Kenneth C. Catania I’ve been trapping star-nosed moles for two decades to study their behavior and anatomy, so I am used to the disappointment of finding an empty trap. But one trap I set about twelve years ago disappointed me in another way. I had placed it in a wetland to catch a mole, but found that another small mammal had the nerve to get caught. Recognizing that it was a North American water shrew, I released it at the edge of a nearby stream, wondering just how good it could possibly be at swimming (it doesn’t look very different from its landlubber relatives). I was amazed to see it shoot straight down into a deep pool of water, swim across the stream, and disappear into submerged vegetation on the other side. It seemed more like a fish than a mammal. I never forgot the sight. Although my investigations of star-nosed moles continued to occupy me for years, eventually, in collaboration with Kevin L. Campbell and James F. Hare, biologists at the University of Manitoba, I set out to learn more about the North American water shrew, Sorex palustris. It is not only (at little more than half an ounce) the world’s smallest mammalian diver, but also a predator with remarkable abilities to sense and capture prey. To be fair, you’ll never have to worry about one latching onto your foot and dragging you into a lake. But I have come to think of water shrews as the great white sharks of their diminutive domain. Shrews are members of the order Insectivora, which also includes moles and hedgehogs. Although they may look somewhat like mice, they are only distantly related to rodents. There are three subfamilies of shrews; the North American water shrew belongs to the Soricinae subfamily, the so called red-toothed shrews. This group gets its name from iron deposits in the animals’ teeth that are thought to provide added strength to the enamel (tooth wear is a major problem for shrews, because their teeth don’t grow continuously, as those of rodents do). © Natural History Magazine, Inc., 2008

Keyword: Chemical Senses (Smell & Taste)
Link ID: 11491 - Posted: 06.24.2010

There is strong evidence that exposure to pesticides significantly increases the risk of Parkinson's disease, experts believe. It comes as another study, published in the BMC Neurology journal, has made the link to the neurological disease. The US researchers found those exposed to pesticides had a 1.6 times higher risk after studying 600 people. Experts said it was now highly likely pesticides played a key role - albeit in combination with other factors. The disorder, which normally develops later in life and can affect movement and talking, is also influenced by genetic factors. Several gene defects have been identified, but these are thought to be rare and only account for a small proportion of the 120,000 people affected by the disease in the UK. The US team, which involved scientists from Duke University, Miami University and the Udall Parkinson's Disease Research Center of Excellence, quizzed 319 patients about their pesticide use. The answers were compared to over 200 family members and other controls who did not have the disease. Related individuals were chosen as they would share many environmental and genetic backgrounds in a bid to isolate the impact of the pesticides. They found those exposed to pesticides had a 1.6 times greater risk of developing the disease. Heavy use, classed as over 200 days exposure over a lifetime, carried over double the risk. And the study also revealed herbicides and insecticides were the pesticides most likely to increase risk. (C)BBC

Keyword: Parkinsons; Neurotoxins
Link ID: 11490 - Posted: 03.29.2008

Rats are able to learn from experience and apply what they have learned to new situations, similar to the way toddlers learn language, new research from the United Kingdom suggests. In a report in the March 28 edition of the journal Science, researchers at the University of Oxford report that rats were able to learn a simple, three-step audio or visual sequence and connect the pattern, associated with food, to a different setting. New research from scientists in the United Kingdom suggests that rats are capable of abstract thought. "These experiments show that rats can learn simplified rules and apply these rules to novel stimuli," wrote the researchers. "Even if the cognitive mechanism that allows the rats' behaviour is found to be dissimilar to that found in humans, it does seem that both species have evolved means of solving similar information problems, in this case, the transfer of overall sequence relations." Previous studies have suggested that infants, primates and birds are able to identify sequences, the researchers wrote in their report, but the question of whether animals other than humans are able to learn and apply rules has been contested. © CBC 2008

