By NICHOLAS WADE A potentially promising approach to treating Alzheimer’s disease has been developed by researchers studying sirtuin, a protein thought capable of extending lifespan in laboratory animals. Using mice prone to developing Alzheimer’s, the researchers showed that activating sirtuin suppressed the disease and that destroying sirtuin made it much worse. The finding was made by Gizem Donmez, Leonard Guarente and colleagues at the Massachusetts Institute of Technology, who say it raises the hope of treating Alzheimer’s, and possibly other neurodegenerative diseases like Parkinson’s and Huntington’s, with drugs that activate sirtuin. Researchers not involved in the study agreed. “We think it is a scientifically compelling story that ties the sirtuins to the biology of Alzheimer’s disease,” said Dr. Dennis J. Selkoe, an Alzheimer’s expert at Harvard Medical School. But the therapeutic implications, Dr. Selkoe added, “remain quite up in the air.” Another expert, Dr. Juan C. Troncoso of Johns Hopkins University School of Medicine, said the finding “opens a very good avenue, but it’s not without a lot of technical challenges.” Drugs that activate sirtuin already exist, including resveratrol, a minor ingredient of red wine and other foods, and small-molecule chemicals designed to mimic resveratrol. Sirtris, the company that developed the drugs, is testing them against diabetes and other diseases. This generation of drugs does not cross the blood-brain barrier so would not work against Alzheimer’s. Copyright 2010 The New York Times Company

Keyword: Alzheimers; Huntingtons
Link ID: 14282 - Posted: 07.24.2010

By Emily Anthes Perhaps the most unlikely hero to emerge from this summer’s World Cup was Paul the octopus, a lightly spotted invertebrate living in an aquatic center in Germany. Paul earned worldwide fame for successfully “predicting” the winner of eight out of eight soccer games, including the final match. Before each game, Paul’s keepers would place two food-filled boxes, each of which was decorated with one team’s national flag, in the creature’s tank. Whichever box Paul ate from first was considered to be his pick. The octopus nailed it all eight times. Though Paul’s success seems mainly to have been luck — evidence for psychic sports forecasting ability in octopuses is, well, somewhat lacking — if you were looking to consult a brainy animal, you could do worse than an octopus. Research is increasingly revealing that there’s something sophisticated going on inside the octopus’s soft and squishy head. The critters, it seems, are surprisingly smart. Octopuses “make decisions all the time, complicated decisions,” says Roger Hanlon, a senior scientist at the Marine Biological Laboratory in Woods Hole. “People don’t expect that from a creature related to an oyster.” What scientists are discovering about the octopus calls into question many of our assumptions about intelligence. Partly this is because the creatures are so different from the kinds of animals — social vertebrates, especially mammals — that have long been seen as having a monopoly on smarts. Octopuses are members of a class of creatures known as cephalopods, which appeared on the planet even before the first fish, and they are almost as far removed from us primates as another animal can get. And although it has long been theorized that intelligence evolved in social creatures as a way for species that live in groups to navigate the complex social world, the octopus leads a solitary life. © 2010 NY Times Co.

Keyword: Intelligence; Evolution
Link ID: 14281 - Posted: 07.24.2010

In humans, throwing a ball, typing on a keyboard, or engaging in most other physical activities involves the coordination of numerous discrete movements that are organized as action sequences. Scientists at the National Institutes of Health and the Gulbenkian Institute in Portugal have identified brain activity in mice that can signal the initiation and termination of newly learned action sequences. The findings appear online today in the current issue of Nature. “This interesting report should advance our understanding of the neurobiology of movement disorders, and open new avenues of research for their treatment and prevention,” says Kenneth R. Warren, Ph.D., acting director of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the NIH. The study was conducted by Xin Jin, Ph.D. an investigator in the NIAAA Laboratory for Integrative Neuroscience, and Rui M. Costa, D.V.M, Ph.D., principal investigator of the Champalimaud Neuroscience Program at the Gulbenkian Institute. The researchers trained mice to press a lever exactly eight times to receive a sugar-water reward. As the mice learned this task, the researchers monitored brain cell activity in the animals' basal ganglia, deep brain structures that are known to help start and control movement. “We recorded activity in the dorsal striatum and substantia nigra during the learning of novel action sequences,” explained Dr. Jin. “Although previous studies have reported changes in neural activity in these areas during movement, their role in the initiation and termination of newly learned action sequences has not been explored.”

