New Haven, Conn. -- Yale scientists have systematically plotted the responses of the entire Drosophila (fruit fly) olfactory system, providing the first multi-dimensional map of the range of odorants sensed and the regions of the brain that are stimulated. John Carlson, the Eugene Higgins Professor of Molecular, Cellular and Developmental Biology and Elissa Hallem, his former graduate student in the Interdepartmental Neuroscience Program, published the comprehensive study in the journal Cell. "The results of our analysis allow us to make predictions about which odors smell alike to an animal, and which smell different," said Carlson. "These predictions can now be tested in behavioral experiments and may help point us to insect attractants and repellants that are highly effective." This paper provides particular insight into the understanding of how animals perceive environmental smells that are often complex mixtures of molecular structures. The study identifies compounds that both stimulate and inhibit response in odor neurons, and the differences in response that are due to concentration and duration of exposure to a compound.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8777 - Posted: 04.14.2006

Comparative studies have studied testosterone levels and related them to mating systems and aggression, but very few studies have attempted to relate testosterone to fitness, that is, the combination of lifetime reproductive success and survival, in the wild or experimentally. Over nine breeding seasons, Wendy Reed (North Dakota State University) and her colleagues followed a group of dark-eyed juncos, small mountain songbirds found throughout North America. They injected males with elevated levels of testosterone and found that they had shorter lives but that they were very successful at siring more offspring – even with females who were mated with other males. "The surprising result was that testosterone-treated males had a higher overall fitness than control males," write the authors in a study in the May issue of American Naturalist. This led to the question of why don't juncos naturally have higher levels of testosterone? Testosterone-treated males produced more offspring, but they were smaller, and smaller offspring had lower postfledging survival. Older, more experienced females preferred to mate with older males and realized higher reproductive success when they did so. While young males treated with testosterone increased their ability to attract older females, it resulted in poor reproductive performance.

Keyword: Sexual Behavior
Link ID: 8776 - Posted: 06.24.2010

With swelling prison populations, researchers are trying to understand the biology behind aggressive behavior. National Institute of Mental Health scientist Andreas Meyer-Lindenberg is looking for clues to how genes wire our brains early in life. He's focusing on a specific gene that was previously linked to impulsive violence in certain populations of people. A study in 2002 found that subjects with a particular form of a gene had a significantly higher risk of violence only if they were abused as children. While this gene-environment interaction is important in understanding this behavior, Meyer-Lindenberg wanted to focus on the genetic facets of violence. The study also found that a variation in this gene, called MAOAG, disproportionately affects men, because this gene is located on the X chromosome, which determines sex. Since men only have one X chromosome, they are more prone to the effects of the gene. Women have two X chromosomes, but the chances of having the gene variation on both chromosomes is very rare. "One of the most fascinating things," Meyer-Lindenberg says, about this field of science called psychiatric genetics, "is how it is possible that genes [can] encode for molecules that affect something as complex as behavior, even psychiatric illness such as depression and social behavior." © ScienCentral, 2000-2006.

Keyword: Aggression; Genes & Behavior
Link ID: 8775 - Posted: 06.24.2010

When 8 year-old Andrew Kilbarger of Lancaster, Ohio received three injections in his right arm, he became one of six boys participating in the first U.S. gene therapy trial for muscular dystrophy. Andrew has Duchenne Muscular Dystrophy (DMD). DMD patients lack the gene that controls production of a protein called dystrophin, which helps keep muscle cells intact. Patients with DMD usually die by the age of 25, often because of the failure of the heart and breathing muscles. The start of any new gene therapy trial is an exciting time. But for the Muscular Dystrophy Association (which funded the trial), and the participants and doctors involved at Columbus Children's Hospital, this is a particularly exciting event because for this disease, it has been a long, hard road. Researchers discovered the gene for dystrophin 20 years ago but since it is one of the largest genes known, it was too big to work with. In 2000, geneticist Xiao Xiao found a way to miniaturize the gene. His team at the University of Pittsburgh tested the "mini-dystrophin" gene in a strain of mice with muscular dystrophy. The improvement seen in the muscle tissue of the mice was dramatic, and led to the human trial that just began. "The limitation of that is the gene vehicle will not be widespread. It will… be localized around the injection site. However, diseases like muscular dystrophy affect almost every skeletal muscle cell," he says." So you cannot, in theory, inject the genes into every muscle cell directly. So we have to figure out a novel or innovative way to deliver or disseminate [the gene]." © ScienCentral, 2000-2006.

