Howard Hughes Medical Institute researchers have identified small regions within a yeast protein that control the protein's conversion to an infectious agent known as a prion. Yeast prions are proteins that are conceptually similar to the mammalian prions that have gained notoriety for their roles in such fatal brain-destroying human diseases as Creutzfeldt-Jakob disease and kuru, and in the animal diseases, scrapie and bovine spongiform encephalopathy, or “mad cow disease.” “No one knew that prion conversion was controlled by such a small region, and in such a specific way,” said HHMI investigator Susan Lindquist at the Whitehead Institute for Biomedical Research. Lindquist and postdoctoral fellow Peter Tessier published a research article describing their findings on May 10, 2007, in the journal Nature. The precision of this process offers key insights into the mysterious behavior of prions, Lindquist observed. Different configurations of the recognition region cause the prion to assume different shapes, or variants. “We've been able to understand some fundamental questions about how prions form different strains and how they establish and overcome species barriers,” said Tessier. First isolated and purified in the early 1980s, prions are proteins that can fold into self-templating configurations, so that proteins of the same type adopt the same configuration. © 2007 Howard Hughes Medical Institute.

Keyword: Prions
Link ID: 10291 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — The audio world of dinosaurs, especially larger species like T. rex, was deep and low, according to new research on hearing in archosaurs, a group that includes birds, crocodiles, alligators and the extinct dinosaurs. The discovery reveals how similar the ear anatomical structure is among living birds, crocodilians and their distant dino relatives. The findings, which will be presented in June at the Acoustical Society of America Meeting in Utah, also suggest that dinosaurs produced noises that were similar to the sounds they could hear. "As a general rule, animals can hear the sounds that they produce," lead author Robert Dooling told Discovery News. Dooling is a professor of psychology and co-director of the Center for the Comparative and Evolutionary Biology of Hearing at the University of Maryland at College Park. He conducted the comparative study on archosaur ear data with German neuroanatomists Otto Gleich and Geoffrey Manley. In addition to gathering inner ear measurements for living animals, the team took these same measurements from fossil remains of brachiosaurus, allosaurus and archeoptryx. © 2007 Discovery Communications Inc.

Keyword: Hearing; Evolution
Link ID: 10290 - Posted: 06.24.2010

Bruce Bower Intensive meditation training does more than foster inner peace and relaxation. Mental practice of this type boosts control over attention and expands a person's ability to notice rapidly presented items, at least during a laboratory test. The new results demonstrate that mental resources devoted to attention can be amplified through mental training, say psychologist Richard J. Davidson of the University of Wisconsin–Madison and his colleagues. Davidson's team studied a phenomenon known as the attentional blink. Because visual perception requires time and effort, paying close attention to one object flashed on a computer screen often causes a person to overlook a second object presented within the next half second. Scientists suspect that attention momentarily shuts down as the first image is perceived. During that attentional blink, the second image sneaks by unnoticed. "The previous practice of meditation improves performance on this task," Davidson says. "Attention capabilities can be enhanced through learning." His team studied 17 volunteers, ages 22 to 64, who attended a 3-month-long meditation retreat. They spent most of each day practicing Vipassana meditation, which focuses on reducing mental distractions and heightening sensory awareness. ©2007 Science Service

Keyword: Attention; Emotions
Link ID: 10289 - Posted: 06.24.2010

Susan Milius In 1939, a man walking his dog in Brooklyn noticed Hollywood finches for sale in a store. The reddish-brownish seed eaters are native to the dry Southwest, including Southern California. A 1918 law was supposed to have protected such North American migratory birds from capture and sale as caged birds—though the rule was seldom enforced. The dog walker complained to authorities, and this time they began a crackdown. When some store owners around the city realized that they would get in trouble, they opened the cages and let the evidence fly away. The odds would seem to be against desert birds from the other side of the continent surviving in New York City, but the finches settled into Central Park. From there, the population spread to New Jersey, and then—watch out, world. During the next 60 years, what are now called house finches (Carpodacus mexicanus) moved into all the other lower-48 states and beyond. They now thrive in places as different climatically as Ontario and Florida. With such extreme adaptability, they're "like birds made of interchangeable plastic parts," says Alex Badyaev of the University of Arizona in Tucson. One of the differences that Badyaev has observed among the widely scattered house finches shows up in their egg laying. The order in which mothers lay eggs containing male and female embryos isn't random, he finds. ©2007 Science Service

