By Michael Balter When it comes to separating humans from other animals, researchers agree that it's what's between the ears that counts most. Indeed, changes in brain-related genes appear to explain the often vast differences between human and chimp cognition. Now scientists have discovered that the spaces between these genes can be just as important. Once thought of as junk, noncoding sequences of DNA fill in the gaps between genes and make up more than 90 percent of our genome. Recently, scientists have discovered that these stretches of DNA contain regulatory elements that control how and when nearby genes are turned on and off (ScienceNOW, 16 August). An international team led by genome researcher Edward Rubin of the Lawrence Berkeley National Laboratory in California wondered how many of these noncoding regions might play a role in human evolution. The team looked at 110,549 human noncoding DNA sequences that seem to have been conserved during mammalian evolution. Using statistical tests, Rubin and his colleagues found 992 sequences that appeared to have undergone changes during human evolution that were not due to simple chance, suggesting that the genetic alterations were due to natural selection. The team then used two existing gene databases, called Gene Ontology and Entrez Gene, to match the noncoding sequences with the functions of the coding genes closest to them. © 2006 American Association for the Advancement of Science.

Keyword: Evolution; Genes & Behavior
Link ID: 9576 - Posted: 06.24.2010

Roxanne Khamsi Applying a gentle electric current to the brain during sleep can significantly boost memory, researchers report. A small new study showed that half an hour of this brain stimulation improved students’ performance at a verbal memory task by about 8%. The approach enhances memory by creating a form of electrical current in the brain seen in deep sleep, the researchers suggest. Jan Born at the University of Luebeck in Germany, and colleagues, recruited 13 healthy medical students for the study and gave them a list of word associations, such as “bird” and “air”, to learn late in the evening. Afterwards, researchers placed two electrodes on the forehead and one behind each ear of the volunteers and let them sleep. The students’ various sleep stages were monitored using an electroencephalogram (EEG) machine. When the students entered a period of light sleep, Born’s team started to apply a gentle current in one-second-long pulses, every second, for about 30 minutes. The EEG readings revealed that this current had put students into a deeper state of sleep. The next morning, the students performed about 8% better on the word memory test than when they underwent the same type of memory experiment without brain stimulation. Born believes this memory boost was due to the pattern of the applied current mimicking that seen in naturally occurring deep sleep, where memory consolidation is thought to take place. © Copyright Reed Business Information Ltd.

Keyword: Sleep; Learning & Memory
Link ID: 9575 - Posted: 06.24.2010

Sportswomen are more prone to injuries at certain times during their menstrual cycle, a study paper suggests. The Swedish research, by a PHD student at Luleå University, included 30 of the nation's top women's soccer teams. Of the 319 female players studied, half received injuries, most commonly to the ankle, knee and thigh. Compared with team mates on the oral contraceptive pill, women were more injury-prone when they had their period than when they were not menstruating. It is not clear exactly why this is, but researcher Inger Jacobson believes it might be related to hormonal fluctuations during the menstrual cycle. For example, the level of a hormone called relaxin, which relaxes or slackens the ligaments, goes up around menstruation. Other studies have drawn similar conclusions. Published work has shown women perform worse on a skill called joint position sense - judging the position of a limb joint, such as the extent to which the knee is bent (flexed) or straight (extended) - around the time of their period. Coordination, postural control, reaction time and judgement may also be affected, experts believe. Oestrogen is known to affect pain perception, thus a sportswoman might be more likely to report injuries during low-oestrogen states, such as around the time of her period, suggests Ms Jacobson. (C)BBC

