BUFFALO, N.Y. -- Researchers at the University at Buffalo and the University of Pennsylvania were the first to demonstrate that two intracellular events, both stimulated by the same cell receptor, can provoke different behaviors in mammals. The broad implication of the findings may alter the way behavioral neuroscientists think about sub-cellular underpinnings of mammalian behavior, according to the researchers. The study, "Divergent Behavioral Roles of Angiotensin Receptor Intracellular Signaling Cascades," was published in the journal Endocrinology (Vol. 146, No. 12). It can be found online at http://endo.endojournals.org/cgi/content/full/146/12/5552. The co-authors of the study are Derek Daniels, assistant professor of psychology at the University at Buffalo, and Daniel K. Yee, research associate professor, Department of Animal Biology, University of Pennsylvania School of Veterinary Medicine. Daniels says, "The research highlights the importance of intracellular events in the regulation of behavioral states and provides new information about the means through which a single hormone can influence multiple mammalian behaviors like learning and memory, eating, drinking, reproduction and social interaction." © 2006 University at Buffalo.

Keyword: Hormones & Behavior
Link ID: 8690 - Posted: 06.24.2010

A two-year-old can quickly link an object--whether a flashy rattle or a boring latch--to a word. Even a one-year-old can follow a parent's gaze to an object and match it with a word being spoken. But although anecdotal evidence seems to show that babies younger than one year can learn words, it remains unclear whether they are in fact mastering language. Now a new study reveals that 10-month-old infants can link words and objects, but only if the object is already interesting to them. Psychologist Kathy Hirsh-Pasek of Temple University and her colleagues tested 44 infants for the ability to learn words. The infants averaged an understanding of nearly 14 words already, according to their mothers. But the researchers paired four novel objects--a blue sparkle wand and a white cabinet latch, a pink party clacker and a beige bottle opener--with four nonsensical words--modi, glorp, dawnoo and blicket--to test their ability to associate new words with new objects. Sitting on their mothers' laps, the infants were exposed to the objects. First, they were allowed to play with an interesting and boring object pair followed by seeing the two objects placed on a rotating board. This was done to assess which object was more interesting to the babies and, as expected, they preferred the brightly-colored, noisy ones. Then the researchers placed the two objects on a table in front of the infant. If the baby was in one group, the experiment leader pointed to the interesting object and labeled it with one of the nonsense words. If the baby was a member of the other group, the researcher pointed to the boring object and labeled it with the same nonsense word. Regardless of the researchers’ efforts, the infants looked at the object they found interesting. © 1996-2006 Scientific American, Inc.

Keyword: Language; Development of the Brain
Link ID: 8689 - Posted: 06.24.2010

In a series of experiments designed help scientists understand the brain chemicals that guide mate selection, Pfaff and his colleagues exposed female mice to odors of either a male mouse alone or a male mouse with a female. The females consistently preferred the scent of males linked to other females. "Our data suggest that female mice may use, or even copy, the interests of other females based on olfactory cues," says Pfaff, who is head of the Laboratory of Neurobiology and Behavior. "It could also be seen as a female trusting the mate choice of another female." That one female's choice of mate could influence the choices of other females is well documented in birds and fish, but had not been documented for any mammalian species. Pfaff says that the female mice's mate preference was so strong that they even preferred the combined male/female scent when it was tainted with the scent of infectious parasites, opting for that over the scent of a healthy lone male. "Male odors can provide female mice with information on their quality, condition, health and suitability as a potential mate," says Pfaff. "This type of 'public information' uses cues inadvertently provided by an individual, such as odor, which others observe use to make decisions such as mate choice, food location, or presence of danger. Specifically in birds and fish, 'public information' has been shown play a role in when and what to eat and with whom to mate with, but its use in mate choice has not been seen in mammals."