Keyword: Sexual Behavior; Vision
Link ID: 10288 - Posted: 06.24.2010

Arran Frood Vaporizing cannabis leaves instead of burning them can release the drug's active ingredient just as effectively — while avoiding the harmful toxins inhaled through smoking the drug, according to a pilot study. The result could be good news for those who choose to use marijuana medicinally. The potential benefits of marijuana include pain relief for multiple-sclerosis sufferers, a treatment for glaucoma, as an appetite stimulant for AIDS patients and an anti-nausea agent for people on chemotherapy. But smoking isn't a good method of drug delivery because the harmful effects — such as lung cancer and heart disease — outweigh the likely merits of marijuana for all but terminal cases. Rather than smoking, some use the leaves to make tea or cakes for consumption. But this means that the active agents are metabolized by the liver rather than entering the bloodstream unaltered. Others have focused on extracting active ingredients such as tetrahydrocannabinol (THC) and delivering them alone in a pill or oral spray. However, many think that the isolated ingredients are not as effective as the whole plant, and it is more difficult to customize the dose for each individual with a pill. Donald Abrams of the University of California, San Francisco, and his team decided to investigate the benefits of the 'Volcano', a commercially available vaporizer. The device heats marijuana leaves to a temperature between 180 and 200 °C so that THC is released from oils on the surface of the leaf but no actual combustion takes place. ©2007 Nature Publishing Group

Keyword: Drug Abuse
Link ID: 10287 - Posted: 06.24.2010

By Maggie Fox, Health and Science Editor WASHINGTON (Reuters) - More than 200 proteins are affected in Huntington's disease, researchers reported on Thursday in a study that offers scientists many potential routes to finding treatments for the fatal brain disease. Tests on fruit flies show that the mutated Huntington's protein that underlies the disease interacts with 200 other proteins, the researchers report in the Public Library of Science journal PLoS Genetics. Many of these interactions damage brain cells. "It's the gene producing something that seems to interfere with the normal activities of the cell in many, many different places and ways," Dr. Eugene Oliver, who oversees some Huntington's disease work at the National Institute for Neurological Disorders and Stroke, said in a telephone interview. Dr. Juan Botas of the Baylor College of Medicine in Houston, Texas, who worked on the study, said researchers can experiment with the proteins and the genes responsible for their production. "When you tinker with some of these genes, you find that some of them improve the symptoms. These could be potential therapeutic targets," Botas said in a statement. © 1996-2007 Scientific American, Inc

Keyword: Huntingtons
Link ID: 10286 - Posted: 06.24.2010

Maria Cheng, Associated Press — If it really is what's on the inside that counts, then a lot of thin people might be in trouble. Some doctors now think that the internal fat surrounding vital organs like the heart, liver or pancreas — invisible to the naked eye — could be as dangerous as the more obvious external fat that bulges underneath the skin. "Being thin doesn't automatically mean you're not fat," said Dr. Jimmy Bell, a professor of molecular imaging at Imperial College, London. Since 1994, Bell and his team have scanned nearly 800 people with MRI machines to create "fat maps" showing where people store fat. According to the data, people who maintain their weight through diet rather than exercise are likely to have major deposits of internal fat, even if they are otherwise slim. "The whole concept of being fat needs to be redefined," said Bell, whose research is funded by Britain's Medical Research Council. Without a clear warning signal — like a rounder middle — doctors worry that thin people may be lulled into falsely assuming that because they're not overweight, they're healthy. "Just because someone is lean doesn't make them immune to diabetes or other risk factors for heart disease," said Dr. Louis Teichholz, chief of cardiology at Hackensack Hospital in New Jersey, who was not involved in Bell's research. © 2007 Discovery Communications Inc.