Keyword: Hormones & Behavior
Link ID: 9574 - Posted: 11.04.2006

In the 2000 presidential campaign, many observers labeled Al Gore as stiff. Lauren Solomon, an image consultant, has worked with politicians and executives for 13 years on how to handle themselves in public speaking situations. She thinks the problem wasn't just his language, it was his body language. "If you don't believe that there is a link between your words and your gestures, then you're only going to get half of the languaged message across to your audience," she says. Colgate University neuroscientist Spencer Kelly found that hand gestures actually influence how our brain processes speech. "Some people think that gestures are actually separate from language," he says. "I believe they are part of language and that means if you're going to understand language, you can't just focus on speech, you have to focus on speech and gesture." Kelly used an electroencephalograph (EEG) machine to measure the electrical brain activity of volunteers while they were shown gestures that contradict what's spoken. "I present gestures that convey one piece of information like gesturing to the shortness of an object and then I present a word like 'tall,'" Kelly says. He found that while witnessing contradictory gestures, volunteers produced the same brain wave pattern as people listening to confusing language -- called the N400 effect. © ScienCentral, 2000-2006.

Keyword: Language
Link ID: 9573 - Posted: 06.24.2010

By Gretchen Vogel Humans excel at following conventions. In France, acquaintances greet one another with a kiss on the cheek. In Japan, they bow. The different greetings have no inherent use on their own--and they would each lose their meaning when performed in the wrong context. But are humans the only animals to use such social conventions? A new study in chimps suggests not; the primates can learn an arbitrary behavior and pass it along to their groupmates. The behaviour in question involved objects that chimps would normally deem useless. Graduate student Kristin Bonnie of the Yerkes National Primate Research Center in Atlanta, Georgia, and her colleagues provided two groups of chimpanzees with either a bucket with a hole cut in the side or a container with a large tube sticking out of the top. Out of sight of the other group members, the researchers trained one high-ranking female from each group to deposit tokens into either the bucket or the tube. The team then sat back and watched to see if that trained behavior would spread. Indeed, the other animals quickly realized that the trained group member was receiving treats--apple or banana slices--for picking up the tokens and placing them in a container. Although treats were available for chimps that used either receptacle, each group followed their leader and used just one of the two options. There was only one exception: A low-ranking female in one group figured out she could get rewards for using the second container, but none of her group members followed her lead. © 2006 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 9572 - Posted: 06.24.2010

Helen Carter, ABC Science Online —Young women obsessed with their own body image eat more food after looking at magazine advertisements that feature the "ideal" thin body, research shows. But those with a healthier body image, who you might expect to be less influenced by the ads, eat less. The Australian study shows that adising affects eating behavior, just not necessarily the way we think. The researchers publish their study in the November issue of the journal Eating Behaviors. Fiona Monro, a PhD student at the University of New South Wales, explained the results. "We would expect people who value the way they look would be reminded by viewing the image and not eat," she said. "We're not sure why we found the reverse but possibly because of stress....[Women obsessed with their appearance] see the idealized image and think about their own body so turn to food. "They might think 'what's the point, I'm never going to look like that, I may as well eat' or the image makes them think they're thinner than they are so they eat more," said Monro. © 2006 Discovery Communications Inc.

Keyword: Obesity; Anorexia & Bulimia
Link ID: 9571 - Posted: 06.24.2010

ATLANTA ( — When Yadong Wang, a chemist by training, first ventured into nerve regeneration two years ago, he didn’t know that his peers would have considered him crazy. His idea was simple: Because neural circuits use electrical signals often conducted by neurotransmitters (chemical messengers) to communicate between the brain and the rest of the body, he could build neurotransmitters into the material used to repair a broken circuit. The neurotransmitters could coax the neurons in the damaged nerves to regrow and reconnect with their target organ. Strange though his idea might have seemed to others in his field, Wang, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, discovered that he could integrate dopamine, a type of neurotransmitter, into a polymer to stimulate nerve tissues to send out new connections. The discovery is the first step toward the eventual goal of implanting the new polymer into patients suffering from neurological disorders, such as Alzheimer's, Parkinson’s or epilepsy, to help repair damaged nerves. The findings were published online the week of Oct. 30 in the Proceedings of the National Academy of Sciences (PNAS). “We showed that you could use a neurotransmitter as a building block of a polymer,” said Wang. “Once integrated into the polymer, the transmitter can still elicit a specific response from nerve tissues.” ©2006 Georgia Institute of Technology