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 8688 - Posted: 03.22.2006

—Penn State researchers have created an elegantly simple model of an axon--the extension of a neuron that communicates with other neurons--and have used this model to reproduce a change in the axon's shape that is characteristic of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. This achievement is the first of its kind in a highly simplified biophysical model system. The model provides a novel avenue for investigating the specific mechanisms that contribute to complex brain diseases. It also provides a means of discovering new kinds of drugs for the treatment of these disorders. The research will be described in a paper to be published in the 4 April 2006 issue of the Proceedings of the National Academy of Science. This model, produced in the laboratory of Paul S. Weiss, Distinguished Professor of Chemistry and Physics at Penn State, has the essential features of an axon, including a lipid membrane that encloses a "cytoskeleton" scaffolding, which produces the axon's shape. The outer membrane was prepared to contain a very small amount of dye molecules that are sensitive to ultraviolet light. Shining light on the artificial axons initiated a photochemical reaction that produced highly reactive "free radicals" and triggered a catastrophic oxidative-stress reaction. The result was that the previously protruding microtubule cytoskeleton collapsed into a constricted and deformed structure resembling a string of beads--the same morphology observed during the degeneration of actual neurons. Surprisingly, the model reproduced this highly characteristic "beading" or "pearling" even though it does not include proteins that were previously thought to be essential for causing this kind of axon destruction.

Keyword: Parkinsons; Alzheimers
Link ID: 8687 - Posted: 06.24.2010

By Ingrid Wickelgren The next time you drive in the fog, check your speedometer. You may be speeding and not know it. That's because--when the visual landscape lacks contrast--people perceive objects moving much slower than they actually are. A new study debuts the first convincing, quantitative explanation for this potentially dangerous visual mistake. In 1982, psychologist Peter Thompson of York University, United Kingdom, first noticed that when two objects of different contrast are moving at the same speed, people always say the higher contrast object is moving faster. Researchers brushed off this misperception, dubbed "the Thompson effect," as a kink in an otherwise precisely tuned visual machine. But a few years ago, Eero Simoncelli, a computational neuroscientist at New York University in New York City, and his colleagues wondered if they could explain this phenomenon using basic principles of human vision. Simoncelli knew that the eye does not simply record light patterns like a camera does: Instead, what people see depends greatly on past experience (a cloud looks like a boat to one person and a truck to another, for example). So he and colleagues suspected that, when real information is sketchy (as it is in low-contrast situations), people rely even more heavily on their expectations. In a 2002 paper, the researchers used Bayesian statistics--a branch of mathematics that shows the ideal way to combine expectations with new information--to prove that this was indeed the case. It could also account for the Thompson effect, they argued. © 2006 American Association for the Advancement of Science

Keyword: Vision
Link ID: 8686 - Posted: 06.24.2010

Two risk factors that place males at greater risk for heart disease than women appear to be influenced by genes on the X chromosome, report researchers at the NIH and the University of Texas Southwestern Medical School. The finding appears in a Research Letter in the Journal of the American Medical Association. In a separate Research Letter, the researchers at the NIH and at Thomas Jefferson University in Philadelphia also report that women who lack functioning ovaries — either because of a hereditary condition or due to an illness — are more likely than are other women to experience shyness and anxiety in social situations. In the first report, researchers studied women with Turner syndrome, a hereditary condition in which women are missing all or part of one X chromosome, explained the senior author of both reports, Carolyn Bondy, Chief of the Developmental Endocrinology Branch at NIH’s National Institute of Child Health and Human Development. The researchers tested whether the women had inherited their single normal X chromosome from their mothers or from their fathers. Women normally inherit one of their two X chromosomes from their mother and one from their father. Men normally inherit a single X chromosome from their mothers. The researchers also measured the women’s body fat distribution patterns and their cholesterol and triglyceride levels. Dr. Bondy explained that men have a greater tendency than do women to accumulate fat within their abdomens, while women tend to accumulate fat around their hips, buttocks, and thighs. Proportionally higher abdominal fat distribution is associated with cholesterol levels that increase the chances of cardiovascular disease.