Keyword: Movement Disorders
Link ID: 14280 - Posted: 07.24.2010

By Nicholette Zeliadt Down's syndrome (DS) is an incurable, heritable disorder affecting an estimated 400,000 people in the U.S. It is characterized by impaired cognitive ability and abnormal physical growth. Whereas scientists have long known that DS is caused by inheriting an extra copy of all or part of chromosome 21, the underlying cause of the brain defects common in Down's patients has not been fully gleaned. Now, a collaborative team of scientists working with a mouse model of DS has discovered that just two genes are responsible for the majority of the brain abnormalities present in their animals. The scientists hope that their findings will help scientists understand brain defects in humans with the disorder as well as aid in the development of drugs to treat the cognitive impairment in Down's patients. Previous studies suggest that brain defects in DS mice occur very early, while the mice are still developing embryos. These defects result from abnormalities in how brain neurons communicate with each other—either via excitatory signals, which stimulate other neurons to communicate, or inhibitory signals, which act to prevent other neurons from firing. During embryonic development, the proper ratio of excitatory and inhibitory neurons is established for optimal brain function. These electrical circuits are the basis for memory formation and learning. Human chromosome 21 has more than 300 genes on it. Some of the features of DS—including cognitive deficits, heart defects, gastrointestinal problems and poor muscle tone—could therefore result from having either an additional copy of a single gene on chromosome 21; combinations of extra genes; or from the effects some redundant genes may exert on other chromosomes' genes. This complexity has significantly slowed the pace of researchers' attempts to understand the genetic basis of how such a diverse array of symptoms and abnormalities arise. © 2010 Scientific American,

Keyword: Development of the Brain; Genes & Behavior
Link ID: 14279 - Posted: 07.24.2010

Janelle Weaver A tool that automatically assesses young children's vocalizations should enable faster and more objective measures of language learning in natural environments than current methods allow. And its developers claim that the new tool may also help the early detection of autism by detecting speech abnormalities associated with it. The new method will allow scientists to assess more quickly how children develop speech and language in response to the talk they hear around them, says Kim Oller of the University of Memphis in Tennessee, whose team published its work today in the Proceedings of the National Academy of Sciences1. Because past investigations of language development in natural settings have been hindered by the time-consuming transcription of audio recordings, "their approach could change the field of language development research," says Dorothy Bishop, an expert in developmental language disorders at the University of Oxford, UK. The objective measure of vocal quality could also help to detect speech abnormalities and autism in children, the authors suggest. Previous research has shown that children with Autism Spectrum Disorder have unusual articulation and prosody (patterns of rhythm and sound), but standard diagnostic tests do not cite specific vocal deficiencies. Quantifying vocal abnormalities in autistic children and translating them into a diagnostic procedure has been challenging, says Gordon Ramsay, a speech scientist at Yale University in New Haven, Connecticut. "One of the great goals for years now has been to find objective measures of characteristics or behaviours that can be used to diagnose autism," he says. "This study is the first application of objective measures to detect autism based on speech." © 2010 Nature Publishing Group,

Keyword: Autism; Language
Link ID: 14278 - Posted: 07.20.2010

By NICHOLAS WADE Some 300 million years ago, the living ancestor of humans was a reptile. Like turtles and alligators today, it let the temperature at which its eggs were incubated decide their sex. Birds and mammals, two groups that descended from the reptiles, put sex under the more reliable control of genes, not of temperature. But sex-determining genes pose a severe problem for the organization of a genome. In a series of experiments over the past 15 years, David Page of the Whitehead Institute has reconstructed many of the steps in the evolution of the human sex chromosomes, which he calls “an infinitely rich experiment of nature.” He has now started to analyze a parallel experiment, the sex chromosomes of birds. In humans, men have an X and a Y chromosome, and women two X’s. In reptilian times, the X and the Y were an ordinary pair of chromosomes until the male-determining gene landed on the Y. Thereupon the Y started shedding the genes it held in common with the X and shriveled to a fraction of its former size. Birds have evolved a similar system with a twist — it’s the male that has two of the same chromosomes. Their sex chromosomes are called the Z and W, with males having two Z’s and females a Z and a W. The Z and W are derived from a different pair of ancestral chromosomes than the X and Y, a team led by Daniel W. Bellott and Dr. Page report in the current issue of Nature. The Z’s evolution has in several ways paralleled that of the X, even though each is associated with a different sex. Copyright 2010 The New York Times Company