Keyword: Learning & Memory
Link ID: 11489 - Posted: 06.24.2010

Suzy Allman Public health experts generally agree that after clean water and flush toilets, the most important health advances in history have been vaccinations. Shots against measles, diphtheria, whooping cough, tetanus, polio, mumps, rubella, chicken pox, flu, hepatitis and some causes of childhood meningitis, pneumonia and diarrhea have saved more lives than all the “miracle drugs” of the latter half of the 20th century — antibiotics like penicillin, antivirals like drugs to fight AIDS and flu, and so on. In addition, vaccination is one of the leading reasons that many families in the West now feel comfortable having only two or three children: they can be reasonably certain that the children will survive childhood. According to a large historical study by the Centers for Disease Control and Prevention released in November 2007, death rates for 13 diseases that can be prevented by childhood vaccinations were at all-time lows in the United States. The study looked at hospital and death records going back to 1900 and estimated death rates before various vaccines were invented. In nine of the diseases, rates of hospitalization or death had declined more than 90 percent. For three — smallpox, diphtheria and polio — death rates had dropped by 100 percent. Copyright 2008 The New York Times Company

Keyword: Autism; Neuroimmunology
Link ID: 11488 - Posted: 06.24.2010

By Nikhil Swaminathan A new study indicates that the genetic culprits behind schizophrenia may be much less common than previously believed. Researchers report this week in Science that a rare but devastating change in one of several different genes may dramatically increase the risk of developing the debilitating brain disorder affecting 1 percent of the world's population and marked by psychotic behavior, hallucinations and delusions. Until now, most scientists believed that it was likely that a cluster of relatively common genetic mutations was to blame. "We're not saying that our results themselves are irrefutable proof that schizophrenia is all rare mutations," says study co-author Jonathan Sebat, a geneticist at Cold Spring Harbor Laboratory in Long Island, N.Y. "It is simply that in many schizophrenia cases, much of a patient's individual risk can be accounted for by a 'sledgehammer' mutation." Until recently, researchers trying to unravel the mysterious disease searched the genomes of schizophrenia patients for flaws not present in the genes of healthy people. Their probes turned up a few possible genetic suspects, but the findings were contradicted by those from other studies. In addition, candidate mutations typically only showed up in no more than 10 percent of schizophrenia sufferers sampled. The new study identifies more than 20 genes that may trigger the disease. If researchers can positively link any or all of these genes to the disease, it would set the stage for development of new therapies. © 1996-2008 Scientific American Inc.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 11487 - Posted: 06.24.2010

Tina Hesman Saey A genetic quirk could help cheating athletes beat drug tests and could unfairly taint fair players. The genetic variation affects an enzyme that processes testosterone. Testosterone is naturally made in the body by both men and women, although it is primarily known as a male sex hormone. In order to distinguish between naturally present hormone and synthetic testosterone from steroid use, drug tests measure a ratio of two chemicals found in urine. One chemical, epitestosterone glucuronide (EG), is made at a constant level in the body, regardless of testosterone levels. The other chemical, testosterone glucuronide (TG), is a testosterone by-product. Testers measure the ratio of TG to EG. Any amount of TG greater than four times the level of EG is considered a red flag for doping. An enzyme called UGT2B17 adds a chemical to testosterone to prepare it for secretion in the urine. A group of scientists in Sweden found that some people completely lack the gene that produces UGT2B17, and this difference could affect results of doping tests. ©2008 Society for Science & the Public

Keyword: Hormones & Behavior; Genes & Behavior
Link ID: 11486 - Posted: 06.24.2010

By Clara Moskowitz You're at a crowded party with chaos and noise all around but somehow you focus on what your date says. Scientists have long puzzled over how we do this — filter out unimportant noise to concentrate on one voice out of many in a room. At first, researchers suggested the brain distinguishes different sources of sound by analyzing which direction they come from. But people can still focus on a single voice among many over the telephone when they can't tell where the speaker is in relation to other speakers. Now scientists have discovered that the auditory system probably sorts different sources of sound based on their unique pitch and suppresses less important ones. "We think this is the major way the brain can do this cocktail party phenomenon," said Holger Schulze, a neuroscientist at the Leibniz-Institute for Neurobiology in Magdeburg, Germany. He and his colleagues studied gerbils that have a very similar hearing mechanism to humans, so they think the findings likely apply to humans as well. "It has been known for 20 or 30 years that it is possible without directional information to do the job," Schulze said. "But we didn't know how it works, where in the brain this happens. Now we know it's in one small area within the auditory cortex." © 2008 LiveScience.com.

