By Katherine Unger The striking yodel of a male loon is no veiled threat. Loosely translated, the song means "you come here, and I'll pull all your feathers out," says biologist Charles Walcott of Cornell University in Ithaca, New York. Now, Walcott and colleagues have discovered that loons come up with fresh yodels when they move to new lakes, likely to make them stand out from the crowd. Earlier studies suggested that loons develop a distinctive yodel at a young age and stick with it. If that were true, Walcott and colleagues reasoned, they might be able to spot individual birds by their yodel. To test the idea, Walcott's team studied two populations of loons--one in Wisconsin and another in Michigan--that had already been banded, so the birds' identities could be confirmed. Male loons changed their calls only slightly from year to year, the researchers reported online 15 February in Animal Behaviour. But when the males relocated from one lake to another, as 10% to 15% do each year, Walcott's group heard something different. Comparing calls from 13 males recorded before and after a territory switch, researchers found that 12 males changed their songs significantly. "It came as a shock," says Walcott. "At first I didn't believe a word of it." © 2006 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Animal Communication
Link ID: 8576 - Posted: 06.24.2010

A National Institutes of Health-sponsored clinical trial with 200 Parkinson's disease patients has shown that creatine and minocycline may warrant further consideration for study in a large trial, according to Karl Kieburtz, M.D., M.P.H., University of Rochester, who spoke today at the World Parkinson Congress on behalf of the trial investigators. Study investigators caution that while the news is encouraging, the results do not demonstrate that these agents are effective in Parkinson's disease. Before these interventions can be recommended as a treatment they must be tested in a larger trial with hundreds of patients. Study findings are available online and will be published in the March 14 issue of Neurology.* Parkinson's disease is a degenerative disorder of the brain in which patients may develop progressive tremor, slowness of movements, and stiffness of muscles. It affects approximately 1 percent of Americans over the age of 65. Although certain drugs, such as levodopa, can reduce the symptoms of Parkinson's, no treatment has been shown to slow the progressive deterioration in function. The National Institute of Neurological Disorders and Stroke (NINDS) of the National Institutes of Health (NIH) has organized a nationwide multi-center effort called NET-PD (Neuroprotection Exploratory Trials in Parkinson's Disease), a randomized, double-blind futility trial, to study compounds that may slow the clinical decline of Parkinson's disease. As the initial step in these efforts, creatine and the antibiotic minocycline were identified as agents worthy of preliminary study. Patients very early in the disease course who did not yet need medications typically used to treat their Parkinson's symptoms were included in the study.

Keyword: Parkinsons
Link ID: 8575 - Posted: 06.24.2010

MADISON - Recent research on the genetics of smoking has focused on genes that are thought to be related to nicotine metabolism, personality traits, and regulation of emotions. According to a genetic study just published in "Nicotine and Tobacco Research," genes responsible for taste also may yield important information about who smokes and why they smoke. Researchers from the University of Wisconsin-Madison and University of Utah wanted to determine if a "bitterness" gene-phenylthiocarbamide (PTC)-was related to smoking status and how important the taste of cigarettes is to a smoker. As predicted, those smokers who possessed less sensitivity to bitter taste were more likely to rate taste as a strong reason for smoking, and those who were sensitive to bitter taste were less likely to smoke for taste. A surprising result, which must be replicated for scientific accuracy, was the discovery that smokers with a different, less common genetic variant for taste were the least likely to smoke. "Nicotine dependence is likely to be the result of many genes and complex environmental effects," said Dale Cannon with the University of Utah, lead author of the study. "What this study tells us is that genetic factors involving the taste of cigarettes should be examined as part of the analysis of nicotine dependence."

Keyword: Drug Abuse; Chemical Senses (Smell & Taste)
Link ID: 8574 - Posted: 02.24.2006

Researchers at Yale School of Medicine have found evidence that a hormone produced in the stomach directly stimulates the higher brain functions of spatial learning and memory development, and further suggests that we may learn best on an empty stomach. Published in the February 19 online issue of Nature Neuroscience by investigators at Yale and other institutes, the study showed that the hormone ghrelin, produced in the stomach and previously associated with growth hormone release and appetite, has a direct, rapid and powerful influence on the hippocampus, a higher brain region critical for learning and memory. The team, led by Tamas L. Horvath, chair and associate professor of the Section of Comparative Medicine at Yale School of Medicine, and associate professor in the Department of Obstetrics, Gynecology & Reproductive Sciences, and Neurobiology, first observed that peripheral ghrelin can enter the hippocampus and bind to local neurons promoting alterations in connections between nerve cells in mice and rats. Further study of behavior in the animals showed that these changes in brain circuitry are linked to enhanced learning and memory performance. Because ghrelin is highest in the circulation during the day and when the stomach is empty, these results also indicate that learning may be most effective before meal-time.