Keyword: Sexual Behavior
Link ID: 14277 - Posted: 07.20.2010

By TARA PARKER-POPE Does your husband or wife constantly forget chores and lose track of the calendar? Do you sometimes feel that instead of living with a spouse, you’re raising another child? Your marriage may be suffering from attention deficit hyperactivity disorder. An A.D.H.D. marriage? It may sound like a punch line, but the idea that attention problems can take a toll on adult relationships is getting more attention from mental health experts. In a marriage, the common symptoms of the disorder — distraction, disorganization, forgetfulness — can easily be misinterpreted as laziness, selfishness and a lack of love and concern. Experts suggest that at least 4 percent of adults suffer from the disorder; that as many as half of all children with A.D.H.D. do not fully outgrow it and continue to struggle with symptoms as adults; and that many adults with the disorder never got the diagnosis as children. Adults with attention disorders often learn coping skills to help them stay organized and focused at work, but experts say many of them struggle at home, where their tendency to become distracted is a constant source of conflict. Some research suggests that these adults are twice as likely to be divorced; another study found high levels of distress in 60 percent of marriages where one spouse has the disorder. “Typically people don’t realize the A.D.H.D. is impacting their marriage because there’s been no talk about this at all,” said Melissa Orlov, author of the new book “The A.D.H.D. Effect on Marriage,” to be published in September. Copyright 2010 The New York Times Company

Keyword: ADHD; Attention
Link ID: 14276 - Posted: 07.20.2010

Infants who will eventually be diagnosed with autism may be slower to eat solid foods and be fussier eaters, but their growth doesn't seem to be impaired compared with children without the disorders, a new British study suggests. Parents often describe infants diagnosed with autism spectrum disorders (ASD) as "slow feeders," and children with ASDs are often reported to eat a limited range of foods. Compared with 12,901 children without ASDs, 79 children ultimately diagnosed with an ASD were more likely to be slow eaters by six months, Dr. Pauline Emmett of the University of Bristol in England and her colleagues reported in Monday's online issue of the journal Pediatrics. Compared to the control group, children with ASD ate fewer vegetables, salads, and fresh fruit, but also consumed fewer sweets and carbonated drinks, the researchers said. About eight per cent of parents of autistic children reported that, as their kids reached 15 months, they were "very difficult to feed." That compared to about three per cent of kids without autism. Even though children with ASD consumed less of some vitamins and ate a more limited variety of foods, their intake of carbohydrates, protein, fats and total energy were similar to controls. No major differences in weight, height or body mass index were found up to age seven. © CBC 2010

Keyword: Autism; Development of the Brain
Link ID: 14275 - Posted: 07.20.2010

By Daniela Schiller You are on a plane, thirty thousand feet above ground. Four hundred and fifty snakes crawl into the passenger cabin. You think this is terrifying? Hollywood producers certainly gambled on that when they released the 2006 summer blockbuster “Snakes on a Plane.” Israeli scientists, however, have come up with an even creepier scenario. You are in an MRI machine. Your head is fixed in a round cage. Your body is rolled into a narrow tube. Magnetic pulses are beamed into your brain. A meter-and-a-half-long snake is strapped with Velcro atop a small box on a conveyor belt just inches behind your head. Your eyes meet the snake’s beady gaze through a tiny mirror above your head. You can’t move. Why would Uri Nili and Yadin Dudai, two scientists from the Weizmann Institute of Science in Rehovot, Israel, want to put a snake in the MRI scanner with you? Obviously, not to scan the snake’s brain (although this might be an interesting possibility). They wanted to scan your brain while you perform an act of courage. They wanted to push research on fear one step further – from understanding how we passively react to fear, through actively avoiding it, to actually confronting it. FBI agent Neville Flynn (Samuel L. Jackson) could have been an ideal candidate for the experiment. Grabbing and fighting the snakes on the plane with his bare hands, Flynn came to the rescue of the passengers on red-eye flight 121. But there was no FBI or Mossad agent at the Weizmann Institute. The participants in the experiment had to face the snake on their own. All they had were two buttons. Pressing one would roll the snake closer. Pressing the other would slide it away. ‘Advance’ or ‘Retreat’, were their two options. They could choose either one, instructed only to do their best in pulling the snake toward their heads. (See the video here.) © 2010 Scientific American,

