Scientists have created "autistic" mice by deleting a single gene in key parts of the brain. US researchers found the mice had traits such as poor social interaction and high sensitivity. They say the findings, published in the Neuron, could point the way to better understanding of the causes of autism. One UK expert said the findings were interesting, but needed much more work before they could be applied to humans. An autistic spectrum disorder is a developmental disability that affects the way a person communicates and interacts with those around them. Such disorders tend to emerge in childhood, and affect about 90 in 10,000 people. Boys tend to be affected more often than girls. The University of Texas team looked at mice where the Pten gene - which has already been linked to other brain disorders - was deleted in the mature nerve cells in the cerebral cortex and hippocampus areas of the brain. These regions are associated with higher brain function such as learning and memory. The mice behaved in a number of socially abnormal ways, compared to another group of mice from the same litter. The genetically altered mice were socially less skilled, being far less likely to be curious about new animals coming into the cage. They also showed the same level of interest in an empty cage and in one containing another mouse - mirroring the behaviour of children with autistic spectrum disorders. (C)BBC

Keyword: Autism
Link ID: 8878 - Posted: 05.04.2006

Male tropical túngara frogs have evolved masses on their vocal cords that help them woo females with complex calls, show scientists working at the Smithsonian Tropical Research Institute (STRI) in Panama. Dr. Mike Ryan, Clark Hubbs Regents Professor of integrative biology at The University of Texas at Austin, Dr. Marcos Gridi-Papp, a post-doctoral scholar in physiological sciences at UCLA, and the late Dr. Stan Rand, of STRI, published their findings in the May 4 issue of Nature. Males of the túngara frog, Physalaemus pustulosus, attract females by singing out "whine chuck chuck" calls in wetlands and puddles during the rainy season. The males may only produce whines, but females are more attracted to males that also produce chucks. The scientists surgically removed the fibrous masses in the males' larynx and found that they could no longer produce the "chuck". The frogs produced a normal whine and attempted to add chucks to it, but the sounds that they added lacked the distinctive pattern of the chuck. "By removing the structure within the larynx, we eliminated the ability of a frog to produce a complex call," says Ryan. "Now we know that there is a structure associated with a single syllable of the call."

Keyword: Language; Evolution
Link ID: 8877 - Posted: 05.04.2006

By Kelli Whitlock Burton Give a mouse more room and a few toys, and good things happen. New neurons sprout in the hippocampus, while spatial memory improves and anxiety eases. As tempting as it might be to tie the new neurons to the behavioral changes, a new study finds no link between them. The results contradict a popular assumption among scientists that new neurons in the hippocampus contribute to the cognitive boost that comes with a more stimulating environment. The notion that two parts of the brain--the hippocampus and olfactory bulb--continue to produce new neurons into adulthood has been widely accepted since the late 1990s. But just what role those new cells play in cognitive function remains a mystery. Recent studies have found that animals housed in larger cages with opportunities for exercise and social interaction generate more new neurons in the hippocampus than do animals in more cramped quarters with no playmates. Scientists in the lab of Columbia University neurobiologist René Hen hoped to find the link between hippocampal neurogenesis and certain behaviors such as learning and memory that involve the hippocampus. Hen's team zapped mice with a focused dose of radiation to halt neurogenesis in a portion of the animals' hippocampuses. They then placed half the animals in regular cages and half in enhanced environments for 6 weeks before testing their anxiety and spatial memory. To the researchers' surprise, the animals with better accommodations had improved spatial memory skills and were less anxious than mice in smaller confines, despite not having any new neurons in their hippocampuses. © 2006 American Association for the Advancement of Science.