Keyword: Obesity
Link ID: 10285 - Posted: 06.24.2010

Roxanne Khamsi Brain structures in primates have developed due to different pressures on males and females to keep up with social or competitive demands, a new study suggests. A comparison of brains from 21 primate species, including gorillas and chimps, suggests that those with greater male-on-male competition have more brain matter devoted to aggression and coordination. Whereas those species in which there is more social mixing between males and females have evolved bigger brains with higher-level thinking. Competition for status and mates among primates might have influenced brain evolution, the researchers say. They add that contrasting brain types resulting from behavioural differences between the sexes might be a factor in other branches of mammalian brain evolution beyond anthropoid primates. In the early 1980s, a group of researchers published information about the brain anatomy of 21 different primate species – which included gorillas, chimps and rhesus monkeys, but not humans. The team took each brain and cut it into thin slices. They photographed each slice and marked the boundaries of the brain structures they saw. By measuring the areas of these marked regions, the scientists were able to reconstruct various brain structures and estimate their volume. © Copyright Reed Business Information Ltd

Keyword: Aggression; Evolution
Link ID: 10284 - Posted: 06.24.2010

Forget the “decade of the brain” (that old nineties phraseology): it’s becoming evident that we’re probably not going to get over our fascination with neuroscience anytime this century. The fact is, as a result of today’s neurobiological revolution, nothing is what it used to be. And that includes motherhood. The Hallmark Corporation doesn’t seem to have caught on to this yet, but the reasons for celebrating Mother’s Day are changing yet again. America’s holiday for mothers began as a formal acknowledgement of the fact that so many women were unselfishly dedicated to helping those in the community less fortunate than themselves. The work clubs pioneered by Ann Reeves Jarvis serve as a prime example of this kind of aspiration. (See "Mother’s Day or Mothers’ Day” by Vision’s Larry Green.) Somewhere along the line, however, the focus of Mother’s Day moved closer to the center of a mother’s sphere of influence, toward what she does within her household for her own family. While these contributions are considerable and indispensable, in some ways perhaps such an inward focus narrows our sphere and encourages us to contemplate what is “owed” us than rather than the more optimistic understanding of how much we have gained, and how much more these gains enable us, in turn, to give. Thankfully, however, neuroscientists may have uncovered just the research to distract us from obsessing about our own sacrifices long enough to consider some of the things families actually do for mothers: to be more specific, what children do for mothers. ©2007 Vision.org.

Keyword: Sexual Behavior
Link ID: 10283 - Posted: 06.24.2010

By GARDINER HARRIS, BENEDICT CAREY and JANET ROBERTS When Anya Bailey developed an eating disorder after her 12th birthday, her mother took her to a psychiatrist at the University of Minnesota who prescribed a powerful antipsychotic drug called Risperdal. Created for schizophrenia, Risperdal is not approved to treat eating disorders, but increased appetite is a common side effect and doctors may prescribe drugs as they see fit. Anya gained weight but within two years developed a crippling knot in her back. She now receives regular injections of Botox to unclench her back muscles. She often awakens crying in pain. Isabella Bailey, Anya’s mother, said she had no idea that children might be especially susceptible to Risperdal’s side effects. Nor did she know that Risperdal and similar medicines were not approved at the time to treat children, or that medical trials often cited to justify the use of such drugs had as few as eight children taking the drug by the end. Just as surprising, Ms. Bailey said, was learning that the university psychiatrist who supervised Anya’s care received more than $7,000 from 2003 to 2004 from Johnson & Johnson, Risperdal’s maker, in return for lectures about one of the company’s drugs. Doctors, including Anya Bailey’s, maintain that payments from drug companies do not influence what they prescribe for patients. Copyright 2007 The New York Times Company