Keyword: Muscles
Link ID: 8774 - Posted: 06.24.2010

Everyone is familiar with the sinking feeling you get after deleting a computer file by mistake or leaving the house without your keys. But such events also cause their own unique reactions in the brain. US scientists writing in the Journal of Neuroscience found one area becomes more active after "costly" mistakes. They say it may help explain obsessive compulsive disorder, where minor events appear to be enough to triger an over-reaction in the same area. In the study, the brains of 12 healthy adults were examined using a functional MRI (fMRI) scanner while they were undertook 360 computer tests, such as spotting the odd one out or picking pairs of letters. Succeeding at some carried a small financial reward, while failing at others incurred penalties. Others carried no reward or penalty. People were told they had a $10 (£5.70) "credit" to begin, and that they would receive real cash depending on their balance at the end. The response to a mistake that cost them money was seen to be greater than the response to other mistakes and involved a part of the brain called the rostral anterior cingulate cortex (rACC). That part of the brain did not show the same level of activity when the mistake did not carry a penalty, or had a neutral consequence. The researchers had already found in previous research that the rACC area did become more active when there was no cost in people with OCD. (C)BBC

Keyword: OCD - Obsessive Compulsive Disorder
Link ID: 8773 - Posted: 04.14.2006

Roxanne Khamsi The first common genetic variant that substantially increases a person’s risk of obesity has been identified, researchers claim. They hope that their discovery will open doors to new treatments for the condition. The team identified a small genetic change in a region of DNA near a gene known as INSIG2 as being linked to obesity. DNA code is made up of four bases, or "letters". A single change in this particular region, from a G to a C, makes a person more prone to obesity, according to the study. They believe this change somehow affects the regulation of the gene INSIG2, which has a role in fat production. The US researchers, led by Albert Herbert at the Boston University Medical School, found that an individual with two copies of the C variant is 22% more likely to have a body mass index (BMI) greater than 30 – the point where people move from being "overweight" to "obese". This is the first study to strongly identify a genetic component in obesity in a number of populations, comments Carol Shoulders at Imperial College London, UK. © Copyright Reed Business Information Ltd

Keyword: Obesity; Genes & Behavior
Link ID: 8772 - Posted: 06.24.2010

By Shankar Vedantam Pharmaceutical giant Eli Lilly and Co. recently funded five studies that compared its antipsychotic drug Zyprexa with Risperdal, a competing drug made by Janssen. All five showed Zyprexa was superior in treating schizophrenia. But when Janssen sponsored its own studies comparing the two drugs, Risperdal came out ahead in three out of four. In fact, when psychiatrist John Davis analyzed every publicly available trial funded by the pharmaceutical industry pitting five new antipsychotic drugs against one another, nine in 10 showed that the best drug was the one made by the company funding the study. "On the basis of these contrasting findings in head-to-head trials, it appears that whichever company sponsors the trial produces the better antipsychotic drug," Davis and others wrote in the American Journal of Psychiatry. Such studies make up the bulk of the evidence that American doctors rely on to prescribe $10 billion worth of antipsychotic medications each year. Davis pointed out the potential biases in design and interpretation that produced such contradictory results. Other experts note that industry studies invariably seek to boost the image of expensive drugs that are still under patent. Moreover, they say, the trials are relatively brief and test drugs on patients with simpler problems than doctors typically encounter in daily practice. © 2006 The Washington Post Company

Keyword: Schizophrenia
Link ID: 8771 - Posted: 06.24.2010

DURHAM, N.H. -- In a former cowshed on the edge of the University of New Hampshire campus, David Berlinsky, assistant professor of zoology, peers into a big blue plastic tub. Inside, black sea bass circle slowly in the dim light. The converted barn is now an aquaculture research facility for the College of Life Sciences and Agriculture, and home to Berlinsky’s latest research. Black sea bass feature prominently on many menus, but wild populations of the fish are in decline and their availability is limited. Because of the high demand, they’re a good candidate for aquaculture on the east coast. Except, that is, for one problem: they have a tendency to change sex unpredictably in captivity. “In the wild, black sea bass are born as females and turn into males at around two to five years old,” Berlinsky explains. “When you bring them into captivity, they change into males more quickly.” Some captive-born fish emerge as males even before reaching adulthood, devoting energy toward reproductive development and away from growth. Such problems make breeding and growing the fish in captivity a tricky proposition. “Black sea bass is a wonderful fish to culture and to eat,” says George Nardi, vice president and director of GreatBay Aquaculture, a commercial fish farm in Newington, NH. But the sex change problem must be tackled if fish farmers are to bring a high-quality fish to market. “We invest in our brood stocks, the parents of the young fish, much as a thoroughbred horse farm invests in mares and stallions,” he says. “It doesn’t do us much good if we always have to go out and get new females.”

