MADISON - In a painstaking set of experiments in overweight mice, scientists from the University of Wisconsin-Madison have discovered a gene that appears to play an important role in the onset of type 2 diabetes. The finding is important because it provides evidence that the same gene in humans could provide clinicians with a powerful tool to determine the likelihood that some individuals will acquire the condition. Moreover, the finding that the gene works through a pathway not generally studied in the context of diabetes, suggests new avenues to explore in the search for new drugs to treat or prevent the disease, says Alan Attie, a UW-Madison professor of biochemistry and the senior author of the study published this week (May 7) in the journal Nature Genetics. Type 2 diabetes is the most common form of the condition in the United States, with an estimated 16 million Americans afflicted with the disease. It is caused by an inability of the pancreas to produce enough insulin, or by the body's reduced ability to respond to insulin, or both. Insulin is necessary for the body to properly utilize sugar. Often, the development of type 2 diabetes is caused by obesity. Obese individuals tend to have insulin resistance; that is, it takes more insulin for the body to respond normally. Type 2 diabetes occurs when the pancreas is unable to manufacture enough insulin to compensate for the body's increased demand for the hormone, which it does by growing more insulin-producing beta cells or by ramping up insulin secretion.

Keyword: Obesity; Genes & Behavior
Link ID: 8886 - Posted: 05.08.2006

Bruce Bower Bones from a spinal column discovered at a nearly 1.8-million-year-old site in central Asia support the controversial possibility that ancient human ancestors spoke to one another. Excavations in 2005 at Dmanisi, Georgia, yielded five vertebrae from a Homo erectus individual, says anthropologist Marc R. Meyer of the University of Pennsylvania in Philadelphia. The finds occurred in previously dated sediment that has yielded several skulls now attributed to H. erectus (SN: 5/13/00, p. 308: Available to subscribers at http://www.sciencenews.org/articles/20000513/fob1.asp). The new discoveries represent the oldest known vertebrae for the genus Homo, Meyer announced last week at the annual meeting of the Paleoanthropology Society in San Juan, Puerto Rico. The fossils consist of one lumbar, two thoracic, and two cervical vertebrae. Meyer and his colleagues—David Lordkipanidze and Abesalom Vekua, both of the Georgian State Museum in Tbilisi—compared the size, shape, and volume of the Dmanisi vertebrae with more than 2,200 corresponding bones from people, chimpanzees, and gorillas. Copyright ©2006 Science Service.

Keyword: Evolution
Link ID: 8885 - Posted: 06.24.2010

By Robert F. Service Magnetic Resonance Imaging (MRI) machines' knack for peering at soft tissue deep within the body has made them one of the most popular imaging tools. But MRI isn't perfect. It works by beaming radiofrequency pulses into a patient and tracking how this radiation affects the magnetic behavior of tissues. But those pulses must be carefully controlled to prevent them from overheating tissue and injuring patients. Now, a new study could pave the way to a new form of radiofrequency-free MRI scans that would offer several advantages. MRI owes its success to the magnetic behavior of the protons in hydrogen atoms within the body. Those protons have a magnetic moment, which makes them behave essentially like compass needles. To create an image, MRI machines place patients in a strong magnetic field, which causes the protons in the body to align their magnetic compasses with that field. Technicians then send in precisely tuned pulses of radiofrequency energy that knocks some of those compasses out of alignment. By tracking how the needles return to equilibrium, researchers can infer their distribution and thus the makeup of the tissue. But Norbert Müller of Johannes Kepler University in Linz, Austria, and Alexej Jerschow of New York University in New York City wanted to see if they could do away with the need for radiofrequency pulses. © 2006 American Association for the Advancement of Science.

Keyword: Brain imaging
Link ID: 8884 - Posted: 06.24.2010

BOSTON--Scientists have long known that brains need neural activity to mature and that sensory input is most important during a specific window of time called the "critical period" when the brain is primed for aggressive learning. Vision, hearing and touch all develop during such critical periods, while other senses, such as the olfactory system, maintain lifelong plasticity. The visual system provides an exemplary model for studying developmental plasticity, however, because of the pioneering work of Nobel prize-winning HMS researchers David Hubel and Torsten Wiesel describing the visual system's structure, prerequisite knowledge for investigating its flexibility. Although visual plasticity has been studied for over 40 years, exactly how sensory experience interacts with the built-in machinery that permits the brain to change its circuits is only beginning to be understood. A new study focusing on the molecular roots of plasticity has found that visual stimulus turns up the expression of some genes and turns down the expression of others, somewhat like a conductor cueing the members of an orchestra. The study also found that during different stages of life in rodents, distinct sets of genes spring into action in response to visual input. These gene sets may work in concert to allow synapses and neural circuits to respond to visual activity and shape the brain, reports the May issue of Nature Neuroscience.