Keyword: Anorexia & Bulimia; Schizophrenia
Link ID: 10282 - Posted: 06.24.2010

Boosting levels of a protein in the brain could be a way of treating diseases such as epilepsy and schizophrenia, scientists suggest. Researchers at the University of Bristol say the SUMO protein acts to damp down the amount of information transmitted to cells. Such "over-excitement" is characteristic of many conditions which affect the brain. Experts said the findings in Nature would further understanding. There are 100 million nerve cells in the brain, which each have 10,000 connections, called synapses, which link to other nerves cells. These connections chemically transmit information that control brain function via proteins called receptors. These processes are believed to be the basis of learning and memory. In a healthy brain, synapses can modify how efficiently they work, by increasing or decreasing the amount of information transmitted. Having too much information is a problem, but so is having too little which can cause conditions including coma. The researchers, who carried out work on rats, found that when one type of receptor, the kainate receptor, receives a chemical signal a small protein called SUMO attaches itself. SUMO pulls the kainate receptor out of the synapse, stopping it from receiving information from other cells and making the cell less excitable. The scientists who discovered SUMO's role say it is interesting because it means the receptor is not destroyed, but simply lies dormant, meaning the dangers of completely cutting off communication between cells should be avoided. (C)BBC

Keyword: Epilepsy
Link ID: 10281 - Posted: 05.09.2007

By STUART ELLIOTT FOR decades, the beauty industry was described as — or accused of — selling “hope in a jar.” Now, a marketing blitz with a budget estimated at more than $150 million in the first year will try to persuade dieters to seek hope in a pill bottle despite widespread skepticism about the grandiose promises of diet pills, plans and potions. A campaign for the drug Alli is being waged on many fronts by seven agencies. Its first-year budget is estimated at more than $150 million. The campaign, being introduced in stages by seven agencies, promotes a product from GlaxoSmithKline called Alli — pronounced, not coincidentally, like “ally,” as in a helper or associate. Alli is the first weight-loss drug to be approved by the Food and Drug Administration for sale in the United States over the counter, no prescription necessary. It works by preventing the body from absorbing some of the fat one eats. The campaign is centered on an elaborate Web site, myalli.com. There are also television commercials, direct mailings, print advertising, books, online ads, displays in stores and information being provided to health care professionals. Copyright 2007 The New York Times Company

Keyword: Obesity
Link ID: 10280 - Posted: 06.24.2010

By Shankar Vedantam The government's methods for deciding compensation for emotionally disturbed veterans have little basis in science, are applied unevenly and may even create disincentives for veterans to get better, an influential scientific advisory group said yesterday. The critique by the Institute of Medicine, which provides advice to the federal government on medical science issues, comes at a time of sharp increases in cases of post-traumatic stress disorder (PTSD) among veterans and skyrocketing costs for disability compensation. The study was undertaken at the request of the Department of Veterans Affairs amid fears that troops returning from the wars in Iraq and Afghanistan will produce a tidal wave of new PTSD cases. Between 1999 and 2004, benefit payments for PTSD increased nearly 150 percent, from $1.72 billion to $4.28 billion, the report noted. Compensation payments for disorders related to psychological trauma account for an outsize portion of VA's budget -- 8.7 percent of all claims, but 20.5 percent of compensation payments. VA officials said they welcomed the report. "VA is studying the findings, conclusions and recommendations of the report to determine actions that can be taken to further enhance the services we provide," spokesman Matt Burns said in a statement. © 2007 The Washington Post Company

Keyword: Stress
Link ID: 10279 - Posted: 06.24.2010

Targeting enzyme produced by a specific gene may lead to better medications The likelihood of developing bipolar disorder depends in part on the combined, small effects of variations in many different genes in the brain, none of which is powerful enough to cause the disease by itself, a new study shows. However, targeting the enzyme produced by one of these genes could lead to development of new, more effective medications. The research was conducted by scientists at the National Institutes of Health’s National Institute of Mental Health (NIMH), with others from the Universities of Heidelberg and Bonn and a number of U.S. facilities collaborating in a major project called the NIMH Genetics Initiative. The study is the first to scan virtually all of the variations in human genes to find those associated with bipolar disorder. Results were published online May 8 in Molecular Psychiatry by Amber E. Baum, PhD, lead researcher Francis J. McMahon, MD, and colleagues. “This is an example of how advances in genetics research feed into practical applications. This research would not have been possible a very few years ago. We now have a new molecular target scientists can investigate in their search for better medications for bipolar disorder,” said NIH Director Elias A. Zerhouni, MD. About 5.7 million American adults have bipolar disorder, which also is called manic-depressive illness. Symptoms include extremes in mood, from pronounced over-excitement and elation, often coupled with severe irritability, to depression. Children also may have the condition, usually in a more severe form than adults.