Keyword: Learning & Memory; Obesity
Link ID: 8573 - Posted: 02.23.2006

Researchers led by Wolfgang Sadee, a scientist at the Ohio State University, have figured out how differences in one gene can make the brain more sensitive to alcohol, narcotics, or nicotine. The gene Sadee's team looked at has long been known to code for a kind of brain protein called an opioid receptor, which acts like a switch, turning on pleasure and blocking pain when triggered by certain addictive drugs. The surfaces of our brain cells are covered by different kinds of receptor proteins. These receptors act as chemical docking stations that allow individual brain cells to communicate with each other by sending and receiving small bursts of chemicals. Each type of receptor can only be activated by a certain class of chemicals, which makes the communication between brain cells specific and meaningful. However receptors can also respond to chemicals in the brain environment not sent by other cells, like things that we've ingested such as alcohol or particles from cigarette smoke. The mu-opioid receptor that Sadee's team looked at is the primary target for morphine, but it also plays a large part in responses to alcohol, nicotine, and narcotics such as cocaine. As reported in the Journal of Biological Chemistry, Sadee and his colleagues looked at two variations, A118G and G118 of the mu-opioid receptor gene. "We've taken a variation in this gene that's already suspected to affect the response to therapy of addiction, as well as addiction itself. But we didn't know how and why," he explains. © ScienCentral, 2000-2006.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 8572 - Posted: 06.24.2010

There is little doubt that alcohol-related disorders in humans are genetically based. The influence of environmental factors, however, remains unclear. Given that studies of humans are complicated by a multitude of cultural and day-to-day-living factors, researchers in the March issue of Alcoholism: Clinical & Experimental Research use rhesus monkeys to examine genetic and environmental influences on alcohol consumption. Results indicate that, just as with humans, both genetic and environmental factors contribute to variation in alcohol consumption among the non-human primates. "Rhesus macaques provide a good model for many human diseases due in part to their phylogenetic closeness," said Joseph G. Lorenz, research associate at the Coriell Institute for Medical Research and corresponding author for the study. "Also, like humans, they are highly social, which is important for diseases like alcoholism where there are social factors affecting alcohol consumption. And, finally, because we can control their social environment and precisely measure their exposure to alcohol, whereas human studies often rely on self-reported consumption patterns."

Keyword: Drug Abuse; Genes & Behavior
Link ID: 8571 - Posted: 02.23.2006

Michael Hopkin Advances in the science of radiocarbon dating - a common, but oft-maligned palaeontological tool - have narrowed down the overlap between Europe's earliest modern humans and the Neanderthals that preceded them. Refinements to the technique, which estimates an artefact's age by sampling the amount of radioactive carbon left over from when it was formed, suggest that Homo sapiens wrested Europe from its prehistoric counterpart even quicker than had been thought. Previous estimates suggested that at least 7,000 years elapsed between H. sapiens arriving in eastern Europe more than 40,000 years ago, and the disappearance of the last known Neanderthals (H. neanderthalensis) from western France. But newly calculated dates shrink the overlap to 5,000 years. Radiocarbon dating, also known as carbon dating, is a reliable method for dating artefacts back to around 23,000 years ago. But for items older than this it has tended to underestimate ages by up to several thousand years. Carbon dating is based on the rate of decay of radioactive carbon-14 atoms found in living matter such as bones. Because carbon-14 decays to a non-radioactive form over time, older samples give off less radiation. ©2006 Nature Publishing Group

Keyword: Evolution
Link ID: 8570 - Posted: 06.24.2010

LOVERS know only too well that men usually need a "recovery period" after orgasm, and that sexual intercourse with orgasm is more satisfying than an orgasm from masturbation alone. Now scientists think the two phenomena might be linked. Following orgasm, the hormone prolactin is released into the bloodstream in both men and women. The hormone makes us feel satiated by countering the effect of dopamine, which is released during sexual arousal. Stuart Brody of the University of Paisley, UK, and Tillmann Krüger of the Swiss Federal Institute of Technology in Zurich, measured blood prolactin levels in male and female volunteers who watched erotic films before engaging in masturbation or sexual intercourse to orgasm in the laboratory.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8569 - Posted: 02.23.2006