Keyword: Sexual Behavior
Link ID: 8770 - Posted: 06.24.2010

Boston, MA – Researchers from the Harvard School of Public Health, Kaiser Permanente, and a team of collaborators have found further evidence implicating the Epstein-Barr virus (EBV) as a possible contributory cause to multiple sclerosis (MS). The study appears in the advance online edition of the June 2006 issue of Archives of Neurology. MS is a chronic degenerative disease of the central nervous system. Women are more likely than men to get the disease and it is the most common neurologically disabling disease in young adults. Although genetic predisposition plays an important role in determining susceptibility, past studies have shown that environmental factors are equally important. EBV is a herpes virus and one of the most common human viruses worldwide. Infection in early childhood is common and usually asymptomatic. Late age at infection, however, often causes infectious mononucleosis. In the U.S., upwards of 95% of adults are infected with the virus, but free of symptoms. EBV has been associated with some types of cancer and can cause serious complications when the immune system is suppressed, for example, in transplant recipients. There is no effective treatment for EBV. The study population was made up of more than 100,000 members of the Kaiser Permanente Northern California (KPNC) health plan, who provided blood specimens as part of medical examinations between 1965 and 1974.

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 8769 - Posted: 06.24.2010

Adam Keiper Every so often, when some new scientific paper is published or new experiment revealed, the press pronounces the creation of the first bionic man—part human, part machine. Science fiction, they say, has become scientific reality; the age of cyborgs is finally here. Many of these stories are gross exaggerations. But something more is also afoot: There is legitimate scientific interest in the possibility of connecting brains and computers—from producing robotic limbs controlled directly by brain activity to altering memory and mood with implanted electrodes to the far-out prospect of becoming immortal by “uploading” our minds into machines. This area of inquiry has seen remarkable advances in recent years, many of them aimed at helping the severely disabled to replace lost functions. Yet public understanding of this research is shaped by sensationalistic and misleading coverage in the press; it is colored by decades of fantastical science fiction portrayals; and it is distorted by the utopian hopes of a small but vocal band of enthusiasts who desire to eliminate the boundaries between brains and machines as part of a larger “transhumanist” project. It is also an area of inquiry with a scientific past that reaches further back in history than we usually remember. To see the future of neuroelectronics, it makes sense to reconsider how the modern scientific understanding of the mind emerged.

Keyword: Robotics; Parkinsons
Link ID: 8768 - Posted: 06.24.2010

ANN ARBOR, Mich. -- It happens to all of us, no matter how hard we try. Whether it's deleting a computer file and realizing a split-second later that we can't get it back, or dropping a bag of groceries, or realizing that our gas tank is nearly empty on a lonely stretch of highway, we all make mistakes that aren't just annoying, but potentially costly. Now, a team of University of Michigan researchers has looked inside the human brain and captured the instant when someone makes a costly mistake. What they've found is interesting by itself, but may also help scientists understand mental health problems such as obsessive-compulsive disorder, or OCD. In general, the U-M scientists found that a particular part of the brain called the rostral anterior cingulate cortex, or rACC, becomes much more active when a person realizes he or she has made an error that carries consequences – for instance, losing money. By contrast, the same area of the brain doesn't show the same level of activity when the mistake doesn't carry a penalty, or even when a correct action carries a reward. The rACC is thought to be involved with emotional responses, and scientists had suspected it might also be involved in response to costly errors. But this is the first brain-imaging study to test that idea.

Keyword: Emotions; Brain imaging
Link ID: 8767 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Labradors and dachshunds appear to waddle, while greyhounds seem to march by with a fast clip, but new research has determined that the basic mechanics behind dog walking are the same for all canines. The discovery could lead to a better understanding of health issues related to walking in dogs, such as hip problems. It could also result in improvements to four-legged, dog-like robots, which the U.S. military already is investigating. "The big benefit would be to show how robot dogs should walk more efficiently," said lead scientist Jim Usherwood, a researcher at the University of London's Royal Veterinary College Structure and Motion Laboratory. Usherwood added, "Almost all robots require a large amount of power — much higher than an animal would use — partly because they tend to use bent legs. I show what would happen with stiff legs." Inspired by stiff-legged mechanical toys that can walk down hills, Usherwood and his team designed several different computer models for dog walking. The researchers then compared these models with observations of actual dogs on a treadmill. © 2006 Discovery Communications Inc.