Keyword: Schizophrenia
Link ID: 10278 - Posted: 06.24.2010

New evidence on sex differences in people’s brains and behaviors emerges with the publication of results from the British Broadcasting Corporation’s (BBC) Sex ID Internet Survey. Survey questions and tests focused on participants’ sex-linked cognitive abilities, personality traits, interests, sexual attitudes and behavior, as well as physical traits. The Archives of Sexual Behaviorš has devoted a special section in its April 2007 issue to research papers based on the BBC data. BBC Science, in collaboration with researchers in the United Kingdom and North America, designed their research project on psychological sex differences in conjunction with their TV documentary, Secrets of the Sexes. The project culminated in the creation of the BBC Internet Survey, which was posted on the BBC Science and Nature website. In just three months (February-May 2005), over 250,000 people from all over the world responded to the full survey. Some initial results were presented in July 2005 in the program, Secrets of the Sexes. The complete dataset has been analyzed since, with key findings published in the current issue of the Archives of Sexual Behavior. The BBC summaries of the articles are available online at http://www.bbc.co.uk/science/humanbody/sex/articles/results/. 1. Archives of Sexual Behavior, Vol. 36, No. 2, April 2007

Keyword: Sexual Behavior
Link ID: 10277 - Posted: 06.24.2010

By SANDRA BLAKESLEE In meditation, people sit quietly and concentrate on their breath. As air swooshes in and out of their nostrils, they attend to each sensation. As unbidden thoughts flutter to mind, they let them go. Breathe. Let go. Breathe. Let go. According to a study published today in the online edition of the journal PloS Biology, three months of rigorous training in this kind of meditation leads to a profound shift in how the brain allocates attention. It appears that the ability to release thoughts that pop into mind frees the brain to attend to more rapidly changing things and events in the world at large, said the study’s lead author, Richard Davidson, a professor of psychology and psychiatry at the University of Wisconsin in Madison. Expert meditators, he said, are better than other people at detecting such fast-changing stimuli, like emotional facial expressions. Dr. Ron Mangun, director of the Center for Mind and Brain at the University of California, Davis, who was not involved in the study, called the finding exciting. “It provides neuroscience evidence for changes in the workings of the brain with mental training, in this case meditation,” he said. “We know we can learn and improve abilities of all sorts with practice, everything from driving to playing the piano. But demonstrating this in the context of meditation is interesting and novel.” Copyright 2007 The New York Times Company

Keyword: Attention; Emotions
Link ID: 10276 - Posted: 06.24.2010

By ANAHAD O’CONNOR Doctors have long said that an aspirin a day can help ward off heart attacks. But what about Alzheimer’s? The claim that aspirin can prevent the disease stems from the notion that Alzheimer’s is caused by inflammation that disrupts proteins in the brain. It’s believed that aspirin, and possibly other nonsteroidal anti-inflammatory drugs, may reduce or head off that process. One recent analysis of previous studies found that people who took a low dose of aspirin every day for several years reduced their risk of developing Alzheimer’s by 13 percent. Another study in 2003 in The European Journal of Clinical Pharmacology found a similarly beneficial effect for aspirin and other nonsteroidal anti-inflammatory drugs. But more recent, randomized studies have called those findings into question. One of the most prominent followed more than 6,000 older women for nearly a decade and found that those who regularly took 100 milligrams of aspirin did no better on cognitive tests, over time, than those who were given a placebo.