Keyword: Regeneration
Link ID: 9570 - Posted: 06.24.2010

NEW YORK (Reuters Health) - Anorexia nervosa runs a longer course in girls than in boys, research shows. One year after undergoing treatment for anorexia, Dr. Michael Strober of the David Geffen School of Medicine at UCLA and colleagues found that girls showed a higher level of continued preoccupation with weight and eating than did boys. And while none of the boys in the current study had relapsed into full-blown anorexia at one year after treatment, 8.2 percent of girls had. The study is the first to look at gender differences in anorexia patients, the study team points out in the International Journal of Eating Disorders. Given that the disease is much more common among females, they note, some researchers have suggested that there may be gender differences in why it develops. To investigate, Strober and colleagues looked at 99 anorexia patients aged 13 to 17, 14 of whom were boys. Both boys and girls had similarly severe symptoms when they entered treatment, the researchers found, and were also equally likely to suffer from anxiety disorders and traits known to be associated with anorexia such as rigidity and perfectionism. However, girls showed greater concern with weight. One year later, the researchers found, the girls reported more concern with weight, shape and eating than the boys, and were more likely to have fallen below their recommended maintenance weight. © 1996-2006 Scientific American, Inc.

Keyword: Anorexia & Bulimia
Link ID: 9569 - Posted: 06.24.2010

Montréal, -- The group of Dr. Michel Cayouette, researcher at Institut de recherches cliniques de Montréal (IRCM), and Dr. Jonah Chan, collaborator at the University of Southern California, will publish in the next issue of the prestigious scientific journal Science, the results of their study that could have a major impact on the treatment of diseases such as multiple sclerosis, and peripheral neuropathies. At a basic level, our nervous system is like a collection of wires that transmit electrical signals encoding our thoughts, feelings, and actions, both conscious and unconscious. The connections in our brain are formed by neurons that extend to each other and to muscles long wires called axons. Just as an electrical wire needs insulation, our axons require an insulating sheath (myelin) that helps to propagate the electrical signal and maximize the efficiency and velocity of these signals in our brain and body. It is this property (myelination) that facilitates the long-distance communication in our nervous system across junctions called synapses, such that a thought can result in the movement of a finger or a toe. Diseases and injury that compromise the integrity of myelin such as multiple sclerosis, or peripheral neuropathies, have dramatic consequences like paralysis, uncoordinated movements, and neuropathic pain. The discovery reported in this study sheds light on the mechanisms that control how myelin is formed during development of the nerves. The article, which will be published in the November 3rd issue of Science, constitutes an important step forward in our understanding of the process of myelination, and opens the way to new research in this field.

Keyword: Multiple Sclerosis
Link ID: 9568 - Posted: 11.03.2006

By Constance Holden For a practice that's been around for thousands of years, scientists understand very little about what goes on when people "speak in tongues." Currently, glossolalia--as it's called--can be found in Pentecostal and Charismatic Christian sects, where those affected believe they are uttering a message directly from God. Now scientists say they have captured glossolalia on brain scans, which link decreased frontal lobe activity to a loss of self control. To conduct the study, psychiatrist Andrew Newberg of the University of Pennsylvania in Philadelphia and his colleagues recruited five African-American women who belong to a local Pentecostal congregation. All had been in the habit of speaking in tongues "almost on a daily basis" for the past 5 years, says Newberg. As a control activity, subjects stood and sang gospel songs with musical accompaniment, moving their arms and swaying. Then they were asked to repeat the behavior, but this time the researchers encouraged them to speak in tongues rather than sing. In each case, the scientists gave the subjects an intravenous injection of a radioactive tracer that provided, in effect, a freeze-frame of which brain areas were most active during the behavior, as indicated by increased blood flow. This was captured by then scanning the women's brains in a single photon emission computed tomography (SPECT) machine. © 2006 American Association for the Advancement of Science.

