Giving women a small dose of the male sex hormone testosterone makes them less able to empathise with others, say UK and Dutch researchers. Their findings, in journal PNAS, add weight to the theory that the hormone is significant in the development of autism. Sixteen volunteers given testosterone were less able to judge the mood of facial expressions they were shown. Exposure to the hormone in the womb may be key, it is suggested. Autism is a disorder which, to varying degrees, affects the ability of children and adults to communicate and interact socially. While various genes linked to the condition have been found, the precise combination of genetics and other environmental factors which produce autism is still unclear. The latest study, from the universities of Cambridge and Utrecht, tests the idea that the disorder may be the result of an "extreme male brain", perhaps compromised by exposure to male sex hormones during brain development in the womb. The rate of autism is much higher among boys than it is among girls. Women, on average, have lower levels of the male sex hormone testosterone than men, and 16 volunteers were given a dose of the hormone to see if this affected one of the key areas linked to autism - the ability to empathise. BBC © MMXI

Keyword: Autism; Hormones & Behavior
Link ID: 14984 - Posted: 02.10.2011

By Rebecca Morelle Science reporter, BBC News What you look at can influence how much pain you feel, a study has revealed. Contrary to many people's compulsion to look away during a painful event such as an injection, scientists found that looking at your body - in this case the hand - reduces the pain experienced. The team also showed that magnifying the hand to make it appear larger cut pain levels further still. The study, published in Psychological Science, is shedding light on how the brain processes pain. The researchers say that gaining a better understanding of this could lead to new treatments. The University College London (UCL) and University of Milan-Bicocca research, which was funded by the Biotechnology and Biological Sciences Research Council (BBSRC), was carried out with the help of 18 volunteers. The scientists applied a heat probe to each participant's hand, gradually increasing the temperature. As soon as this began to feel painful, the probe was removed and the temperature was recorded. Patrick Haggard, professor of cognitive neuroscience from UCL, explained: "This gives us a measure of the pain threshold, and it is a safe and reliable way of testing when the brain pathways that underline pain become active." BBC © MMXI

Keyword: Pain & Touch
Link ID: 14983 - Posted: 02.10.2011

Young and middle-aged Americans are experiencing a sharp rise in hospitalization for strokes, says a new study echoing Canadian research that this age group is at greater risk for heart disease than they were in the past. The U.S. numbers, reported Wednesday at an American Stroke Association conference in California, come from the first large U.S. -wide study of stroke hospitalizations broken down by age. Government researchers compared figures in 1994 and 1995 with those in 2006 and 2007. The U.S. Centers for Disease Control and Prevention number show the sharpest increase - 51 per cent - was among men under the age of 35. Strokes rose among women in this age group, too, but not as fast -17 per cent. The Canadian Heart and Stroke Foundation's 2010 annual report describes a similar problem in this country. It showed that between 1994 and 2005, rates of high blood pressure among Canadians in general skyrocketed by 77 per cent, while diabetes rose by 45 per cent and obesity by 18 per cent. It also said that more than 250,000 Canadians in their 20s and 30s had high blood pressure, making them the newest at-risk group. High blood pressure, diabetes and obesity increase a person's likelihood of suffering a stroke. The problem was worst among those aged 35 to 49. The prevalence of high blood pressure in that age group increased 127 per cent, diabetes by 64 per cent and obesity by 20 per cent. © CBC 2011

Keyword: Stroke; Obesity
Link ID: 14982 - Posted: 02.10.2011

Pessimists may be born to take a gloomy view, a study hints. The study is trying to explore any link between genetics and depression. To that end, researchers at the University of Michigan conducted a study of how the brain responds to stress and negative situations for 181 people. They focused on a brain chemical called neuropeptide Y or NPY. People genetically predisposed to produce lower levels of NPY showed stronger responses to negatively charged words like "murderer" when scientists scanned their brain activity. In the first part of the study, participants with low levels of NPY showed a stronger activation in their prefrontal cortex, which is involved in processing emotion. In another experiment, Dr. Brian Mickey of the university's psychiatry department and his colleagues measured responses after subjects were injected with a salt solution in their jaw muscle. The injection caused moderate pain for about 20 minutes with no long-term damage. Subjects with low NPY rated their emotional response to the stress more negatively, both when anticipating it and when they reflected on it afterwards, the study showed. "This tells us that individuals with the risk-associated NPY gene variant tend to activate this key brain region more than other people, even in the absence of stress and before psychiatric symptoms are present," Mickey said in a release. © CBC 2011