Keyword: Alzheimers
Link ID: 10275 - Posted: 06.24.2010

By GINA KOLATA It was 1959. Jules Hirsch, a research physician at Rockefeller University, had gotten curious about weight loss in the obese. He was about to start a simple experiment that would change forever the way scientists think about fat. Obese people, he knew, had huge fat cells, stuffed with glistening yellow fat. What happened to those cells when people lost weight, he wondered. Did they shrink or did they go away? He decided to find out. It seemed straightforward. Dr. Hirsch found eight people who had been fat since childhood or adolescence and who agreed to live at the Rockefeller University Hospital for eight months while scientists would control their diets, make them lose weight and then examine their fat cells. The study was rigorous and demanding. It began with an agonizing four weeks of a maintenance diet that assessed the subjects’ metabolism and caloric needs. Then the diet began. The only food permitted was a liquid formula providing 600 calories a day, a regimen that guaranteed they would lose weight. Finally, the subjects spent another four weeks on a diet that maintained them at their new weights, 100 pounds lower than their initial weights, on average. Copyright 2007 The New York Times Company

Keyword: Obesity; Genes & Behavior
Link ID: 10274 - Posted: 06.24.2010

A new study supports earlier estimates of the prevalence of bipolar disorder in the U.S. population, and suggests the illness may be more accurately characterized as a spectrum disorder. It also finds that many people with the illness are not receiving appropriate treatment. The study, published in the May 2007 issue of Archives of General Psychiatry, analyzed data from the National Comorbidity Survey Replication (NCS-R), a nationwide survey of mental disorders among 9,282 Americans ages 18 and older. The NCS-R was funded by the National Institutes of Health’s National Institute of Mental Health (NIMH). NIMH researcher Kathleen Merikangas, Ph.D. and colleagues identified prevalence rates of three subtypes of bipolar spectrum disorder among adults. Bipolar I is considered the classic form of the illness, in which a person experiences recurrent episodes of mania and depression. People with bipolar II experience a milder form of mania called hypomania that alternates with depressive episodes. People with bipolar disorder not otherwise specified (BD-NOS), sometimes called subthreshold bipolar disorder, have manic and depressive symptoms as well, but they do not meet strict criteria for any specific type of bipolar disorder noted in the Diagnostic and Statistical Manual for Mental Disorders (DSM-IV), the reference manual for psychiatric disorders. Nonetheless, BD-NOS still can significantly impair those who have it. The results indicate that bipolar I and bipolar II each occur in about 1 percent of the population; BD-NOS occurs in about 2.4 percent of the population.

Keyword: Schizophrenia
Link ID: 10273 - Posted: 06.24.2010

WASHINGTON, DC– In adult monkeys, an antidepressant treatment has induced new nerve cell growth in the hippocampus, a brain area responsible for learning and memory. A similar process may occur in humans, the research suggests, and may help explain the effectiveness of antidepressant treatments. The results, the first from nonhuman primates, are similar to those previously seen in rodents. They suggest that creation of new nerve cells, a process known as neurogenesis, is an important part of antidepressant therapy. Researcher Tarique Perera, MD, at Columbia University, and colleagues observed changes in the number of brain cells in the dentate gyrus region of the hippocampus. The study is published in the May 2 issue of The Journal of Neuroscience. The growth of new nerve cells in the hippocampus has been suggested as the way antidepressants work in rodents, says Eric Nestler, MD, PhD, of the University of Texas Southwestern Medical Center. "However, the clinical relevance of this action has remained controversial, in part, because of uncertainty as to whether similar neurogenesis occurs in humans," he says. "This finding further supports the potential clinical relevance of changes in neurogenesis seen in rodent models." Perera and the team treated a group of monkeys with electroconvulsive shock (ECS), an animal version of the highly effective clinical antidepressant electroconvulsive therapy. They saw an increase in new nerve cells in the hippocampus. Over four weeks, a majority of these cells became mature neurons.

Keyword: Depression; Neurogenesis
Link ID: 10272 - Posted: 06.24.2010