Keyword: Genes & Behavior; Obesity
Link ID: 8685 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — A Scotsman with a heavy brogue may speak the same language as a Texas cowboy, but each has a distinct accent; now researchers have discovered that female whipbirds in Australia sing the same basic songs, but with regional accents. Female birds in general rarely sing, so that find itself is unusual. The determination is doubly noteworthy because the scientists observed that the males of this species, Psophodes olivaceus, sing with no accent whatsoever. "It is so intriguing to see both of these opposite patterns occurring within the same species," said lead researcher Daniel Mennill, a professor of behavioral ecology at the University of Windsor in Canada. "You wouldn't be shocked to visit one town and hear people speak with a twang, and then visit another town and hear a drawl ... .," he said. "But can you imagine if, in your travels, you found that females sounded different in each town, but males had the same brogue? These whipbirds demonstrate such a pattern." Mennill and his colleague Amy Rogers measured eastern whipbird recordings from 16 different populations along the east coast of Australia. For each of the 112 birds that they recorded, they measured the song's number of syllables, the length of the first syllable, the highest and lowest frequency of the last syllable, the time between these frequency extremes and other characteristics. © 2006 Discovery Communications Inc.

Keyword: Language
Link ID: 8684 - Posted: 06.24.2010

Children with personalities marked by aggressiveness, mood swings, a sense of alienation and a need for excitement may be at greater risk for attention deficit hyperactivity disorder or conduct disorder, according to a new Florida State University study. FSU psychology professors Jeanette Taylor and Chris Schatschneider, FSU doctoral student Kelly Cukrowicz and University of Minnesota Professor William Iacono found that children with ADHD or conduct disorder had more negative emotions - aggressiveness, tension and feelings of being exploited, unlucky or poorly treated - and lower constraints - a tendency to break rules and engage in thrill-seeking behavior - than children with neither of the disorders. Not surprisingly, those children who have both ADHD and conduct disorder had the most extreme personality profiles. "This helps us to understand that personality is part of the bigger picture of these disorders," Taylor said. "That could help with initial assessments or lead to unexpected discoveries or potential interventions. We're saying to researchers and clinicians, 'Think about personality when you look at these issues.' " The study, published in the Journal of Child Psychology and Psychiatry, is the first to investigate personality trait patterns among children who have ADHD, conduct disorder or a combination of both. It is important to learn more about the co-occurrence of ADHD and conduct disorder because the consequences are so severe, Taylor said.

Keyword: ADHD; Aggression
Link ID: 8683 - Posted: 03.22.2006

ANN ARBOR, Mich.—It was once thought that only humans gestured to direct another person’s attention, but such “referential” gesturing was recently observed in wild chimpanzees. John Mitani, University of Michigan anthropology professor, and colleague Simone Pika, a postdoctoral fellow in psychology at University of St. Andrews in Scotland, observed male chimps habitually using “directed scratches” to request grooming of specific areas on the body. The findings suggest that our closest living relatives may be capable of mental-state attribution, making inferences about the knowledge of others. Up until now, scientists saw directed scratching only in captive chimps and language-trained apes who interacted with humans, Mitani said. “The more we learn, the more we see chimpanzees employing remarkable, seemingly human-like behaviors,” Mitani said. “To me that is one of the lessons of this little paper.” The findings appear in today’s issue of Current Biology, in a paper entitled “Referential Gestural Communication in Wild Chimpanzees.” Copyright © 2005 The Regents of the University of Michigan

Keyword: Evolution
Link ID: 8682 - Posted: 06.24.2010

The songs of the humpback whale are among the most complex in the animal kingdom. Researchers have now mathematically confirmed that whales have their own syntax that uses sound units to build phrases that can be combined to form songs that last for hours. Until now, only humans have demonstrated the ability to use such a hierarchical structure of communication. The research, published online in the March 2006 issue of the Journal of the Acoustical Society of America, offers a new approach to studying animal communication, although the authors do not claim that humpback whale songs meet the linguistic rigor necessary for a true language. With limited sight and sense of smell in water, marine mammals are more dependent on sound—which travels four times faster in water than air—to communicate. For six months each year, all male humpback whales in a population sing the same song during mating season. Thought to attract females, the song evolves over time. Suzuki and co-authors John Buck and Peter Tyack applied the tools of information theory—a mathematical study of data encoding and transmission—to analyze the complex patterns of moans, cries, and chirps in the whales' songs for clues to the information being conveyed. Buck is an electrical engineer who specializes in signal processing and underwater acoustics at the University of Massachusetts Dartmouth, and Tyack is a biologist at Woods Hole Oceanographic Institution in Massachusetts. © 2006 Howard Hughes Medical Institute