Keyword: Learning & Memory; Neurogenesis
Link ID: 8876 - Posted: 06.24.2010

The prospect of a paycheck, good grade, or promotion wonderfully concentrates the mind, and researchers have now identified the brain circuitry responsible for such reward-motivated learning. In an article in the May 4, 2006, Neuron, Alison Adcock and colleagues report brain-scanning studies in humans that reveal how specific reward-related brain regions "alert" the brain's learning and memory regions to promote memory formation. In their studies, the researchers asked volunteers to participate in two types of reward-related tasks as they scanned the subjects' brains using functional magnetic resonance imaging. In this technique, harmless magnetic fields and radio waves are used to detect regions of higher blood flow in the brain, which reflects higher activity. In the first task, the researchers aimed at identifying the region involved in anticipating rewards. This task involved presenting the subjects with such symbols as circles or squares that indicated an amount of money the subjects could gain or lose--from no money to $5--by rapidly responding to a subsequently presented target by pressing a button. The subjects were notified immediately whether they had received the reward. The researchers found that reward anticipation activated specific brain structures in the "mesolimbic" region involved in the processing of emotions.

Keyword: Learning & Memory
Link ID: 8875 - Posted: 05.04.2006

DALLAS — — By deleting a gene in certain parts of the brain, researchers at UT Southwestern Medical Center have created mice that show deficits in social interaction that are reminiscent of humans with autism spectrum disorders. The investigators also found physical abnormalities in the brains that mimic some cases of autism, showing that the research animals can be useful in studying the mysterious condition. The finding — to be published in the May 4 issue of the journal Neuron — confirms recent indications that a mutation in this particular gene could cause at least some forms of autism, said Dr. Luis F. Parada, director of the Center for Developmental Biology and the study's senior author. Dr. Parada also directs the Kent Waldrep Center for Basic Research on Nerve Growth and Regeneration. "The exciting thing about this mouse is it helps us to zero in on at least one anatomic location of abnormality, because we targeted the gene to very circumscribed regions of the brain," he said. "In diseases where virtually nothing is known, any inroad that gets into at least the right cell or the right biochemical pathway is very important." Autism is a brain disorder in which people have trouble with communication and social interaction and engage in repetitive movements. Usually manifesting in childhood, it affects about one in every 250 people, primarily males. Copyright 2006. The University of Texas Southwestern Medical Center at Dallas

Keyword: Autism; Genes & Behavior
Link ID: 8874 - Posted: 06.24.2010

From zebra fish to humans, reproductive hormones govern behavioral responses to courtship signals. A new Emory University study conducted in songbirds suggests that hormones may also modulate the way the auditory system processes courtship signals. In other words, hormones may affect how the birds actually listen to courtship songs at certain times of the year when it's time to reproduce. Like many animals, songbirds put on their reproductive song and dance routine each spring: Male birds perform their finest songs, and female birds respond, hormonally prepped for the breeding season. In this research, Emory neuroscientist Donna Maney examined the auditory areas of the brain to see how estrogen affects the selectivity of song-induced gene expression. Dubbed the "genomic response," this is a highly specific process wherein genes are turned on to perform as they're programmed. "Our work suggests that estrogen, which is normally high only during the breeding season, may actually alter auditory pathways and centers," Maney says. "The changes in gene expression reflect changes in the brain that are related to auditory learning and attention." In the study, published in the current issue of the European Journal of Neuroscience, Maney and her research group compared estrogen-treated female white-throated sparrows with females not treated with hormones. The birds listened to recordings of either seductive male song or synthetic, frequency-matched beeps.

Keyword: Learning & Memory; Hormones & Behavior
Link ID: 8873 - Posted: 05.04.2006

By Jay M. Pomerantz, MD Posttraumatic stress disorder (PTSD) is an anxiety disorder that may develop following severe psychological trauma. The person’s immediate response to the event must involve intense fear, helplessness, or horror (or in children, disorganized or agitated behavior).1 Three symptom clusters that characterize the emergence of PTSD are reexperiencing, avoidance and numbing, and hyperarousal. Specific symptoms include flashbacks, nightmares, and feeling detached or estranged following exposure to an extremely traumatic stressful event. These symptoms usually appear within the first 3 months after the trauma, although there may be a delay of months or even years. Terrorist attacks, such as those occurring on September 11, 2001, and combat experiences in Afghanistan and Iraq, have put many Americans at risk for long-term psychological consequences and the development of PTSD. Instead of a gradual recovery from preoccupation with whatever serious life-threatening event a person has experienced, persons with PTSD have traumatic memories with daytime recollections, recurrent nightmares, repetitive flashbacks to the original stressor, and maladaptive avoidance patterns. PTSD will develop in about 25% of persons exposed to extreme trauma, but the likelihood that symptoms will develop in an individual depends on the intensity and kind of traumatic exposure as well as on “individual resilience.”2 In community studies, the reported lifetime prevalence rate is about 8% for PTSD.3 © 2006 CMP Healthcare Media Group LLC,