By Rob Stein, Washington Post Staff Writer Medicare endorsed three types of stomach-shrinking surgery yesterday, saying the controversial procedures can offer Americans safe and effective ways to treat obesity. The announcement was seen as a boost for the popular operations, known as bariatric surgery, which had come under a cloud in recent years because of concerns about their safety. "In the right hands, bariatric surgery can benefit patients," said Steve Phurrough of the Centers for Medicare and Medicaid Services, which sets policy for the federal health program. Under the new rules, Medicare will pay for the surgery for obese patients who are suffering from other health problems related to their weight, as long as they undergo the procedure at centers that have been certified as well qualified by the American College of Surgeons or the American Society of Bariatric Surgery. Although some insurers do not cover it, the number of people undergoing the procedures, which cost $25,000 to $40,000, has increased rapidly, jumping from about 16,000 operations in 1992 to an estimated 170,000 in 2005. © 2006 The Washington Post Company

Keyword: Obesity
Link ID: 8568 - Posted: 06.24.2010

By JANE E. BRODY Pregnancy has long been assumed to be a time of expectant joy, at least for women whose pregnancies are planned and who look forward to motherhood. And indeed, it is a happy time for most. But not all. A significant minority — 10 to 20 percent, depending on who is counting — suffer moderate to severe depression during pregnancy, which translates to 80,000 women a year in the United States. All too often the problem goes unrecognized by the women and their doctors. Some depression symptoms — fatigue, change in appetite and lack of energy — overlap normal signs of pregnancy, prompting some women to ignore them. Others are embarrassed to mention their depressed feelings to their doctors since they're supposed to be thrilled to be pregnant. But even when pregnancy-related depression is recognized and acknowledged, women and their doctors can find themselves in a dilemma. After decades of warnings to avoid all manner of drugs, alcohol, nicotine and caffeine, pregnant women are often reluctant to take antidepressants even if their doctors will prescribe them. New studies examining possible effects of antidepressants on the fetus as well as the risks involved in failing to treat depression during pregnancy are likely to make decisions even harder. The decision to treat or not to treat must involve a careful assessment of known risks and benefits based on the best medical information available. Copyright 2006 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 8567 - Posted: 06.24.2010

Roger Highfield The reputation that elephants never forget has been given a chilling new twist by experts who believe that a generation of pachyderms may be taking revenge on humans for the breakdown of elephant society. The New Scientist reports that elephants appear to be attacking human settlements as vengeance for years of abuse by people. In Uganda, for example, elephant numbers have never been lower or food more plentiful, yet there are reports of the creatures blocking roads and trampling through villages, apparently without cause or motivation. Scientists suspect that poaching during the 1970s and 1980s marked many of the animals with the effects of stress, perhaps caused by being orphaned or witnessing the death of family members - and produced the equivalent of post- traumatic stress disorder. Many herds lost their matriarch and had to make do with inexperienced "teenage mothers." Combined with a lack of older bulls, this appears to have created a generation of "teenage delinquent" elephants. © 2005 The Standard, Sing Tao Media Corporation.

Keyword: Evolution
Link ID: 8566 - Posted: 06.24.2010

By Rhitu Chatterjee ST. LOUIS, MISSOURI--Gorillas deserve to join the club of "cultured apes." That's the conclusion of the first large-scale study of multiple behaviors in zoo gorillas, reported here yesterday at the annual meeting of the American Association for the Advancement of Science (which publishes ScienceNOW). Culture is defined as a range of behaviors learned from others that varies with the group one belongs to. For example, chimpanzees belonging to one population in Mahale, Tanzania, groom each other with one hand while clasping their free hands together. Another group in the same region has a slightly different tradition: grooming partners touch their free wrists. Yet despite growing evidence for culture in chimpanzees, bonobos, and orangutans, not much is known about gorilla culture or whether it exists at all. The elusive nature of most gorilla species makes it difficult to gather behavioral data in the wild. So a team led by primatologist and conservationist Tara Stoinski of Zoo Atlanta in Georgia decided to monitor the behavior of captive gorillas in 17 American zoos. Earlier observations by her group had shown that gorillas could copy their group members. When one gorilla used sticks to pry apart electric wires around trees to get at the bark, for example, others in the group followed suit. But in order for this behavior to be considered culture, other populations of gorillas would need to react differently. © 2006 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 8565 - Posted: 06.24.2010