Keyword: Emotions; Brain imaging
Link ID: 14981 - Posted: 02.10.2011

By Steve Connor, Science Editor Women have a stronger genetic predisposition to help other people compared with men, according to a study that has found a significant link between genes and the tendency to be "nice". The research, based on an analysis of nearly 1,000 pairs of identical and non-identical twins, found that about half of "prosocial" traits – the willingness to help others – identified in women could be linked with genes rather than environmental upbringing, whereas the figure was just 20 per cent in men. Scientists believe the findings lend further support to the idea that prosocial behaviour has a strong heritable component with some people displaying an innate tendency from childhood. One conclusion from the study, published in the journal Biology Letters, is that some women, and rather fewer men, find it easier than the rest of the population to be generous and helpful towards others, given the right sort of upbringing. "There is a very big debate at the moment about whether humans are altruistic or not," said Gary Lewis, a psychologist at the University of Edinburgh who carried out the research. "There are some people who argue that we have evolved to be altruistic independently of external interventions, and others who argue that we are rather selfish and need a rather conducive external environment for us to be nice to others. ©independent.co.uk

Keyword: Genes & Behavior; Sexual Behavior
Link ID: 14980 - Posted: 02.10.2011

by Richard Knox It's a landmark in the controversial, 30-year-old field of fetal surgery: Surgeons are reporting success in treating a common, serious birth defect called spina bifida — before birth. Spina bifida is a hole in the spine that sometimes allows a loop of the naked spinal cord to protrude outside the body. Such neural-tube defects are down 30 percent because more expectant mothers are taking folic acid pills and dietary supplements. But about 1,500 babies are born with spina bifida every year, and many are destined to have severe lifelong disabilities. A new study, published online in the New England Journal of Medicine, shows that repairing the most severe form of spina bifida during pregnancy can reduce the paralysis and brain damage that often result when the defect isn't corrected until after birth. The surgery is delicate and risky for both mother and fetus. Doctors must make a three-inch incision in the mother's uterus to expose the fetus, which is typically about four inches long at this stage. They then put the exposed piece of spinal cord — between the size of a raisin and an almond — back where it belongs, and suture layers of tissue to keep it in place and prevent cerebrospinal fluid from leaking out. Copyright 2011 NPR

Keyword: Development of the Brain
Link ID: 14979 - Posted: 02.10.2011

By Jennifer Viegas As Valentine's Day cards attest, humans value love and friendship that aren't just forged by family ties, common interests or sexual attraction. Now researchers have determined that such human-like friendships exist among at least five different types of animals. Prior studies determined that elephants, dolphins, some carnivores and certain non-human primates, such as chimpanzees, have the ability -- just as humans do -- to maintain enduring friendships in highly dynamic social environments. A new study, published in the latest issue of the Proceedings of the Royal Society B, adds bats to that list. Female wild Bechstein's bats prefer to literally hang out with certain friends while they also keep loose ties to the rest of their colony. Lead author Gerald Kerth told Discovery News that these bat buddies mirror human ones. Despite all of their "daily chaos, the bats are able to maintain long-term relationships," he said. "We do not work, play and live together with the same individuals all the time during the day and week," he explained. "But nevertheless, we are able to maintain long-term relationships with our friends and our family despite our often chaotic and highly dynamic social lives." Kerth, a professor at the University of Greifswald's Zoological Institute, and colleagues Nicolas Perony and Frank Schweitzer monitored colonies of the bats over a period of five years. Male bats of this species are solitary, but females roost together in bat boxes and tree cavities. They preferred certain companions over the years. © 2011 Discovery Communications, LLC.