Keyword: Emotions
Link ID: 14274 - Posted: 07.20.2010

by Lise Eliot IN 2010 we need to ask afresh just how deep the rabbit hole goes when it comes to gender politics - and how far we are from digging ourselves out. Our beliefs about differences between the sexes have an impact on society vastly out of proportion to the magnitude of those differences, from female scientists defending their mathematical and technical expertise to boys accused of lacking the communication and emotional skills to succeed at school. In truth, women are doing well in science: since 1970, the number of doctorates awarded to women in the US has increased five-fold in physics, nine-fold in computer science and 24-fold in engineering, according to the US Department of Education. And yet just last month we heard John Tierney of The New York Times appearing to echo former Harvard University president Larry Summers's claim that women may be intrinsically incapable of performing at the highest level in such fields. At the same time, boys are stepping away from pursuits like creative writing, foreign languages, art and singing in choirs as they hear they are not "hard-wired" for words or feelings. While young women get the message they can do anything, young men are put off careers in journalism, design, teaching, veterinary practice and psychotherapy, where they were once quite successful. When I set out to write my book Pink Brain, Blue Brain, I had little sense of the controversy surrounding gender differences. I was just a neuroscientist with a daughter and two sons, curious about how their brains might differ and how best to raise them. Now I see how little the science of gender differences has penetrated popular culture and am hoping to set the record straight on behalf of both sexes. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Development of the Brain
Link ID: 14273 - Posted: 07.19.2010

Ecstasy may help boost therapy success in patients with post-traumatic stress disorder, say researchers. A small trial in 20 patients has shown use of the drug is safe and seems to improve the effects of psychotherapy. The US team has now gained approval for a larger study in military veterans, but stresses more research is needed to confirm the finding. It is thought the drug reduces fear enabling patients to get more out of their therapy sessions. Writing in the Journal of Psychopharmacology, the team said patients were selected on strict criteria - they had to have had post-traumatic stress disorder (PTSD) for many years and have failed with conventional treatments. Doctors also excluded those with a history of psychosis or addiction. In the trial, patients were offered two eight-hour psychotherapy sessions scheduled a few weeks apart, with 12 of them given a dose of ecstasy and eight a placebo. Two months later, 10 of the 12 patients given ecstasy responded to the treatment, the researchers said. In contrast, just two out of eight patients offered a placebo showed an improvement. BBC © MMX

Keyword: Stress; Drug Abuse
Link ID: 14272 - Posted: 07.19.2010

by Kate Douglas "What are you laughing at?" Ignoring any aggressive intent, the answer is obvious: I am laughing because something you said amused me. Right? Wrong. According to a classic study of laughter by Robert Provine of the University of Maryland, Baltimore County, and his colleagues, laughter is an unexpectedly serious business. Observing the human animal in its natural habitat - the shopping mall - they documented 1200 instances of laughter, and found that only 10 to 20 per cent of them were responses to anything remotely resembling a joke. Most laughter was in fact either triggered by a banal comment or used to punctuate everyday speech. Furthermore, says Provine in his book Laughter: A scientific investigation, we are 50 per cent more likely to laugh when speaking than when listening, and 30 times gigglier in a social setting than when alone without a social surrogate such as a television. Provine's conclusion was that the essential ingredient for laughter is not a joke but another person. Laughter is far more general than just a response to humour: it is a social glue that we use in all sorts of ways to bind ourselves together. As such, it comes in many guises. Our first laughs occur at between 2 and 6 months of age - even in deaf babies. They are triggered by surprise in a safe situation (think peek-a-boo), and don't just endear babies to their parents. Since laughter is associated with activity in the brain's dopamine reward circuitry, it encourages babies to explore the world by making them feel happy and safe. When infants begin to engage in rough-and-tumble play, laughter signals that the intentions are not serious, allowing children to test physical and social boundaries without serious jeopardy. © Copyright Reed Business Information Ltd.

Keyword: Emotions; Language
Link ID: 14271 - Posted: 07.19.2010

by Catherine Brahic THE French have elevated it to an art form, and even the British have got better at it - but chimps can't cook at all. According to one controversial evolutionary theory, early humans developed a taste for cooked food around 2 million years ago, and this set in motion a series of changes that made us utterly different from any other animal. Now the proponents of the cooked-food hypothesis are presenting fresh evidence in support of the idea - and it all comes down to how you chew. The theory, championed by Richard Wrangham at Harvard University, has divided palaeoanthropologists. In an attempt to convince the doubters, Wrangham and his colleagues have been amassing empirical evidence, including evolutionary adaptations consistent with a diet of heated food, such as the small size of our guts. At the Evolution 2010 conference in Portland, Oregon, at the end of June, Christopher Organ of Harvard and Brown University in Providence, Rhode Island, presented what he and Wrangham say is the best evidence yet that we are adapted to eating cooked food, and that this is the result of events that occurred early on in human evolution. Organ and Charles Nunn, also of Harvard, had predicted that if humans are uniquely adapted to eating cooked food, then we should spend far less time chewing than other primates, as cooked food tends to be softer than raw food. To test this, they gathered data from various primate species and looked at the correlation between chewing time and body size, taking into account how the different species were related to each other. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 14270 - Posted: 07.17.2010