Keyword: Stress; Learning & Memory
Link ID: 8872 - Posted: 06.24.2010

By Steven A. King, MD, MS First described more than 500 years ago, phantom limb pain (PLP) is a common disorder today; as many as 50% to 80% of patients who undergo amputation report experiencing pain in the missing body part.1 Although it is easy to recognize and diagnose, its cause remains unclear and it can be difficult to manage successfully. Perhaps that's why health care professionals often do not address it. A survey by Hanley and associates,2 for example, found that 53% of patients with PLP and 38% with severe PLP had never been treated for the disorder. Why this problem develops in certain patients remains unclear, although animal studies indicate that there may be a genetic predisposition to PLP.3 PLP most commonly occurs after the amputation of an extremity, but it also has been reported after surgical removal of other parts of the body, most notably after a mastectomy. At one time, PLP was thought to be primarily a psychological problem that reflected both the patient's grieving over the loss of the limb and his or her desire to believe that the limb was still present; however, psychological factors do not appear to be the primary cause. Ephraim and colleagues4 did find the presence of depression to be a predictor of the severity of PLP, although it was similarly associated with residual limb and back pain in amputees. © 2006 CMP Healthcare Media Group LLC

Keyword: Pain & Touch
Link ID: 8871 - Posted: 06.24.2010

Researchers have found that patients with multiple sclerosis (MS) carry a population of immune cells that overreact to Epstein-Barr virus. The virus, which causes mononucleosis and may contribute to some cancers, has long been suspected to play a role in MS. However, the mechanism linking the virus to the disease was poorly understood. Scientists think that MS—which can cause vision problems, muscle weakness, and difficulty with coordination and balance—is a result of the immune system attacking the body's own nervous system. Not everyone who is infected with Epstein-Barr develops MS, but the results of the new study, published in the June 2006, issue of the journal Brain, suggest that some individuals' unusually strong reaction to the virus may trigger the disease. The findings could lead to new therapeutic strategies for better control of the damage caused in this autoimmune disorder. The culprit, the researchers say, may be a population of T cells that helps boost other components of the immune system in response to the virus. "What we discovered in the peripheral blood of the MS patients were T cells that appeared to be primed for action against EBV," said Nancy Edwards, an HHMI-NIH research scholar at the National Institutes of Health (NIH) and co-author of the paper, which was published in advance online. © 2006 Howard Hughes Medical Institute.

Keyword: Multiple Sclerosis
Link ID: 8870 - Posted: 06.24.2010

By Dennis Normile Sushi lovers may now have even more reason to indulge. A Japanese group has found that large supplements of taurine, an amino acid synthesized within the body and also found in seafood, can largely reverse the health hazards of a high-fat diet in mice. Observers caution that more work is needed to prove taurine's protective role and to extend the work to humans. There is evidence that societies with fish-based diets suffer less obesity and related problems than do those that primarily eat meat. Noting that taurine is abundant in fish but not terrestrial animals and that previous animal experiments had shown increased intake of taurine reduced high blood pressure and cholesterol levels, Nobuyo Tsuboyama-Kasaoka, a nutritional biochemist at Japan's National Institute of Health and Nutrition, Tokyo, and colleagues set out to probe the relationship between taurine and obesity. They put groups of mice on high-carbohydrate or high-fat diets. The team found that compared to mice on the high-carbohydrate diet, mice fed a high-fat diet got fat and had lower levels of taurine in the blood and reduced amounts of the enzyme that synthesizes taurine in their adipose tissue, the fat-storing connective tissue found primarily under the skin. © 2006 American Association for the Advancement of Science.