As the prism of our senses, the human brain has ways of refracting sensory input in defiance of reality. This is seen, for example, in the placebo effect, when simple sugar pills or inert salves taken by unwitting subjects are seen to ease pain or have some other beneficial physiological effect. How the brain processes this faked input and prompts the body to respond is largely a mystery of neuroscience. Now, however, scientists have begun to peel back some of the neurological secrets of this remarkable phenomenon and show how the brain can be rewired in anticipation of sensory input to respond in prescribed ways. Writing in the current issue (March 1, 2006) of the journal Brain, Behavior, and Immunity, a team of University of Wisconsin-Madison scientists reports the results of experiments that portray the brain in action as it is duped. The new work, conducted by a team led by UW-Madison assistant professor of psychology and psychiatry Jack B. Nitschke, tested the ability of the human brain to mitigate foul taste through a ruse of anticipation. The work, conducted at the UW-Madison Waisman Center using state-of-the-art brain imaging techniques and distasteful concoctions of quinine on a cohort of college students, reveals in detail how the brain responds to a manipulation intended to mitigate an unpleasant experience.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8564 - Posted: 02.22.2006

By Jennifer Viegas, Discovery News — Professional dancers are born with at least two special genes that give them a leg up on the rest of us, according to a new study. Recent research also has suggested that intelligence, athletic ability and musical talent are linked to our genes and brain hard-wiring. With dancing added to the list, the evidence indicates that certain individuals are born with a predisposition to specific behaviors and talents, and that at least some of these qualities may represent evolved attributes. "I think that dancing is an evolved trait," said Richard Ebstein, who led the recent study, published in a recent Public Library of Science Genetics journal. "Animals have courtship dances and I think that human dancing represents the further development of a very ancient animal trait." Ebstein, a psychology professor at Hebrew University's Scheinfeld Center for Genetic Studies, said, "Also the fact that dancing is universal and existed in all human societies, even those communities of man separated geographically by tens of thousands of years (native Australians, native Americans, Africans, Eurasians) attests to the very early origin of dance in our evolution as a species." © 2006 Discovery Communications Inc.

Keyword: Genes & Behavior; Sexual Behavior
Link ID: 8563 - Posted: 06.24.2010

Independent research teams from Harvard Medical School and Children's Hospital Boston have identified a master protein that sheds light on one of neurobiology's biggest mysteries--how neurons change as a result of individual experiences. The research, which appears in two papers in the latest issue of Science (Feb 17), identifies a central protein that regulates the growth and pruning of neurons throughout life in response to environmental stimuli. This protein, and the molecular pathway it guides, could help investigators understand the process of learning and memory, as well as lead to new therapies for diseases in which synapses either fail to form or run rampant, such as autism, neurodegenerative diseases, and psychiatric disorders. Though axons and dendrites can be easily spotted waxing and waning under the microscope, the molecular middlemen working inside the cell to shape the neuron's sinewy processes have been much more elusive. The teams found a protein that works in the nucleus of neurons that either pares down or promotes synapses depending on whether or not the neuron is being activated. The protein, myocyte enhancer factor 2 (MEF2), turns on and off genes that control dendritic remodeling. In addition, one of the teams has identified how MEF2 switches from one program to the other, that is, from dendrite-promoting to dendrite-pruning, and the researchers have identified some of MEF2's targets.

Keyword: Learning & Memory
Link ID: 8562 - Posted: 02.22.2006

The discovery of a new role for a sex gene could explain why men are one-and-a-half times more likely to develop Parkinson's disease than women. Scientists at the University of California at Los Angeles (UCLA), US, found that a sex gene responsible for making embryos male and forming testes is also produced by the brain region targeted by the debilitating neurological disease. "Our findings may offer new clues to how the disorder affects men and women differently, and shed light on why men are more susceptible to the disease,” says Eric Vilain, a geneticist at UCLA's David Geffen School of Medicine. In 1990, UK researchers identified the male gender gene, known as SRY. It is located on the male Y sex chromosome and manufactures a protein that is secreted by cells in the testes. The UCLA study unexpectedly showed that the SRY protein also appears to help neurons located in an area of the brain known as the substantia nigra - a motor control centre - secrete the neurochemical dopamine. © Copyright Reed Business Information Ltd.