Keyword: Animal Communication; Evolution
Link ID: 14978 - Posted: 02.10.2011

by Ferris Jabr Some birds need more than warm feathers or a tropical getaway to survive the winter – they need serious brainpower. Black-capped chickadees that endure harsh winters have bigger and denser memory centres in their brains than those that enjoy more forgiving climes. Timothy Roth of the University of Nevada, Reno, and his colleagues wanted to know the effect of hard winters on the birds' hippocampus – a part of the brain that seems vital for the formation of memories. So they compared the volume of the hippocampus, and the total number of neurons it contained, in populations of black-capped chickadees (Poecile atricapillus) living in Seattle, Washington; Grant, Minnesota; and Presque Isle, Maine. All three locations lie at approximately the same latitude and so birds in all three states have the same hours of daylight in which to forage and build up winter food caches – black-capped chickadees don't fly south for winter. They differ dramatically in their climate, however: winters in Minnesota and Maine are far colder and snowier than in Washington. Despite the consistency of day length across the different environments, birds from Minnesota and Maine had bigger hippocampi than those from Washington. Washington birds have smaller hippocampi, the reasoning goes, because they inhabit a relatively mild climate in which their spatial memory is not as critical to their survival. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; Biological Rhythms
Link ID: 14977 - Posted: 02.10.2011

By Piercarlo Valdesolo Five years ago I had the misfortune of beginning a relationship one week before Valentine’s day. Long hours and many glasses of wine were consumed trying to develop the perfect strategy to court this new woman, and this most saccharine of holidays was proving to be an obstacle. Should I be assertive and make plans with her for the night? Should I assume that we’d be together that evening? Should I assume the contrary? Would presents be involved? If so, of what sort? According to friends’ counsel, my decision would hinge on the message I wanted to communicate. That is, how interested did I want to appear to this woman? The answer to this type of question has long been debated. When trying to establish a relationship is it better to play hard to get or is it better to wear one’s heart on one’s sleeve? Psychologists have had little to say on this matter for quite some time. Some seminal data suggests that honesty is the best policy. If you like him, tell him. After all, it feels good to be liked by others, so to win his heart you should aim to be the source of such feelings. Shower the object of your desire with attention and gifts. Make it clear that you’re into him. But pop culture tells us otherwise. In the words of Vince Vaughn, “If you call too soon you might scare off a beautiful baby who’s ready to party”. Indeed, one of the principle tenets of the burgeoning pick-up artist business is to mildly insult your prospective partner – “neg” her. Let her know that you could truly do without her. © 2011 Scientific American

Keyword: Sexual Behavior
Link ID: 14976 - Posted: 02.10.2011

Catherine de Lange, reporter Jessica Hamzelou, reporter Kate Northstone at the University of Bristol reckons a toddler left to snack on sweets and crisps could be left with a lower IQ later in life. Northstone's team collected data on the eating habits and IQ of almost 4000 children over six years. After accounting for other known influences on IQ, the team found that three-year-old children on a diet high in fat and sugar had lower IQ scores five years later than those fed healthier diets. Eight-year-olds with fruit- and vegetable-laden diets also scored more highly on IQ tests than those on less healthy diets. The results were published today in the Journal of Epidemiological Community Health. The research isn't the first to suggest ways to boost a child's IQ. Children with older dads have also been found to score lower on IQ tests, along with those who are smacked or exposed to cigarette smoke or lead. Last week, a separate study published in The Lancet said that diet could also make a key contribution to attention deficit hyperactivity disorder (ADHD). The authors recommend that children with the condition should eliminate certain foods from their diet before beginning drug treatment. Previous research suggests that some cases of ADHD result from allergic reactions to food. © Copyright Reed Business Information Ltd.