Keyword: Obesity
Link ID: 8869 - Posted: 06.24.2010

The medication naltrexone and up to 20 sessions of alcohol counseling by a behavioral specialist are equally effective treatments for alcohol dependence when delivered with structured medical management, according to results from "Combining Medications and Behavioral Interventions for Alcoholism" (The COMBINE Study). Results from the National Institutes of Health-supported study show that patients who received naltrexone, specialized alcohol counseling, or both demonstrated the best drinking outcomes after 16 weeks of outpatient treatment. All patients also received Medical Management (MM), an intervention consisting of nine brief, structured outpatient sessions provided by a health care professional. Contrary to expectations, the researchers found no effect on drinking of the medication acamprosate and no additive benefit from adding acamprosate to naltrexone. Effect of Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence appears in the current issue of the Journal of the American Medical Association, Volume 295, Number 17, pages 2003-2017. NIH's National Institute on Alcohol Abuse and Alcoholism (NIAAA) launched COMBINE in 2001 to identify the most effective current treatments and treatment combinations for alcohol dependence. The largest clinical trial ever conducted of pharmacologic and behavioral treatments for alcohol dependence, COMBINE was carried out at 11 academic sites that recruited and randomly assigned 1383 recently abstinent, alcohol-dependent patients to one of nine treatment groups (COMBINE Study Design).

Keyword: Drug Abuse
Link ID: 8868 - Posted: 05.03.2006

EAST LANSING, Mich. – Getting beaten up by the neighborhood bully so your buddy can get some tail may seem like a rough life, but it not only works for some lizards, it also gives a fascinating peek into hard-wired altruism in evolutionary biology. Side-blotched lizards spend their year on earth looking to reproduce, and their strategies have lessons about evolution. An article in the May 9 edition of the Proceedings of the National Academy of Sciences provides the first genetic evidence of a trait that the animals recognize and use – even if that trait seems on the surface to be counterproductive. "Cooperation is a tricky thing in terms of evolutionary theory," said Andrew McAdam, an assistant professor of fisheries and wildlife and zoology at Michigan State University and one of the paper's authors. "The question then is why do some organisms cooperate when it seems like being selfish should be the best strategy?" Turns out, it's all in the genes. For two decades, Barry Sinervo from the Department of Ecology and Evolutionary Biology at University of California – Santa Cruz (the study's lead author) has been studying side-blotched lizards of the Central Valley of California, funded by the National Science Foundation. Males break down into three throat colors, flagging different behaviors, which Sinervo has discovered follow "rock-paper-scissors" cycles of lizard lust.

Keyword: Sexual Behavior; Aggression
Link ID: 8867 - Posted: 06.24.2010

Jacqueline Ruttimann Aquatic 'dead zones', oxygen-depleted areas throughout the world's waterways, are not only suffocating marine life but may also be transforming female fish into males. There are about 150 significant oxygen-starved patches of water throughout the world, according to a recent United Nations report1. The most notorious is the Gulf of Mexico, in which the dead zone is approximately 20,000 square kilometres, roughly the size of New Jersey. The oxygen deprivation can be caused by fresh river water sitting above denser salt water, capping it and preventing air from reaching the waters below. The biggest cause, however, is agricultural and industrial run-off of fertilizers and fossil-fuel waste. The nitrogen and phosphorus in these materials cause population bursts of algae and marine creatures called phytoplankton; and when these blooms die they are decomposed by oxygen-consuming bacteria. A burst in activity by these microbes robs the water of oxygen. Such areas are well-known problem spots for the survival of aquatic life, but now it seems the lack of oxygen is having another unexpected effect: tinkering with the sex hormones of fish. "The problem is much bigger than we thought," says ecotoxicologist Rudolf Wu of the City University of Hong Kong, China, whose article in the current issue of Environmental Science and Technology2 shows that hypoxia can cause gender bending. ©2006 Nature Publishing Group