Keyword: Hearing; Attention
Link ID: 11485 - Posted: 06.24.2010

Snakes inspire disgust in many people, and downright terror in others. In fact, snake phobia, or ophidiophobia, is the one of the most common phobias on earth. Now psychology researchers studying toddlers say that avoiding snakes may be an evolutionary adaptation that's slithered its way into our genes. The University of Virginia's Judy DeLoache says her own personal snake fear led her to this research. "I have a very intense fear of snakes. In fact, I would pretty much say I have a snake phobia. I always have, ever since I can remember." DeLoache, an expert on how children see and interpret symbols, began with the theory that spotting a snake is a survival skill that may have been passed on in peoples' genetic code. This skill most likely extends far back into our evolutionary past. As DeLoache explains, "any human that could quickly detect the presence of a snake and thereby avoid being bitten by one and possibly poisoned, would have been more likely to survive, would have been more likely to pass on their genes to their offspring." Because snakes are found all over the globe, this adaptation would have continued to be useful to our ancestors as they settled in different areas of the world. If humans truly do have an inherited tendency to quickly locate snakes in their environment, they may also readily fear snakes as well. A threatening object, like a snake, would elicit more of a response than a non-threatening object, like a tree or a rock. Eventually, this could make it more likely for some people to develop an irrationally intense fear of snakes. © ScienCentral, 2000-2008.

Keyword: Emotions
Link ID: 11484 - Posted: 06.24.2010

-- It's late at night, you are in a town you don't know well, and all the restaurants are closing. Famished, you spot a stall that will sell you a small snack. Should you take the snack or venture further, hoping to find a place that will serve you a hearty meal but knowing that you may also find nothing? Most of us would go for the safe option -- we prefer to have at least a little to eat rather than take the risk of going hungry if the quest for a bigger reward goes awry. Scientists have carried out an innovative experiment among our closest relatives, chimpanzees and bonobos, in an attempt to explain why this is so. In a paper appearing on Wednesday in Biology Letters, published by Britain's Royal Society, U.S. and German animal behaviorists recruited five chimps and five bonobos at a primate research centre at Leipzig Zoo, eastern Germany. The apes had to choose between two upside-down bowls. One was the "safe" bowl, which always covered four grape halves. The other was the "risky" bowl, which covered anything between one and seven grape halves. Chimpanzees turned out to be big risk-takers, invariably tempted to go for the grand prize even if this also meant frequent disappointment. © 2008 Discovery Communications

Keyword: Emotions
Link ID: 11483 - Posted: 06.24.2010

Katharine Sanderson Find it hard to identify the smell? A teaching session backed by electric shocks might teach you to learn the difference. Wen Li, at Northwestern University in Evanston, Illinois, and her colleagues, have shown that the brain can be shocked into sniffing out the differences between molecules that they would not usually be able to distinguish by smell. The result confirms that 'fear conditioning' can be used to awaken the highest capacity of human abilities, and shows that people can spot smell differences once thought perceivable only to other animals. Li works in the neurology lab of Jay Gottfried, which has a history of investigating the sense of smell and how this affects perception. In this experiment, they looked at people's ability to smell the difference between enantiomers — non-superimposable mirror images of molecules. Although rats can usually tell these molecules apart, humans can't always do so. The molecule carvone, for example, smells to people like caraway when in one form, and like spearmint when in its mirror image. But most enantiomers smell identical to people. No one knows why humans' sense of smell differs so much from rats'. Some suggest that modern humans have lost a fine-tuned sense of smell as this sense is not generally needed for day-to-day survival. So the team set out to see whether humans really are missing something, or whether they simply aren't trying hard enough.