Keyword: Hearing; Language
Link ID: 8681 - Posted: 06.24.2010

A 24-year-old Norfolk woman hopes to be among the first British patients to overcome a severe stammer by using a special electronic device. Heidi King is volunteering for the treatment in New York, the British Stammering Association (BSA) said. BSA chief executive Norbert Lieckfeldt said the device, like a hi-tech hearing aid, would be fitted in her inner ear. It then mimics the user's voice after research showed stammerers are helped by speaking in unison with others. Test revealed singing or saying the same words together - the so-called "choral effect" - can help people stop stammering. The phenomenon was first identified in the 1950s and the earpiece would convert the way Heidi, from Norwich, hears her own voice into a chorus-like sound. The device, called SpeechEasy, is not available in the UK and is not funded by the National Health Service. On Monday Miss King said she needed to raise about £5,000 to cover the costs of her treatment and the three weeks she would need to stay in New York. (C)BBC

Keyword: Language
Link ID: 8680 - Posted: 03.21.2006

The image of a twitchy nervous liar touching his nose and stroking his hair may itself be a lie, a study says. Italian and British researchers found when people lied they tended to stay still as they were acutely aware their body language might give them away. The team monitored 130 volunteers as they were asked to make a series of honest and dishonest statements. The study, in Journal of Nonverbal Behaviour, found liars touched their noses 20% less than truth tellers. Psychologist Dr Samantha Mann, who co-authored the study, said there was a popular perception that when people lie they scratch their nose and play with their hair more. These movements are known as self-adaptor gestures which serve to comfort a person feeling vulnerable or exposed. Instead of giving into these urges, she claimed, liars tried very hard to stay still and were just as likely as an honest person to look the questioner in the eye. She added: "People expect liars to be nervous and shifty and to fidget more, but our research shows that is not the case. "People who are lying have to think harder, and when we think harder we tend to be a lot stiller, with fewer movements, because we are concentrating harder." She added: "As soon as we know that we are lying we suddenly become very aware of our behaviour. Most people tend to refrain from making movements at all." The team from the universities of Portsmouth and Bergamo in Italy, also looked for changes in seven categories of hand gestures in their volunteers. They found liars literally went to huge lengths to cover their tracks, especially when they were challenged over whether they were telling the truth. Those under strong suspicion used certain types of hand gestures more in order reinforce the point. (C)BBC

Keyword: Stress
Link ID: 8679 - Posted: 03.21.2006

By Sandra G. Boodman The pocket-watch-sized device is billed as "a pacemaker for the brain," the newest cutting-edge treatment for as many as 4 million adults whose severe depression is not relieved by psychotherapy, drugs or even shock treatments. Since its approval under unusual circumstances eight months ago by the Food and Drug Administration (FDA), more than 550 Americans have undergone surgery to have a vagus nerve stimulator (VNS) implanted in their chests to activate parts of their brains. Another 7,000 people -- aided by a network of nurses hired by Cyberonics, the Houston-based manufacturer of the device -- are seeking approval from their insurance companies for the $25,000 operation. More than 3,700 psychiatrists, including doctors affiliated with Suburban, Georgetown, Sheppard Pratt and Howard University hospitals, have been trained in the use of VNS, the first device ever approved to treat depression. It consists of a battery-operated generator attached to an electrode implanted in the vagus nerve in the neck. The generator emits regular pulses of electricity that are supposed to stimulate serotonin and other brain chemicals believed to regulate mood, according to Cyberonics. Yet despite the imprimatur of the FDA and an aggressive marketing campaign mounted by the company, the most basic question about the treatment remains unanswered: Does it work? Is VNS a lifesaving treatment for chronic depression, as some patients and doctors maintain, or an unproven and potentially harmful treatment based on flimsy science, as critics contend? © 2006 The Washington Post Company