Keyword: Language
Link ID: 9567 - Posted: 06.24.2010

AFP — Promiscuous females are more likely to give birth to healthier babies than their monogamous sisters, Australian researchers investigating free love among the country's furry fauna have said. Scientists at the Australian National University said they had proven for the first time that frequent sex with multiple partners increased the survival rate of offspring in an animal species. The team's reproductive revelation comes after two years spent probing the sex life of the brown antechinus, a small mouse-sized carnivorous marsupial found in forests in southeastern Australia, which is related to the Tasmanian Devil. Team leader Diana Fisher said there were many theories for why some female animals had multiple sex partners — "whether it's trading sex for food and protection, dealing with infertile males or avoiding the negative effects of inbreeding in species that can't recognize their relatives." However her team is the first to convincingly demonstrate that promiscuity increased the odds of mating with males who had the strongest sperm, she said on Thursday. © 2006 Discovery Communications Inc.

Keyword: Sexual Behavior
Link ID: 9566 - Posted: 06.24.2010

Tracy Staedter, Discovery News — An implantable brain chip that serves as an artificial connection between nerve cells could one day help rehabilitate lost muscle movement in patients who have suffered brain injuries, stroke or paralysis. "We found that when we put in these connections for long periods of time, we induce a reorganization of wiring in the brain," said Andrew Jackson, a senior research fellow in physiology and biophysics at the University of Washington in Seattle. Jackson and his team reported their findings on the so-called Neurochip in a recent issue of the journal Nature. Reorganizing the brain's wiring can be a long and frustrating process for people who have lost muscle use after an injury or stroke. Typically, they must spend many hours doing physical exercises that encourage brain signals to find new pathways through healthy tissue. But those new pathways are not always complete, which can translate into limited recovery of movement. Or a given pathway may never form at all, which means the person has to find a completely new way to perform a task. © 2006 Discovery Communications Inc.

Keyword: Robotics
Link ID: 9565 - Posted: 06.24.2010

Helen Pearson It has long been held that the ideal human body temperature is a snug 37 degrees Celsius. Our bodies stick rigidly to it when healthy, and high fevers can be deadly. But a new study suggests that 36.5 °C might be even better. Mice cooled by half a degree below normal had a life expectancy 20% longer, or the equivalent of 7-8 additional human years. Researchers have known for decades that a diet containing a third less calories than usual extends the lifetime of mice and other mammals by up to 40% and drops their body temperature by half a degree or more. It was not known whether the cooler temperature helps stave off ageing or is simply a by-product of the low-calorie diet. And this is virtually impossible to test, because mammals maintain the same temperature regardless of the surrounding clime. Conti's team managed to cool down mice using genetic engineering. They used a gene called uncoupling protein 2, which diverts the cells' mitochondria from their usual task of making chemical energy, and instead prompts them to release energy as heat. They inserted this gene into a group of brain cells in the animals' hypothalamus and near to the region that senses and controls body temperature, much like a thermostat. The gene effectively heated up the thermostat and, as a result, tricked the rest of the body into cooling down by 0.3 to 0.5 °C. ©2006 Nature Publishing Group

Keyword: Obesity
Link ID: 9564 - Posted: 06.24.2010

A reexamination of ancient human bones from Romania reveals more evidence that humans and Neandertals interbred. Erik Trinkaus, Ph.D., Washington University Mary Tileston Hemenway Professor in Arts & Sciences, and colleagues radiocarbon-dated and analyzed the shapes of human bones from Romania's Pe?tera Muierii (Cave of the Old Woman). The fossils, discovered in 1952, add to the small number of early modern human remains from Europe known to be more than 28,000 years old. Results were published in the current issue of the Proceedings of the National Academy of Science. The team found that the fossils were 30,000 years old and principally have the diagnostic skeletal features of modern humans. They also found that the remains had other features known, among potential ancestors, primarily among the preceding Neandertals, providing more evidence there was mixing of humans and Neandertals as modern humans dispersed across Europe about 35,000 years ago. Their analysis of one skeleton's shoulder blade also shows that these humans did not have the full set of anatomical adaptations for throwing projectiles, like spears, during hunting.