Keyword: Chemical Senses (Smell & Taste); Emotions
Link ID: 11482 - Posted: 06.24.2010

People with schizophrenia have higher rates of rare genetic deletions and duplications that likely disrupt the developing brain, according to studies funded in part by the National Institutes of Health. These tiny anomalies were found in 15 percent of adult onset schizophrenia patients and 20 percent of child and adolescent onset patients, compared with only 5 percent of healthy participants. Collectively, the mutations carried by patients were significantly more likely than those in healthy participants to disrupt genes involved in brain development — potentially implicating hundreds of genes in the illness, which affects about 1 percent of adults. "This is an important new finding in the genetics of schizophrenia," said NIMH Director Thomas R. Insel, M.D. "Identifying genes prone to harboring these mutations in brain development pathways holds promise for treatment and prevention of schizophrenia, as well as a wide range of other neurodevelopmental brain disorders." The prevailing genetic model of schizophrenia implicates common variants of certain suspect candidate genes, each exerting modest effects, in interaction with each other and environmental factors. This hypothesis holds that risk stems from common variations in the sequence of the genetic code that result in altered protein products.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 11481 - Posted: 06.24.2010

By ERIC WILSON Last September, Kate and Laura Mulleavy, the sibling designers of Rodarte, received a phone call from a Vogue editor who suggested that they see a trainer and go on a diet. The sisters, who said they wanted to be healthier and balance their stress levels, agreed, accepted four months of personal training and a meal delivery service paid for by the magazine, lost a combined 50 pounds and kept a journal of their experiences, which appears in the April issue. “Kate and I have decided we have to do this program in a realistic way,” Laura Mulleavy wrote in an Oct. 22 entry. “We’ll have wine when we feel like it and cheat on holidays.” Reactions to the issue have been blistering. Dozens of objections were posted to an entry about the diet on the blog Jezebel. Nonetheless, Cynthia M. Bulik, a professor of eating disorders at the University of North Carolina in Chapel Hill, defended the offer as it was presented in the magazine, noting that the designers had written that a doctor had also told them to get in shape. She said she was surprised by the controversy, given that Anna Wintour, in her editor’s letter, had challenged designers to use healthier looking models. “I saw more of an emphasis on healthy eating and healthy fitness than an order, ‘You’ve got to lose weight,’ ” Dr. Bulik said. The magazine has a track record of chronicling the diets of its staff, and in 1998, Oprah Winfrey acknowledged that she had agreed to lose 20 pounds in order to appear on its cover. Copyright 2008 The New York Times Company

Keyword: Obesity; Anorexia & Bulimia
Link ID: 11480 - Posted: 06.24.2010

By GINA KOLATA THE runner’s high: Every athlete has heard of it, most seem to believe in it and many say they have experienced it. But for years scientists have reserved judgment because no rigorous test confirmed its existence. Yes, some people reported that they felt so good when they exercised that it was as if they had taken mood-altering drugs. But was that feeling real or just a delusion? And even if it was real, what was the feeling supposed to be, and what caused it? Some who said they had experienced a runner’s high said it was uncommon. They might feel relaxed or at peace after exercising, but only occasionally did they feel euphoric. Was the calmness itself a runner’s high? Often, those who said they experienced an intense euphoria reported that it came after an endurance event. My friend Marian Westley said her runner’s high came at the end of a marathon, and it was paired with such volatile emotions that the sight of a puppy had the power to make her weep. Others said they experienced a high when pushing themselves almost to the point of collapse in a short, intense effort, such as running a five-kilometer race. Copyright 2008 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 11479 - Posted: 06.24.2010

Jim Giles Bad news for those with bulging bellies: fat that builds up around the waist during middle age may cause dementia decades later, say researchers who examined the health records of thousands of senior citizens. Scientists already know that overweight adults risk developing diabetes, heart problems and other medical conditions. But over the last few years researchers have noticed that obesity in middle age is linked with cognitive problems in the aged. Now it seems that overall body mass is not so important – it's the fat around the belly that appears to cause the problems. Epidemiologist Rachel Whitmer and colleagues looked at the medical records of 6583 adults registered with the healthcare firm she works for – Kaiser Permanente of Oakland, California. During the 1960s and 1970s, records were taken of the diameters of the adults' bellies, which gave Whitmer a rough idea of how much fat they were carrying around the waist. When she compared the measurements with the subjects' current medical records, the results were startling. Incidence of dementia increased steadily with the amount of belly fat, such that the 20% with the most belly fat were over two and half times more likely to develop dementia that those carrying the least. © Copyright Reed Business Information Ltd.