Keyword: Miscellaneous
Link ID: 8766 - Posted: 06.24.2010

Prashant Nair A strategy to reverse some of the brain changes triggered by cocaine, which lead to addiction, may have been uncovered by Swiss scientists. The findings constitute the first step in the development of a drug to reverse cocaine-driven rewiring in the brain, the researchers claim. Cocaine triggers changes in the brain that lead to the development of drug sensitisation – a learning-associated process that underlies addiction. Like many addictive drugs, cocaine ups the concentration of the brain chemical dopamine, causing neurons that respond to dopamine to fire. This process reorganises the brain circuitry and hardwires the addiction by disrupting the normal connections between two different brain regions. Those areas are the hippocampus and prefrontal cortex – associated with learning and memory – and the ventral tegmental area, involved with feelings of pleasure, reward and behavioural motivation (see "Cocaine use prevents adaptive behaviour"). But how cocaine drives this change in dopamine neurons was unclear until recently. Now, Christian Luescher and Camilla Bellone at the University of Geneva, Switzerland have shown that cocaine causes a switch in the components, or subunits, which make up the receptors on the surface of neurons in the ventral tegmental area, the brain’s "pleasure centre". This leads to excitatory wiring – or strong stimulation of these cells. Brain slices from mice given cocaine, showed the receptors in their brains had undergone a subunit switch. © Copyright Reed Business Information Ltd

Keyword: Drug Abuse
Link ID: 8765 - Posted: 06.24.2010

Snoring may run in families, a study by US scientists says. Researchers at Cincinnati Children's Hospital found children whose parents snore have a three-fold increased risk of being noisy sleepers themselves. But UK experts said the link was likely to be related to families being obese - half of snoring is related to weight. The study, based on interviews with 681 families and published in the Chest journal, also suggested a link between snoring and allergies. Researchers found children who tested positive for atopy, an earlier indicator for the development of asthma and allergies, were twice as likely to snore as those who did not. Parents were questioned about the extent to which both they and their children snored. Habitual snoring was reported in 15% of the children, and allergy sensitivity in 29%. Among the parents, 20% of mothers and 46% of fathers were habitual snorers. An increased risk of snoring occurred in 21.5% of children who were sensitive to allergy triggers compared with 13% of those who were not prone to allergies. The same trend was seen in 21.8% of children with a parental history of habitual snoring. Only 7.7% of children without a snoring parent turned out to be frequent snorers. The researchers said it was likely allergy-related respiratory diseases were causing the snoring. (C)BBC

Keyword: Sleep; Genes & Behavior
Link ID: 8764 - Posted: 04.11.2006

By JANE E. BRODY Americans' use of sleeping pills is skyrocketing, up nearly 60 percent since 2000, with about 42 million prescriptions filled last year. Experts surmise that "modern lifestyles" and the accompanying stress of too much to do in too little time are largely responsible for the growing need for the drugs. That may be true. But I see an altogether different explanation for the flagrant use of sleeping pills. In the last decade, there has been a sea change in the kinds of drugs available to induce sleep, and these drugs have been widely promoted in print and on television. You could hardly have missed that pale green luna moth (sans antennas) drifting over peaceful sleepers in ads for Lunesta, which has joined Ambien, Sonata and others in a new class of sleep aid. How tempting it is when people hear that, say, five milligrams of Ambien can temporarily sweep their worries under the mattress, allow them to fall asleep within 15 minutes and awaken the next morning refreshed and raring to go. I took it myself for several months last winter when the painful aftermath of knee replacements rendered a restful night's sleep impossible. Unfortunately, with the ease of writing and filling a prescription and the mostly good press these new drugs have gotten to date, millions of people are now taking them without first exploring the reasons for their sleep problems and possible nondrug routes to cure them. Copyright 2006 The New York Times Company

Keyword: Sleep
Link ID: 8763 - Posted: 04.11.2006

There is probably not a person alive on this planet who is immune to anxiety. As a psychiatrist, I'm often accustomed to thinking of anxiety as a symptom of a disorder like social phobia or major depression or as an aspect of normal everyday mental life. As unpleasant as anxiety can be, it is unlikely to represent a major threat, let alone kill someone — at least that's what I thought until I met my patient Mark. A 42-year-old man with a long history of anxiety and depression, Mark had made a remarkable recovery with medication and psychotherapy. Long after he'd been in remission from his depression, he came to see me about some financial problem that was upsetting him. Sure, he looked a bit anxious and troubled, but he was facing a real hardship, so a little anxiety seemed a perfectly reasonable, if not healthy, response to an unpleasant situation. But something about his appearance bothered me. He seemed ever so slightly short of breath and restless in his seat, something I'd never seen even in the throes of his worst anxious depressions. Copyright 2006 The New York Times Company