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8866 - Posted: 06.24.2010

People born in the spring or early summer face an increased risk of suicide, UK researchers suggest. A study of 26,916 suicides in England and Wales found babies born in April, May or June had a 17% higher risk of suicide than those born in the autumn. The team suggested the increased risk reflected the fact that more people with alcoholism, depression and mood disorders are born in these months. The research is published in the British Journal of Psychiatry. Scientists have established seasonal birth trends for a number of diseases including some cancers, heart disease and brain tumours. Other research has found more patients with schizophrenia, brain degenerating disease Alzheimer's, epilepsy and sleep disorder narcolepsy are born in December than any other month. Equally, mental illnesses like depression and mood disorders and alcohol dependence are more frequent among those born during the spring and summer. And 10% of suicides in England and Wales occur among people with these disorders. The joint team from St Helen's and Liverpool University and the Institute of Child Health at University College London wanted to see whether there was a link between the two. They analysed information on all deaths from suicide and undetermined injury reporter between 1979 and 2001 in what they say is the biggest study of any possible link to suicide of this kind. (C)BBC

Keyword: Depression; Biological Rhythms
Link ID: 8865 - Posted: 05.02.2006

By Sandra G. Boodman What non-drug treatments work to combat attention-deficit hyperactivity disorder (ADHD)? It's a question more parents are asking doctors, prompted by new concerns about the safety of medicines used to treat a problem that affects an estimated 4.4 million American children. In the past three months, two advisory committees of the Food and Drug Administration have recommended that warning labels on ADHD drugs, most of them stimulants such as Ritalin, be strengthened because of their possible links to rare cardiac problems and vivid hallucinations often involving snakes or bugs. Concerns about misuse and overprescription of ADHD drugs, many of them chemical cousins of amphetamines, are not new. But hope that the common neurobehavioral disorder could be effectively treated without medication was dealt a severe blow seven years ago when a landmark study of nearly 600 school-age children found that medications were the most effective treatment. That study, funded by the National Institute of Mental Health, also found that the best outcomes, measured by parental satisfaction and some academic standards, were the result of "combination" treatment: medications that reduce hyperactivity and improve concentration, and behavior therapy to address some of the more subtle symptoms, such as difficulty with organizational and social skills. © 2006 The Washington Post Company

Keyword: ADHD
Link ID: 8864 - Posted: 06.24.2010

By JAMES GORMAN When it comes to bees making decisions, my question is whether the bee or the hive is the individual. I didn't come up with this question out of the blue, although the blue is actually where most of my ideas come from. The blue is one of my best sources. This question, however, came from reading American Scientist. In the current issue there's an article titled "Group Decision Making in Honey Bee Swarms," by Thomas D. Seeley of Cornell, P. Kirk Visscher at the University of California, Riverside, and Kevin M. Passino at Ohio State. After Dr. Seeley and colleagues present their findings — which I'll get to — they suggest that humans could learn something about group decision making from the bees. The bees, it seems, almost always make good decisions. Groups of humans have a bit more trouble, or as Friedrich Nietzsche wrote, in "Beyond Good and Evil," according to the article, "Madness is the exception in individuals but the rule in groups." Dr. Seeley is a bit more cheery than Nietzsche. I suppose that's not a very high bar, but he writes that groups can make good decisions, and that the success of bees could offer humans some guidance. Copyright 2006 The New York Times Company

Keyword: Language
Link ID: 8863 - Posted: 06.24.2010

By BARRON H. LERNER, M.D. When the woman, having experienced her fourth miscarriage, visited her physician, he gave her a surprising diagnosis: psychosomatic abortion. That is, she had lost the fetuses because of stresses in her life, particularly concerns about her religious affiliation and her husband's unwillingness to help out at home. The doctor's recommended treatment? A series of vitamins, abstaining from sexual intercourse in future pregnancies and, most notably, psychotherapy, intended to explore childhood conflicts and other anxieties. The patient, according to her physician, Dr. Carl T. Javert, an obstetrician at Cornell University Medical College, subsequently had three successful pregnancies. The diagnosis and the treatment fit the era in which they occurred. It was the early 1950's, and the field of psychosomatic medicine — based on the notion that many diseases have their origins in emotional distress — was in its heyday. Was Dr. Javert onto something or was he hopelessly misguided? Do his psychosomatic theories retain any currency today? Throughout history, many doctors and patients have posited that emotions influence health. But it was not until the middle of the 20th century that efforts to prove an association accelerated. A driving force behind psychosomatic medicine was Dr. Franz Alexander, a Hungarian-born psychiatrist trained in the teachings of Freud. Copyright 2006 The New York Times Company