Keyword: Depression
Link ID: 8678 - Posted: 06.24.2010

By Matt McMillen From the start of their marriage, Jeremy Gaylord had a habit of walking away from his wife, Nancy, while she was in mid-sentence. That annoyed her. But when he also did it to people at parties, she took action. "I'd slam my foot down on his to keep him from drifting off," she recalled, laughing, in a recent phone interview from the couple's home in Bridgewater, Vt. Nancy thought he was just plain rude. Five years ago, she learned there was another possible explanation: attention-deficit hyperactivity disorder, or ADHD. When Jeremy's attention wandered, he did, too. Just about everyone occasionally zones out, procrastinates or speaks and acts without thinking. But for those with ADHD -- including many who don't know they have the disorder -- such experiences are more frequent, intense and disruptive, said Tom Brown, assistant clinical professor of psychiatry at Yale University and author of "Attention Deficit Disorder in Children and Adults" (Yale University Press, 2005). All of which can be hard on a relationship -- especially a committed one. It's not that people with ADHD don't inspire love or affection. "There are likable, lovable sides to ADHD, " said Brown. People with the disorder are often "spontaneous, funny as hell, and bring a fresh view on things to a relationship." It's just that their admirers generally have to balance these traits with a few exasperating ones. © 2006 The Washington Post Company

Keyword: ADHD
Link ID: 8677 - Posted: 06.24.2010

By BENEDICT CAREY The only responsible way to manage schizophrenia, most psychiatrists have long insisted, is to treat its symptoms when they first surface with antipsychotic drugs, which help dissolve hallucinations and quiet imaginary voices. Benedict Carey will answer reader questions about this article. E-mail your questions to askscience@nytimes.com. His answers will be posted at nytimes.com/science on Friday. Delaying treatment, some researchers say, may damage the brain. But a report appearing next month in one of the field's premier journals suggests that when some people first develop psychosis they can function without medication — or with far less than is typically prescribed — as well as they can with the drugs. And the long-term advantage of treating first psychotic episodes with antipsychotics, the report found, was not clear. The analysis, based on a review of six studies carried out from 1959 to 2003, exposes deep divisions in the field that are rarely discussed in public. In the last two decades, psychiatrists have been treating people with antipsychotic drugs earlier and more aggressively than ever before, even testing the medications to prevent psychosis in high-risk adolescents. Copyright 2006 The New York Times Company

Keyword: Schizophrenia
Link ID: 8676 - Posted: 06.24.2010

By Constance Holden Only about two-thirds of depressed people feel better from taking antidepressant medication. Currently, doctors have no way of knowing who is likely to benefit from what drug. But now researchers have identified a gene variant that appears to enhance the odds of benefiting from antidepressants known as selective serotonin reuptake inhibitors (SSRIs). It's "a step on the road to true personalized medicine," says co-author Dennis Charney, psychiatrist at Mount Sinai Medical Center in New York City. The findings could also help explain why blacks appear to respond less than whites to antidepressants, says the lead author, psychiatrist Francis McMahon of the National Institute of Mental Health in Bethesda, Maryland. The beneficial gene variant--for a type of serotonin receptor--is far more common in whites than in blacks. McMahon and colleagues analyzed DNA samples from 1953 patients diagnosed with major depression who were being treated with the SSRI citalopram (Celexa). The patients were part of the largest-ever clinical trial for depression, called STAR*D. To scout out genes that might be associated with treatment response, they looked at 768 markers on 68 candidate genes. SSRIs act on the neurons that send out serotonin, a neurotransmitter that affects many things including mood and circadian rhythms. These antidepressants, which often have fewer side effects than others, prevent transmitting preventing neurons from soaking up unused serotonin, thus giving the serotonin neurotransmitter more time in the synapse to exert an effect. SSRIs also indirectly down-regulate the 2A receptor on postsynaptic (receiving) neurons, which is also necessary for the drugs to work. © 2006 American Association for the Advancement of Science

Keyword: Depression; Genes & Behavior
Link ID: 8675 - Posted: 06.24.2010

Work reported this week provides new evidence that marsupials, like primates, have functional color vision based on three different types of color photoreceptor cones--but unlike primates, a component of marsupial color vision includes sensitivity to ultraviolet wavelengths. In the study, researchers employed behavioral tests to show that at least one type of marsupial uses its detection of UV light as part of its ability to discriminate between colors. The new work is reported by a group including Dr. Catherine Arrese of the University of Western Australia and appears in the March 21st issue of Current Biology. The most prevalent system of color vision in mammals is known as dichromacy, which is a color-detection system based on two types of cone photoreceptors--those sensitive to short (SWS) and medium-to-long (M/LWS) wavelengths. Trichromacy, which is used by humans, was thought to be unique to primates that have re-evolved a third cone type from the duplication of the MWS/LWS gene, which enables the discrimination of green-red colors. But the researchers' previous physiological studies in Australian marsupials provided original evidence for the potential of trichromatic color vision in mammals other than primates. The findings were consistent in several distantly related marsupial species, indicating that the presence of three spectrally distinct cone types, sensitive to short (SWS), medium (MWS), and long (LWS) wavelengths, is a common feature of Australian marsupials. However, since evidence of color vision cannot be derived from physiological studies alone, marsupial trichromacy remained to be established with an unequivocal behavioural approach.