Keyword: Evolution
Link ID: 9563 - Posted: 11.03.2006

ANN ARBOR, Mich.---The unassuming C. elegans nematode worm, a 1-millimeter workhorse of the genetics lab, is quite similar to human beings in its genetic susceptibility to nicotine dependence, according to University of Michigan researchers. This finding should allow researchers to better understand how nicotine dependence works, and perhaps devise new ways to block the craving that keeps humans smoking cigarettes. Nicotine is the addictive substance in tobacco. Dependence on nicotine drives many of the most preventable causes of death in the U.S. and is a worldwide health problem. A team led by X.Z. Shawn Xu, assistant research professor at the Life Sciences Institute and assistant professor of physiology at U-M Medical School, has completed a series of experiments which establish that C. elegans can get hooked on nicotine. Like humans, the nicotine-sensitive worms showed acute responses to nicotine exposure, as well as tolerance, sensitization and withdrawal. "It turns out that worms exhibited behavioral responses to nicotine that parallel those observed in mammals," said Xu, whose name is pronounced Shoo. "But it is much easier to identify novel functions of a gene in worms." Xu and his team found that the genes known to underlie nicotine dependence in mammals are also present in the worms. Having established worms as a model, the Xu team then tried to identify new genes important for nicotine dependence.

Keyword: Drug Abuse
Link ID: 9562 - Posted: 11.03.2006

Roxanne Khamsi Monkeys that are abused as infants develop a specific brain change that makes them more likely to mistreat their own offspring, a new study shows. The findings may help explain why child abuse in humans often perpetuates from one generation to the next, the researchers say. Dario Maestripieri at the University of Chicago in Illinois, US, and colleagues found that baby rhesus monkeys that endured high rates of maternal rejection and mild abuse in their first month of life produced less of the brain chemical serotonin. Low levels of serotonin are associated with anxiety and depression and impulsive aggression in both humans and monkeys. The team followed a group of newborn rhesus monkeys with mothers that abused and rejected them. They also studied eight newborn monkeys taken from their birth mothers and placed with abusive ones instead. Analysis of the monkeys’ brain fluid revealed that those reared by abusive mothers or abusive foster mothers had 10% to 20% less serotonin than monkeys who had grown up without maternal abuse. This supports the idea that the drop in serotonin results from mistreatment, rather than a genetic predisposition, says Maestripieri. © Copyright Reed Business Information Ltd

Keyword: Aggression; Stress
Link ID: 9561 - Posted: 06.24.2010

By Rob Stein A substance found in red wine protected mice from the ill effects of obesity and extended their life spans, raising the tantalizing prospect that the compound could do the same for humans and may also help people live longer, healthier lives, researchers reported yesterday. The substance, called resveratrol, enabled mice that were fed a high-calorie, high-fat diet to live normal, active lives despite becoming obese -- the first time any compound has been shown to do that. Tests found that the agent activated a host of genes that protect against aging, essentially neutralizing the adverse effects of the bad diet on the animals' health and longevity. Although much more work is needed to explore the benefits and safety of the substance, which is sold over the counter as a nutritional supplement, the findings could lead to the long-sought goal of extending the healthy human life span, experts said. Preliminary tests in people are underway. "We've been looking for something like this for the last 100,000 years, and maybe it's right around the corner -- a molecule that could be taken in a single pill to delay the diseases of aging and keep you healthier as you grow old," said David A. Sinclair, a Harvard Medical School molecular biologist who led the study. "The potential impact would be huge." © 2006 The Washington Post Company