Keyword: Obesity; Alzheimers
Link ID: 11478 - Posted: 06.24.2010

Jennifer Viegas -- The feather train on male peacocks is among the most striking and beautiful physical attributes in nature, but it fails to excite, much less interest, females, according to new research. The determination throws a wrench in the long-held belief that male peacock feathers evolved in response to female mate choice. It could also indicate that certain other elaborate features in galliformes, a group that includes turkeys, chickens, grouse, quails and pheasants, as well as peacocks, are not necessarily linked to fitness and mating success. For Indian peafowl, which the researchers studied, male vocalizations appear to do a better job of grabbing the attention of females than their visually screaming "attire." "We have the idea that peacock calls most influence peahens (female peacocks)," lead author Mariko Takahashi told Discovery News. Takahashi, a researcher in the Graduate School of Arts and Sciences at the University of Tokyo, and her colleagues studied a free-ranging population of Indian peafowl at Izu Cactus Park, Shizuoka, Japan. © 2008 Discovery Communications

Keyword: Sexual Behavior
Link ID: 11477 - Posted: 06.24.2010

Heidi Ledford Crave sweets? Well, stop blaming your sweet tooth. Researchers have found that mice prefer sugary water even if they lack a gene needed to taste it. Although the mice could not taste sweets, reward centres in the brain reacted when the mice drank water spiked with sucrose, but not when they drank water mixed with a low-calorie artificial sweetener. The results, published this week in Neuron 1, suggest that mice can detect calories without relying on their taste buds — a finding that could change our understanding of the sugar cravings that can plague dieters and contribute to obesity. The presence of a calorie-sensing pathway makes evolutionary sense, says study author Ivan de Araujo, now at Yale University in New Haven, Connecticut. “The taste system evolved to allow animals to quickly detect what is worth eating versus what is not,” says de Araujo. “But the real reward that they need is not the taste itself but the calories.” Previous work has suggested that rats could also sense sugars without tasting them. Anthony Sclafani of the City University of New York and his colleagues trained rats to associate a flavour of unsweetened Kool-Aid (an artificially flavoured drink) with the infusion of either glucose or water directly into their stomachs2. If, for example, they were given grape Kool-Aid together with water, and cherry Kool-Aid together with glucose, over time the rats developed a predilection for cherry Kool-Aid when given a choice between the two. © 2008 Nature Publishing Group

Keyword: Chemical Senses (Smell & Taste); Obesity
Link ID: 11476 - Posted: 06.24.2010

Sharon Begley My favorite story about the Dalai Lama doesn’t concern his activities on behalf of Tibet, which is one unrelieved tragedy, but is about his interest in neuroscience. A few years ago the Dalai Lama was visiting an American medical school and watched a brain operation. Afterwards, he chatted with the surgeon, telling him how his scientist friends had patiently explained to him that all of our thoughts, feelings, memories, dreams and other mental activities are the products of electrical and chemical activity in the brain. But he had always wondered something, the Dalai Lama told the surgeon. If electricity and chemistry can produce thoughts and all the rest, can thoughts act back on the physical stuff of the brain to change its chemical, electrical and other physical properties? The surgeon dismissed the question with a polite but indulgent no. (The Dalai Lama's English translator, Thupten Jinpa, told me this story in 2005.) The brain produces and shapes mental activity, the brain surgeon said; mental activity does not alter the brain. That wasn’t a stupid answer 10 years ago, before scientists had fully grasped the potential of the adult brain to change in structure and function—an ability called neuroplasticity. But now researchers have documented a long list of examples of how the brain, once thought to be basically unchangeable after the ripe old age of 3, can indeed change. © 2008 Newsweek, Inc.