Keyword: ADHD; Intelligence
Link ID: 14975 - Posted: 02.10.2011

By Laura Sanders A cluster of nerve cells have founded their own tiny fight club. These cells, nestled deep in a primitive part of the brain, compel mice to aggressively maul not just intruder males, but also females and blown-up rubber gloves, a study finds. What’s more, the fight cells have an intertwined and thorny relationship with nearby “mate” cells, a discovery that may shed light on human sexual violence. “This is absolutely awesome,” says neuroscientist Newton Canteras of the University of São Paulo, who was not involved in the study. “They [researchers] were able to pinpoint one tiny region in the hypothalamus that is responsible for the aggressive response.” The research, led by Dayu Lin of New York University’s Langone Medical Center, was published in the Feb. 10 Nature. Earlier studies had pointed to the hypothalamus, an almond-sized structure important for hunger, thirst and body temperature, as an aggression center in the brain. Electrical stimulation there made cats and rats attack targets. But researchers didn’t have a clear idea of where in the hypothalamus the fight neurons reside. Now, for the first time, scientists have pinpointed the exact location, says study coauthor David Anderson, a Howard Hughes Medical Institute investigator at Caltech. Researchers found the cells by monitoring the brains of male mice during attacks on male mouse intruders. If the hypothalamus is a country, “these cells are located in one neighborhood in a city in a state in that country,” he says. © Society for Science & the Public 2000 - 2011

Keyword: Aggression
Link ID: 14974 - Posted: 02.10.2011

Evidence that prescription drugs shrink patients' brains would, one might think, suggest only one course of action: stop prescribing them. But the matter turns out to be much more complicated, according to research published today in Archives of General Psychiatry on the effects of antipsychotic drugs in people with schizophrenia1. In the past 15 years, research has indicated that people with schizophrenia have smaller cerebral volumes than the general population, and that this reduction is particularly large in 'grey-matter' structures, which contain the cell bodies of neurons. For instance, one meta-analysis points to 5–7% reductions in the size of the amygdala, hippocampus and parahippocampus2, which are all involved in memory storage and retrieval. But scientists have debated whether the decrease is caused by the disease alone, or whether powerful antipsychotic drugs also have a role. According to the latest findings, the more antipsychotics patients receive, the more likely they are to have a decreased amount of grey matter. The research was led by Beng Choon Ho, a psychiatrist and neuroscientist at the University of Iowa in Iowa City. His team used magnetic resonance imaging (MRI) to scan the brains of 211 patients, administering on average 3 scans per patient over a 7.2-year period1. They found that treatment length and the type and dose of antipsychotic drugs taken were both relatively good predictors of total brain volume change. Use of antipsychotics explained 6.6% of the change in total brain volume and 1.7% of the change in total grey-matter volume. © 2011 Nature Publishing Group,

Keyword: Schizophrenia; Brain imaging
Link ID: 14973 - Posted: 02.08.2011

Alison Abbott Depressed patients who are resistant to other therapies can be helped long term by deep-brain stimulation. The effects can still be seen six years after implanting stimulating electrodes deep inside the brain, according to a follow-up of patients published online in the American Journal of Psychiatry. The study was carried out by a team led by psychiatrist Sidney Kennedy and neurosurgeon Andres Lozano at the University Health Network in Toronto, Canada. They show that, within a year of implantation, depression lifted in 12 of 20 patients — and that the benefits were sustained for up to six years. But two of the patients died by presumed suicide. The good news is that those who showed an early response to deep-brain stimulation maintained that response, says Kennedy. "However the suspected suicides indicate that we have not been able to prevent the course of illness," he adds. According to Thomas Schläpfer, a psychiatrist at the University of Bonn, Germany, the study shows that deep-brain stimulation does actually seem to modify the disease, something that no other treatment has done. "Medication studies in depression always show patients relapsing, even if they respond at first — but responders in this study did not relapse." In the paper, response is defined as a decrease by 50% or more in scores on the Hamilton rating scale for depression. © 2011 Nature Publishing Group