Keyword: Stress; Neuroimmunology
Link ID: 8862 - Posted: 06.24.2010

By CARL ZIMMER The warbles and rattles of a starling seem innocuous enough. But starlings are now the object of a fierce debate about the nature of language. The debate is over what, if anything, the results mean for human language. Some scientists believe that the findings offer new clues to how it evolved. Others dismiss the notion. Human language is unique in the world of animal communication. Humans can convey an infinite range of ideas with a limited vocabulary, because they are not limited to strings of disconnected sounds. Humans can generate meaning by combining words in various ways, building them into clauses and inserting those clauses into sentences. It is possible to come up with all sorts of rules for stringing symbols together. In the 1950's, Noam Chomsky of the Massachusetts Institute of Teachnology ranked classes of rules by their power. A very simple rule might call for one word always to be followed by another word. Dr. Chomsky argued that the rules that govern language must be more powerful. At the very least, they must let people embed smaller groups of words in larger ones again and again — a process sometimes called recursion. Copyright 2006 The New York Times Company

Keyword: Language; Evolution
Link ID: 8861 - Posted: 06.24.2010

SAN FRANCISCO--A new study indicates that cognitive and behavioral problems that underlie attention deficit hyperactivity disorder, or ADHD, are due to a complex interplay of genes and the environment. The Cincinnati Children's Hospital Medical Center study is the first to examine how genes, toxins and gender interact to shape ADHD. "This study shows that certain groups of children have an increased sensitivity to environmental exposures," says Tanya Froehlich, M.D., a physician at Cincinnati Children's and the study's lead author. "More studies like this one are needed to help set exposure standards that adequately protect the most susceptible members of society." The study will be presented at 10:15 a.m. Pacific time Monday, May 1, at the annual Pediatric Academic Societies meeting in San Francisco. The Cincinnati Children's researchers examined the impact of lead exposure on executive function ˙ the ability to plan and organize activities and behaviors. Executive function is impaired in individuals with ADHD. They particularly wanted to determine whether lead's effects are influenced by an individual's underlying genetic and biological make-up, including the impact of gender and variations in the DRD4 dopamine receptor gene. The DRD4 receptor helps regulate brain levels of dopamine, a chemical in the brain that is essential for attention and cognition, and variations in DRD4's composition have been linked to ADHD.

Keyword: ADHD; Neurotoxins
Link ID: 8860 - Posted: 05.02.2006

SANTA CRUZ, CA--A new study of side-blotched lizards in California has revealed the genetic underpinnings of altruistic behavior in this common lizard species, providing new insights into the long-standing puzzle of how cooperation and altruism can evolve. The study, led by researchers at the University of California, Santa Cruz, offers the first evidence in vertebrates of an important theoretical concept in evolutionary biology known as "greenbeard" altruism. "This reflects a major breakthrough in our understanding of how cooperative behavior arises from genes," said Barry Sinervo, professor of ecology and evolutionary biology at UCSC and first author of a paper describing the new findings. The paper will be published in the May 9 issue of Proceedings of the National Academy of Sciences (PNAS) and is currently available in the online early edition of PNAS. The paper describes unrelated male lizards that form cooperative partnerships to protect their territories. These partnerships are often mutually beneficial, enabling both partners to father more offspring than they would on their own. Under some circumstances, however, one male in the pair may have few or no offspring as a result of protecting its partner from the aggressive intrusions of other lizards. This type of cooperation, in which one individual bears all the costs and another unrelated individual receives the benefits, is called "true altruism." These lizards have an annual life cycle, so this behavior may spell the end of the altruistic male's lineage.

Keyword: Sexual Behavior; Evolution
Link ID: 8859 - Posted: 05.02.2006