Keyword: Parkinsons; Sexual Behavior
Link ID: 8561 - Posted: 06.24.2010

Researchers from The University of Texas at Austin studying electric fish have gained new insight into how memory is stored at the level of neurons. Their finding, published in the Feb. 16 issue of Neuron, could help researchers better understand memory formation and neural disorders like epilepsy in humans. Dr. Harold Zakon, Dr. Jörg Oestreich and colleagues show that when electric fish zap each other in dark waters, their neurons store a memory of the sizzling communiqué by turning on special cell membrane channels. The channels give the fish neurons the ability to retain a memory long after its original stimulus is gone. "There is short-term stimulation that results in long-term changes in excitability," says Zakon, professor of neurobiology. "Essentially, it is memory." The electric fish studied by Zakon and Oestreich discharge electrical signals to survey their environment and communicate with each other. "Every time they discharge, it's kind of like they are opening their eyes and closing them," says Zakon. "Each pulse of electricity is a snapshot of the environment. These guys are swimming around and discharging at a very regular frequency. They're digitizing their environment."

Keyword: Pain & Touch; Learning & Memory
Link ID: 8560 - Posted: 06.24.2010

Sean Mackey, associate Director for the Pain Management Division of Stanford University School of Medicine, found that if people could watch a certain part of their brains in action in real time, they could use that feedback to learn how to manage pain. He calls it a case of, "Brain over pain." "What's unique about this specific experiment," says Mackey, "is that this experiment, for the first time, studied a group of people and taught them to learn how to control their own brain, a specific region in their own brain. And by doing so, it changed their behavior… that's never been done before." The specific part of the brain that is involved in pain perception and regulation is deep inside the brain. It's called the Rostral Anterior Cingulate Cortex (rACC). It was that part Mackey and his team wanted people to watch. People were put in an MRI scanner similar to those used to scan parts of the body for injuries. However this was a functional real-time MRI scanner, which allowed people, according to Mackey, "To then see their own brain activity on a moment by moment basis." Some of the people Mackey observed were patients who suffered chronic pain. Others were volunteers who agreed to endure a moderately painful hot probe touching them. While the volunteers were watching their own brains in action, the team then gave them various strategies on how to manage the pain. © ScienCentral, 2000-2006.

Keyword: Pain & Touch
Link ID: 8559 - Posted: 06.24.2010

By Mary Beckman ST. LOUIS, MISSOURI--Scientists hoping to find a simple set of genes that dictates a predisposition to addiction are likely to be frustrated, according to new research, which reinforces the notion that not only are addictions genetically complex, but they also overlap with each other to some extent. Studies with twins indicate that addiction to nicotine, alcohol, and other drugs is partly inherited. Health professionals would love to understand the genes responsible, but the handful identified so far likely represent only a small portion of those at work. To see if a general set of addiction genes can explain most bad habits, geneticist Kirk Wilhelmsen of the University of North Carolina, Chapel Hill, examined how smoking and other addictive behaviors were passed down in two different populations of people. The first included almost 400 California families in which at least three people smoked. People who scored highest on a standard nicotine addiction test or who had high numbers of smoking withdrawal symptoms sported a particular genetic sequence on chromosome 6, the researchers reported here today at the annual meeting for the American Association for the Advancement of Science (which publishes ScienceNOW). In contrast, those for whom cigarettes were particularly relaxing shared sequences on chromosome 15. This group also had a unique region on chromosome 4 that appears to be linked to the amount of time people take in the morning to light up. This same region is known to harbor many genes involved in alcohol metabolism. © 2006 American Association for the Advancement of Science.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 8558 - Posted: 06.24.2010

Bruce Bower Among elderly people, a spouse's hospitalization for certain ailments substantially raises his or her partner's likelihood of dying, according to the largest study ever to quantify such effects. The risk is especially great within the first month after the spouse enters the hospital. Partners died most frequently following their spouses' hospitalizations for particularly disabling conditions, such as dementia, psychiatric illness, and hip or other bone fractures, say medical sociologist Nicholas A. Christakis of Harvard Medical School in Boston and sociologist Paul D. Allison of the University of Pennsylvania in Philadelphia. "Our study shows that your chances of dying increase not just when your partner dies, but when your partner becomes seriously ill," Christakis says. After climbing rapidly in the first weeks after a spouse's hospitalization, a partner's risk of death declines to slightly above normal for a few months before rising again for the rest of the time examined, the scientists report in the Feb. 16 New England Journal of Medicine. The length of the spouse's hospitalization didn't affect the death risk. Copyright ©2006 Science Service.

Keyword: Stress; Neuroimmunology
Link ID: 8557 - Posted: 06.24.2010