The system in the brain that both drugs and food activate is basically the circuitry that evolved to reward behaviors that are essential for our survival. One of the reasons why humans are attracted to food is because of its rewarding, pleasurable properties. When we experience pleasure, our brains learn to associate the pleasurable experience with the cues and conditions that predict it. In other words, the brain remembers not just what the food tasted like but also the sensation of pleasure itself, and the cues or behaviors that preceded it. That memory becomes stronger and stronger as the cycle of predicting, seeking and obtaining pleasure becomes more reliable. When you remember that food, you also automatically expect the pleasure that comes from it. So when you like something very much, the mere fact of being re-exposed to it, even if it is out of reach, will trigger the desire to get it. In scientific terms, we call this process conditioning. © 1996-2007 Scientific American, Inc.

Keyword: Obesity; Drug Abuse
Link ID: 10618 - Posted: 06.24.2010

A Swiss woman who fell off her bicycle has yielded a unique insight into how auditory hallucinations are generated. The woman suffered damage to the part of the brain where speech is generated and could speak only in short, stunted words and sentences. Five months later, when she suddenly developed epilepsy, she began "hearing" voices with the same speech impediments as herself. "She initially heard her own voice speaking aloud, then the voices of hospital staff," says Daniela Hubl at the University Hospital of Psychiatry in Bern, Switzerland, a member of the team that treated her. "They had the same speech impediments as she did. It proves that the voices were generated in the language areas of the patient's own brain." The hallucinations disappeared when the woman received drugs to control her epilepsy (The Lancet, vol 370, p 538). Hubl believes the case is unique and supports more strongly than ever the scientific consensus that "voices" and other hallucinations experienced by people with conditions like schizophrenia are generated within their own brains. From issue 2617 of New Scientist magazine, 20 August 2007, page 16 © Copyright Reed Business Information Ltd.

Keyword: Language
Link ID: 10617 - Posted: 06.24.2010

US scientists may have discovered why long nerve cells do not break when you move or stretch your limbs. Experiments in worms showed that when a protein called beta spectrin is missing, nerve cells are brittle and break, leading to paralysis. The finding may help to explain why people with a condition called spinocerebellar ataxia progressively lose co-ordination and movement. The University of Utah study is in the Journal of Cell Biology. Humans have four genes responsible for the production of beta spectrin protein. Recent studies have shown that people with a condition called spinocerebellar ataxia type 5, a neurodegenerative disease that develops between the ages of 10 and 68, have a mutation in one of the genes. It was previously thought that the mutation in this protein meant cells could not communicate properly because the necessary proteins would not be anchored in place. But research by Professor Michael Bastiani and colleagues at the University of Utah suggests that a mutation in or absence of the protein causes long nerve fibres (axons) to lose their flexibility and break. When nematode worms were bred without beta spectrin their nerve axons died over time and caused paralysis. In worm embryos only 3% of nerve cells were broken or defective but that grew to 60% by the time the worms were a day old, suggesting the protein is not responsible for initial growth of nerve cells but for preventing breakage later on. Professor Bastiani said the team found it "incredible" that the one protein was responsible for preventing nerves breaking in your whole body. "The entire functioning of the nervous system depends on these wire-like axons between nerve cells," he said. (C)BBC

Keyword: Development of the Brain
Link ID: 10616 - Posted: 08.18.2007

By David Biello Sugar and spice and everything nice hold no interest for a cat. Our feline friends are only interested in one thing: meat (except for saving up the energy to catch it by napping, or a round of restorative petting) This is not just because inside every domestic tabby lurks a killer just waiting to catch a bird or torture a mouse, it is also because cats lack the ability to taste sweetness, unlike every other mammal examined to date. The tongues of most mammals hold taste receptors—proteins on the cellular surface that bind to an incoming substance, activating the cell's internal workings that lead to a signal being sent to the brain. Humans enjoy five kinds of taste buds (possibly six): sour, bitter, salty, umami (or meatiness) and sweet (as well as possibly fat). The sweet receptor is actually made up of two coupled proteins generated by two separate genes: known as Tas1r2 and Tas1r3. When working properly, the two genes form the coupled protein and when something sweet enters the mouth the news is rushed to the brain, primarily because sweetness is a sign of rich carbohydrates—an important food source for plant-eaters and the nondiscriminating, like humans. But cats are from the noble lineage Carnivora and, unlike some of its lesser members, such as omnivorous bears or, even more appalling, herbivorous pandas, they exclusively eat meat. © 1996-2007 Scientific American, Inc.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 10615 - Posted: 06.24.2010