Keyword: Depression
Link ID: 14972 - Posted: 02.08.2011

By Jennifer Welsh Gibbons have regional accents, a new study suggests. While not a sexy Southern drawl, these accents can help scientists identify the species of gibbon singing and where they are from. "Each gibbon has its own variable song but, much like people, there is a regional similarity between gibbons within the same location," lead researcher Van Ngoc Thinh, from the Primate Genetics Laboratory at the German Primate Center, said in a statement. The crested gibbons in the genus Nomascus, which live in the Asian rain forests of China, Laos, Cambodia and Vietnam, use their songs to communicate with other gibbons. They also use singing to bond with mates and define territory. The songs are specifically adapted to travel over long distances through the dense vegetation of the rain forest by concentrating all of the energy into a single frequency, similar to the calls used by rain forest birds. After analyzing the singing of more than 400 gibbons from 92 groups in 24 locations (six different species all together), the researchers compared the song information with the species and location of the gibbons. They also compared it to the genetic variation between these groups. The researchers found that each group of gibbons had its own slightly different way of singing, which varied by location. The songs could be used to pinpoint a gibbon to a species and a location. © 2011 LiveScience.com

Keyword: Language; Animal Communication
Link ID: 14971 - Posted: 02.08.2011

NEW YORK — Smoking marijuana has been linked with an increased risk of mental illness, and now researchers say that when pot smokers do become mentally ill, the disease starts earlier than it would if they didn't smoke pot. This means that serious psychiatric diseases that might not have shown up until kids were in their teens or twenties — or might never had developed at all — are starting in children as young as 12 who smoke marijuana. The link between using pot and developing serious mental illness is strongest in the youngest smokers — 12- to 15-year-olds, or kids even younger, said Dr. Matthew Large in an interview with Reuters Health. "We have to (tell) people who have marijuana in their pockets not to give it to younger people," said Large, who headed up the research at the University of New South Wales in Sydney, Australia. Large and his colleagues looked at thousands of patients with psychotic disorders like schizophrenia. People with psychotic disorders lose touch with reality — usually starting in adolescence or young adulthood. The authors of the new study found that in the subjects who had been pot smokers, the psychotic symptoms began nearly 3 years earlier than in those who had not been marijuana users. Copyright 2011 Thomson Reuters

Keyword: Drug Abuse; Schizophrenia
Link ID: 14970 - Posted: 02.08.2011

By Michelle Roberts Health reporter, BBC News Scientists believe they have discovered the genetic code that makes some people sleepwalk. By studying four generations of a family of sleepwalkers they traced the fault to a section of chromosome 20. Carrying even one copy of the defective DNA is enough to cause sleepwalking, the experts told the journal Neurology. They hope to target the genes involved and find new treatments for the condition that affects up to 10% of children and one in 50 adults. Most often, sleepwalking is a fairly benign problem and something that will be outgrown. Many children will have episodes where they will arise from their sleep in a trance-like state and wander. But more extreme cases of sleepwalking can be deeply disruptive and downright dangerous, particularly when the condition persists into adulthood. Sleepwalkers may perform complex feats such as locating the car keys, unlocking the doors and then driving. There have even been high-profile cases where sleepwalkers have killed during an episode. BBC © MMXI

Keyword: Sleep; Genes & Behavior
Link ID: 14969 - Posted: 02.08.2011

Eating chips, chocolate and cake may be damaging to a child's intelligence, according to researchers at Bristol University. Their study suggests a link between a diet high in processed foods and a slightly lower IQ. Writing in the Journal of Epidemiology and Community Health, they suggest poor nutrition may affect brain development. The British Dietetic Association said more young parents needed to be educated about healthy eating. The eating habits of 3,966 children taking part in the The Avon Longitudinal Study of Parents and Children were recorded at the ages of three, four, seven and eight and a half. The researchers said three types of diet emerged: Processed diets which were high in fat, sugar and convenience foods, traditional diets of meat, potato and vegetables, and health conscious diets of salads, fruit and fish. The children all took IQ tests when they were eight and half. The researchers found a link between IQ and diet, even after taking into account other factors such as the mother's level of education, social class and duration of breast feeding. BBC © MMXI

Keyword: Development of the Brain; Intelligence
Link ID: 14968 - Posted: 02.08.2011