Keyword: Emotions
Link ID: 8762 - Posted: 06.24.2010

SAN DIEGO, — Cognitive impairment in people with AIDS exists in two forms -- one mild, another severe -- each affecting different areas of the brain, according to the results of a University of Pittsburgh School of Medicine study being presented today at the American Academy of Neurology 58th Annual Meeting in San Diego, Calif. The researchers say their findings indicate there probably are two separate mechanisms that can cause cognitive impairment in people with AIDS. “The advent of combination antiretroviral therapies to treat AIDS has significantly changed the course of the disease,” said James T. Becker, Ph.D., professor of psychiatry, neurology and psychology at the University of Pittsburgh. “Not only are people living longer with AIDS, but we are finding that a number of the other co-existing conditions that people with AIDS often experience are becoming less severe. Such is the case with cognitive impairment – we are finding less people have severe cases while more have milder forms.” Cognitive impairment in people with AIDS is caused when the HIV virus attacks the brain and can be a complicated syndrome resulting in deficits in mood, behavior, motor coordination and thought processes. Studies have shown that, especially since the advent of the first combination antiretroviral therapies, the incidence of severe dementia in people with AIDS has decreased significantly. However, AIDS-related dementia isn’t disappearing, and a greater number of people are living with a milder form of cognitive impairment.

Keyword: Miscellaneous
Link ID: 8761 - Posted: 06.24.2010

New Haven, Conn. -- Based on data obtained from one of the largest family sets of its kind, Yale School of Medicine researchers have identified a genetic linkage for dependence on drugs such as heroin, morphine and oxycontin. The lead author, Joel Gelernter, M.D., professor in the Department of Psychiatry, said the researchers recruited a sample of 393 small families, most with at least two individuals with opioid dependence. They then searched genetic signposts throughout the entire genome in an effort to identify markers that, within the same family, would show that individuals who share the illness also share marker alleles, or gene variants. This information allowed the team to identify where genes influencing opioid dependence are located. Gelernter said the researchers found evidence of gene linkage for opioid dependence. They also found strong evidence of linkage in the family groups for the symptom cluster traits characterized by dependence on substances other than opioids, specifically, alcohol, cocaine and tobacco. "These results provide a first basis to identify genes for opioid dependence from a genome-wide investigation," Gelernter said. "Research in the laboratory now is focused on finding specific genes that modify risk for opioid dependence."

Keyword: Drug Abuse; Genes & Behavior
Link ID: 8760 - Posted: 04.11.2006

Roxanne Khamsi The stimulating drugs known as amphetamines have a stronger effect on men than women, a new study reveals. The study is the first to reveal how the release of dopamine, an important nerve signalling chemical, differs between the sexes in humans, says Gary Wand of the Johns Hopkins University School of Medicine in Baltimore, Maryland, US. He says the findings could help researchers understand why some disorders such as Parkinson's disease and Tourette's syndrome more commonly afflict men than women. Research suggests that men are more prone to certain types of drug addictions. And according to a recent US health survey, 6.0% of males above the age of 12 illegally used amphetamines, also known as 'uppers', while only 3.8% of females did so. The new work showed amphetamines caused a greater surge of the pleasure-causing chemical dopamine in men than in women. "The fact that they responded differently to the drug suggests that there's an underlying biological sex difference in how the brain's reward centre responds to amphetamines," says Wand. The team recruited 43 healthy volunteers between the ages of 18 and 29 years of whom about a third were women. The participants did not have a history of drug abuse. The volunteers were given relatively low doses of amphetamines, and their dopamine response was measured with the help of a second chemical. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Sexual Behavior
Link ID: 8759 - Posted: 06.24.2010

Jacqueline Ruttimann People who have had near-death experiences are more likely to mix up dreams and reality than those who have not, researchers say. At times of extreme danger or trauma, many people report out-of-body experiences, seeing intense lights, or a feeling of peace. "Near-death experiences are more common than people realize," says neurophysiologist Kevin Nelson of the University of Kentucky, Lexington, lead author of the study published in Neurology1. Some studies have shown that electrical stimulation to the brain can trigger aspects of near-death experiences (see 'Electrodes trigger out-of-body experience'). Drugs can do the same: ketamine, a horse tranquilizer and illegal recreational drug, can cause many of these symptoms. But spontaneous near-death experiences remain unexplained. Nelson began investigating the phenomenon after reading of near-death experiences in which patients' arms and legs were paralysed. He knew that some people experience similar paralysis just before sleeping or just after waking. "A light bulb went on in my head," he says. Near death experiences are more common than people realize. ©2006 Nature Publishing Group

Keyword: Sleep
Link ID: 8758 - Posted: 06.24.2010