Keyword: Vision
Link ID: 8674 - Posted: 03.21.2006

A research team at Uppsala University, Sweden has shown in a new study, published in the journal Acta Zoologica, that the size of the spot on a male collared flycatcher's forehead reflects how well the immune defence system combats viruses such as avian influenza. The white spot is also attractive to female birds searching for a mate. Evolutionary biologists have long attempted to explain why individuals of a species differ in appearance and why the choice of a mate is influenced by behaviour and appearance features that cannot reasonably be thought to have any usefulness. Therefore, they have begun to look more and more at the genetics behind what are called secondary sexual characters, such as the tail of a peacock, the stripes of the female gulf pipefish, and the white spot on the forehead of the collared flycatcher. In many species both males and females prefer to mate with those who have the largest or most colourful of these ornaments or who have the most complex song, for instance. One theory says that the ornaments are clearest on individuals that are in good health and that both the size and the condition of the ornament are heritable. This leads to the question of why evolution did not select the same appearance and good health for all individuals. Is there something in the environment that is constantly changing and can govern the genetics of appearance and health, leading, instead, to diversity?

Keyword: Sexual Behavior; Evolution
Link ID: 8673 - Posted: 03.21.2006

By Jennifer Viegas, Discovery News — Diving beetles engage in such exhausting, uncomfortable sex that these insects have actually evolved two different types of females, as well as unusual variations among males, according to a new study. The find adds to the growing body of evidence that sexual conflict between males and females influences evolution. In many cases, individuals over time develop characteristics that are appealing to the opposite sex. For diving beetles, however, researchers believe females have tried to avoid the painful sex for so long that some have actually evolved a feature that enables them to spurn most suitors. The result is that the insect family Dytiscidae includes species, such as the diving beetles Dytiscus lapponicus and Graphoderus zonatus verrucifer, which each have two distinct types of females. D. lapponicus has females with smooth and furrowed backs, while G.z. verrucifer has females with smooth and granulated backs. The furrows and granulation allow these types to avoid frequent sex with males, which grab onto the females with suction-cupped feet. Findings are published in the current issue of The American Naturalist. © 2006 Discovery Communications Inc.

Keyword: Sexual Behavior; Evolution
Link ID: 8672 - Posted: 06.24.2010

A version of a gene previously linked to impulsive violence appears to weaken brain circuits that regulate impulses, emotional memory and thinking in humans, researchers at the National Institutes of Health's (NIH) National Institute of Mental Health (NIMH) have found. Brain scans revealed that people with this version – especially males – tended to have relatively smaller emotion-related brain structures, a hyperactive alarm center and under-active impulse control circuitry. The study identifies neural mechanisms by which this gene likely contributes to risk for violent and impulsive behavior through effects on the developing brain. NIMH intramural researchers Andreas Meyer-Lindenberg, M.D., Daniel Weinberger, M.D., Ph.D., and colleagues report on their magnetic resonance imaging (MRI) study online in the Proceedings of the National Academy of Sciences during the week of March 20, 2006. "These new findings illustrate the breathtaking power of 'imaging genomics' to study the brain's workings in a way that helps us to understand the circuitry underlying diversity in human temperament," said NIH Director Elias A. Zerhouni, M.D., who conducted MRI studies earlier in his career. "By itself, this gene is likely to contribute only a small amount of risk in interaction with other genetic and psychosocial influences; it won't make people violent," explained Meyer-Lindenberg. "But by studying its effects in a large sample of normal people, we were able to see how this gene variant biases the brain toward impulsive, aggressive behavior."

Keyword: Aggression; Genes & Behavior
Link ID: 8671 - Posted: 06.24.2010