Human brains have shrunk over the past 30,000 years, puzzling scientists who argue it is not a sign we are growing dumber but that evolution is making the key motor leaner and more efficient. The average size of modern humans -- Homo sapiens -- has decreased about 10 percent during that period -- from 1,500 to 1,359 cubic centimeters (91 to 83 cubic inches), the size of a tennis ball. Women's brains, which are smaller on average than those of men, have experienced an equivalent drop in size. These measurements were taken using skulls found in Europe, the Middle East and Asia. "I'd called that a major downsizing in an evolutionary eye blink," John Hawks of the University of Michigan told Discover magazine. But other anthropologists note that brain shrinkage is not very surprising since the stronger and larger we are, the more gray matter we need to control this larger mass. The Neanderthal, a cousin of the modern human who disappeared about 30 millennia ago for still unknown reasons, was far more massive and had a larger brain. The Cro-Magnons who left cave paintings of large animals in the monumental Lascaux cave over 17,000 years ago were the Homo sapiens with the biggest brain. They were also stronger than their modern descendants. Psychology professor David Geary of the University of Missouri said these traits were necessary to survive in a hostile environment. He has studied the evolution of skull sizes 1.9 million to 10,000 years old as our ancestors and cousins lived in an increasingly complex social environment. © 2011 Discovery Communications, LLC.

Keyword: Evolution; Intelligence
Link ID: 14967 - Posted: 02.08.2011

by Douglas Fox A STRANGE contraption, a cross between a deli meat slicer and a reel-to-reel film projector, sits in a windowless room in Cambridge, Massachusetts. It whirs along unsupervised for days at a time, only visited occasionally by Narayanan Kasthuri, a mop-haired postdoc at Harvard University, who examines the strip of film spewing out. It may seem unlikely, but what's going on here may revolutionise neuroscience. Spaced every centimetre along the film are tiny dots, each of which is a slice of mouse brain, one-thousandth the thickness of a sheet of aluminium foil. This particular roll of film contains 6000 slices, representing a speck of brain the size of a grain of salt. The slices of brain will be turned into digital images by an automated electron microscope. A computer will read those images, trace the outlines of nerve cells, and stack the pictures into a 3D reconstruction. In the jargon, they are building the mouse "connectome", named in line with the term "genome" for the sequence of all of an organism's genes, "proteome" for all its proteins, and so on. It's an epic undertaking. The full mouse connectome would produce hundreds of times more data than can be found on all of Google's computers, says Jeffrey Lichtman, the neuroanatomist leading the Harvard team. And yet it's just the beginning. Their efforts could be seen as a dry run for a project that is at least four orders of magnitude greater: mapping the human connectome. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain
Link ID: 14966 - Posted: 02.08.2011

Researchers believed neurons in the brain communicated through physical connections known as synapses. However, EU-funded neuroscientists have uncovered strong evidence that neurons also communicate with each other through weak electric fields, a finding that could help us understand how biophysics gives rise to cognition. The study, published in the journal Nature Neuroscience, was funded in part by the EUSYNAPSE ('From molecules to networks: understanding synaptic physiology and pathology in the brain through mouse models') project, which received EUR 8 million under the 'Life sciences, genomics and biotechnology for health' Thematic area of the EU's Sixth Framework Programme (FP6). Lead author Dr Costas Anastassiou, a postdoctoral scholar at the Californian Institute of Technology (Caltech) in the US, and his colleagues explain how the brain is an intricate network of individual nerve cells, or neurons, that use electrical and chemical signals to communicate with one another. Every time an electrical impulse races down the branch of a neuron, a tiny electric field surrounds that cell. A few neurons are like individuals talking to each other and having small conversations. But when they all fire together, it's like the roar of a crowd at a sports game. That 'roar' is the summation of all the tiny electric fields created by organised neural activity in the brain. While it has long been recognised that the brain generates weak electrical fields in addition to the electrical activity of firing nerve cells, these fields were considered epiphenomenon - superfluous side effects.

Keyword: Miscellaneous
Link ID: 14965 - Posted: 02.08.2011