Keyword: Development of the Brain; Vision
Link ID: 8883 - Posted: 05.06.2006

BUFFALO, N.Y. -- When trying to lie your way through any situation, keep a tight rein on your zygo maticus major and your orbicularis oculi. They'll give you away faster than a snitch. So says social psychologist Mark Frank, whose revolutionary research on human facial expressions in situations of high stakes deception debunks myths that have permeated police and security training for decades. His work has come to be recognized by security officials in the U.S. and abroad as very useful tool in the identification and interrogation of terrorism suspects. By applying computer technology to the emotion-driven nature of nonverbal communication, Frank, a professor of communication in the School of Informatics at the University at Buffalo, has devised methods to recognize and accurately read the conscious and unconscious behavioral cues that suggest deceit. His research already is employed by investigative bodies around the world and, Frank says, "It can be applied to the training of security checkpoint personnel to help them identify and decode 'hot spots,' the subtle conversational cues and fleeting flashes of expression that betray buried emotions or suggest lines of additional inquiry." © 2006 University at Buffalo.

Keyword: Emotions; Stress
Link ID: 8882 - Posted: 06.24.2010

By Shankar Vedantam, Washington Post Staff Writer About 300,000 American children have been diagnosed as having autism, according to the first comprehensive national surveys of the developmental disorder. Boys were four times more likely than girls to have the disorder, which is characterized by verbal, social and emotional problems. White families with higher incomes were also more likely to report having children with the disorder, a fact that federal experts said probably reflected unequal access to medical services. The new data came in two surveys released yesterday by researchers at the Centers for Disease Control and Prevention, who said the numbers matched the range found by earlier studies that looked at smaller groups of people. Autism has been dogged by controversy for more than a decade after what appeared to be a sharp increase in diagnoses in the 1990s. Many experts believe the increase reflects changes in diagnostic criteria adopted in 1994, increased public awareness of the problem, and the difficulties in telling apart a number of overlapping conditions that fall under an umbrella known as autism spectrum disorders. Some advocates have blamed a mercury-based preservative in children's vaccines, even though repeated analyses have failed to confirm a link. The new surveys show that Hispanics have a much lower autism rate than whites, but experts said that this probably reflected differences in access to care. © 2006 The Washington Post Company

Keyword: Autism
Link ID: 8881 - Posted: 06.24.2010

Ian Hacking Autism is devastating – to the family. Children can be born with all manner of problems. Some begin life in great pain that can never be relieved, but at least there is a child there. An autistic child – and here I am talking about what’s known as core autism – is somehow not there. ‘Nobody Nowhere’, as the title of Donna Williams’s autobiography (1992) has it. Very often physically healthy (though there is a high incidence of other problems) he – and it is usually he – just does not respond. It is not merely that he does not learn to speak until years after his peers, and then inadequately. He has no affect; he never snuggles. He is obsessed with things and order, but does not play with toys in any recognisable way, and certainly does not play with other children. He mercilessly repeats a few things you say. With no comprehension. He has violent tantrums, not the usual sort of thing, but screaming, hitting, biting, smashing. This alternates with a placid gentleness, maybe even a smile – but not really for you. Serious Down’s syndrome is pretty bad too, but despite all the difficulties, physical and mental, there is a loving little child there. That is what is so dreadful about core autism: your child is an alien. Parents who guide their autistic infant through to adulthood, who create a human being who can be loving, who can to some extent compensate for his deficits, who can find some dignity and maybe a modest type of respected work – they are, in my opinion, heroes. Many parents will be angry with what I have just said. ‘It is not like that at all. Peter is the most lovable little boy. copyright © LRB Ltd, 1997-2006

Keyword: Autism
Link ID: 8880 - Posted: 06.24.2010

Helen Pearson The paralysing dread one feels before an injection or tooth extraction fires up some of the same brain regions involved in feeling pain itself, say researchers who subjected plucky volunteers to electric shocks. Their discovery supports the idea that distraction could ease a nasty wait. Many people prefer to get an awful event over with sooner rather than later. But neuroscientists didn't know what was going on in our brains during this period of suspense, or exactly why we make this decision. Gregory Berns of Emory University School of Medicine, Atlanta, Georgia, and his co-workers scanned the brains of 32 people while they waited for an electric shock to the foot, much like a spark from static electricity. During the experiment, people were offered a series of choices of the intensity of shock they would receive and when they would receive it. When offered the choice of 'sooner' or 'later' for shocks of equal voltage, almost all the participants wanted to get the shock over with straight away. The team called these people 'mild dreaders'. But nine people dreaded the shock so much that they chose a stronger blast sooner over a milder one later on. This group earned the label 'extreme dreaders'. Berns says that most people could probably if they were an extreme dreader from their everyday experience. ©2006 Nature Publishing Group

Keyword: Emotions; Brain imaging
Link ID: 8879 - Posted: 06.24.2010

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