Keyword: Learning & Memory; Emotions
Link ID: 11475 - Posted: 06.24.2010

By Richard Black A South American river dolphin uses branches, weeds and lumps of clay to woo the opposite sex and frighten off rivals, scientists have discovered. Researchers observed adult male botos carrying these objects while surrounded by females, and thrashing them on the water surface aggressively. Writing in the journal Biology Letters, they say such behaviour has never before been seen in any marine mammal. The boto lives in only two rivers, and numbers are thought to be declining. A group of British and Brazilian researchers studied the dolphin's unique courtship behaviour over three years in the Mamiraua Reserve, a flooded rainforest area on the Amazon. "You see them coming up with bits of wood or lumps of rock in a very ritualised manner," recalled Tony Martin from the Sea Mammal Research Unit at St Andrews University. "Quite often they'd slowly come up above the surface in a vertical posture holding this stuff in their mouths, then sink down rotating on their own axis. "They would also throw it or smash it against the surface, and it does appear that the waving around and bashing is to impress the ladies; but at the same time there's a lot of aggression between adult males, and we have to infer that's part of it." Professor Martin's group established that rock carrying and branch thrashing were almost exclusively the preserve of adult males, and that they did it more when lots of adult females were present. Although the males were more aggressive towards each other at these times, they were never seen to hit each other with the rocks or plants. (C)BBC

Keyword: Sexual Behavior
Link ID: 11474 - Posted: 03.26.2008

By SANDRA BLAKESLEE Degus are highly social, intelligent rodents native to the highlands of Chile. They adorn the openings of their burrows with piles of sticks and stones, have bubbly personalities and like to play games. But in a laboratory setting, degus can do much more than play hide-and-seek, according to a study in the online journal Plos One (www.plosone.org). They can learn to use tools. Specifically, degus have been trained to reach through a fence, grab hold of a tiny rake and pull their favorite food, half a peeled sunflower seed, close enough to reach with their mouths. After two months of practice, researchers say, the degus can move the rake as smoothly and efficiently as croupiers in any Las Vegas casino. This is first time rodents have been trained to wield tools, said Atshushi Iriki, a neuroscientist, who led the experiments at the Laboratory for Symbolic Cognitive Development at the Riken Institute in Tokyo. But other species may soon join them. While it has long been thought that tool use is a hallmark of higher intelligence, Dr. Iriki said, the brain structures that underlie such abilities may lie dormant in many animals with good hand-and-eye or paw-and-eye coordination. Training them to use tools in captivity provides insights into the plasticity of their brains, he said, and may shed light on how early humans evolved tool use in the first place. Copyright 2008 The New York Times Company

Keyword: Learning & Memory
Link ID: 11473 - Posted: 03.26.2008

By LAURA BLUE Though most of us spend a lifetime pursuing happiness, new research is showing that that goal may be largely out of our control. Two new studies this month add to a growing body of evidence that factors like genes and age may impact our general well-being more than our best day-to-day attempts at joy. In one study, researchers at the University of Edinburgh suggest that genes account for about 50% of the variation in people's levels of happiness — the underlying determinant being genetically determined personality traits, like "being sociable, active, stable, hardworking and conscientious," says co-author Timothy Bates. What's more, says Bates, these happiness traits generally come as a package, so that if you have one you're likely to have them all. Bates and his Edinburgh colleagues drew their conclusions after looking at survey data of 973 pairs of adult twins. They found that, on average, a pair of identical twins shared more personality traits than a pair of non-identical twins. And when asked how happy they were, the identical twin pairs responded much more similarly than other twins, suggesting that both happiness and personality have a strong genetic component. The study, published in Psychological Science, went one step further: it suggested that personality and happiness do not merely coexist, but that in fact innate personality traits cause happiness. Twins who had similar scores in key traits — extroversion, calmness and conscientiousness, for example — had similar happiness scores; once those traits were accounted for, however, the similarity in twins' happiness scores disappeared. © 2008 Time Inc

Keyword: Emotions; Genes & Behavior
Link ID: 11472 - Posted: 06.24.2010