Keyword: Obesity
Link ID: 9560 - Posted: 06.24.2010

Emma Young Have sex and die: that's the lot of a shrew-like marsupial that can't afford to waste time picking out the ideal mate but seems to produce great offspring all the same. It looks like the trick might be down to some high-performance sperm. Antechinus stuartii is a small Australian marsupial with a bizarre sex life. Males gather in a nest, wait for females to turn up and then attempt to mate with as many as possible in what for both sexes is a once-in-a-lifetime sexual orgy. Two weeks later, the males' immune systems fail and they die, while the females go on to produce what is usually their one and only litter before dying a few months later. When Diana Fisher of the Australian National University in Canberra and colleagues took wild animals and allowed females to mate either once with each of three males, or three times with just one male, they found females with multiple mates had three times as many offspring that survived till weaning. Promiscuous these animals may be, but that doesn't mean anything goes genetically speaking. Paternity tests and follow-up experiments revealed that some males sired far more surviving offspring than others. That would make sense, say the researchers, if better-quality males also produce sperm that is able to outcompete the sperm of other males. If so, females do not need to pick out the best males: instead, they can mate with multiple partners and let the males' sperm fight it out (Nature, vol 44, p 89). © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior
Link ID: 9559 - Posted: 06.24.2010

People in western countries tend to have more sexual partners than those in the developing world, a study says. Monogamy is dominant across the world, but multiple partners are more common in rich countries, according to the study published in the Lancet. This was despite developing countries having higher rates of sexually transmitted infections and HIV. London School of Hygiene and Tropical Medicine researchers gathered data from 59 countries for the study. They said factors such as poverty and mobility had more of a role in sexually transmitted infections than promiscuity had. But the team added that the findings showed teenagers were not having sex earlier, contrary to popular beliefs. The study said there had been no universal trend towards earlier sexual intercourse over the past three decades. Almost everywhere, sexual activity began for most men and women between 15 and 19 years of age, with men tending to start earlier. In the UK the average age for men was 16.5 and for women 17.5. Researchers said most people reported only having one sexual partner in the last year. However, those reporting multiple partners were much higher in developed countries - up to a third of under 25s in some areas - whereas only a small percentage in Africa reported the same. And among singletons, westerners were more sexually active as well. Two thirds of men and women without a partner in African countries reported they had had sex recently, compared to three quarters of those in developed countries. (C)BBC

Keyword: Sexual Behavior
Link ID: 9558 - Posted: 11.01.2006

By BENEDICT CAREY Infants who die in their sleep of no apparent cause often have subtle defects in an area of the brain that regulates breathing, heart rate and arousal, doctors are reporting today. Multiple Serotonergic Brainstem Abnormalities in Sudden Infant Death Syndrome (JAMA)The findings, appearing in The Journal of the American Medical Association, provide the strongest evidence yet that a physical abnormality, probably genetic in origin, can help explain what until recently was a matter of speculation for scientists and deep anxiety for new parents: sudden infant death syndrome, or SIDS. More than 2,000 babies a year, about 7 of every 10,000 born in this country, die of SIDS in the first months of their life. Researchers have found that many of the deaths occurred while the babies, most of them boys, were sleeping on their stomachs, often on soft bedding or in a bed with someone else. A public education campaign teaching parents to place infants on their back on a firm mattress has reduced the SIDS rate in recent years. Suspicions of child abuse also cloud many sudden infant deaths, though recent research suggests that abuse is responsible in less than 5 percent of such cases. The new study confirms that a far more important cause is defects in how neurons process serotonin, a brain chemical associated with mood and arousal. Experts said the findings could help doctors develop a diagnostic test for SIDS risk and possibly preventive treatments. Copyright 2006 The New York Times Company

Keyword: Sleep; Development of the Brain
Link ID: 9557 - Posted: 11.01.2006