by Linda Geddes NEXT time a sentimental movie makes you cry, blame your serotonin levels. Differences in the neurotransmitter might explain why some people are more prone to crying in emotional situations than others. Frederick van der Veen's team at the Erasmus Medical Centre in Rotterdam, the Netherlands, gave 25 female volunteers a single dose of either paroxetine - a selective serotonin reuptake inhibitor (SSRI) which briefly increases serotonin levels - or a placebo. Four hours later they were asked to watch one of two emotional movies: Brian's Song, in which the hero dies of cancer, or Once Were Warriors, about domestic violence, and to indicate if, and to what extent certain scenes had made them cry. On another day, the women watched the second film with their treatments swapped over. "It didn't matter which movie they saw, we saw a strong and consistent effect of paroxetine," says van der Veen, who presented the results at the Forum of European Neuroscience in Amsterdam last week. "Higher serotonin levels lead to less crying." Although SSRIs are used to treat depression, their mood-boosting effects do not normally show up for around six weeks. The women reported no change in mood in the current study. "We're looking at the direct effect of a single dose of paroxetine," says van der Veen, who adds that the findings might help explain why some people report blunted emotions when taking SSRIs. © Copyright Reed Business Information Ltd

Keyword: Emotions; Depression
Link ID: 14269 - Posted: 07.17.2010

by Andy Coghlan NASAL sprays containing the hormone oxytocin, nicknamed the "cuddle chemical" because it helps mothers bond with their babies, have helped people with schizophrenia. Although the 15 participants used the sprays for three weeks only, most reported measurable improvements in their symptoms in this the first trial to test oxytocin in schizophrenia. "It's proof of concept that there's therapeutic potential here," says David Feifel at the University of California in San Diego, head of the team running the trial. Each participant received oxytocin or a placebo for three weeks, then the opposite treatment for three weeks with a week break in between. On the basis of two standard tests for schizophrenia, taken before and after each block of treatment, participants averaged improvements of around 8 per cent when taking the oxytocin compared with the placebo (Biological Psychiatry, DOI: 10.1016/j.biopsych.2010.04.039). The effects didn't kick in until the final week, suggesting that it takes a while for the hormone to begin acting. "Standard antipsychotic drugs increase their efficacy several weeks later too, so oxytocin fits that profile," says Feifel. Feifel thinks that oxytocin is dampening down the excessive production of the neurotransmitter dopamine, which can trigger schizophrenic symptoms such as hallucinations. © Copyright Reed Business Information Ltd.

Keyword: Schizophrenia; Hormones & Behavior
Link ID: 14268 - Posted: 07.17.2010

By THE NEW YORK TIMES Q. What are the risks of long-term use of prescription drugs to combat insomnia?Claudia, New York, N.Y. A. Dr. Thorpy and Dr. Harris respond: In our sleep center, we use several types of prescription medications to treat insomnia. The most well known are drugs like Ambien (zolpidem), Lunesta (escopiclone) and Sonata (zaleplon) — sometimes referred to as the “Z-drugs” or hypnotics. They all affect a brain structure called the GABA receptor, which is widely found throughout the brain and has many functions; their main effect is to dampen arousal, thereby allowing sleep to occur. There are also non-GABA sleep medications like Rozerem (ramelteon), which reduces arousal by affecting the receptor for the hormone melatonin. Before using any of these medications, it is vital to understand the underlying cause of the insomnia, since other treatments may be more appropriate. If depression is the cause of poor sleep, for example, antidepressants or lifestyle changes may be the most appropriate course. Insomnia has now been shown to be associated with a range of underlying medical and psychological disorders, and it is therefore an important condition to treat. We usually use both behavioral and medication therapy, either alone or together, to get the best response. The aim is to have the patient come off the sleep medication completely when the insomnia resolves. Some people, though, have chronic insomnia that is associated with a medical or psychiatric disorder and need to continue medication very long-term. They can do so without any untoward effects. Copyright 2010 The New York Times Company

Keyword: Sleep
Link ID: 14267 - Posted: 07.17.2010

By GINA KOLATA Marilyn Maldonado is not quite sure why she is at the Memory Enhancement Center in the seaside town of Oakhurst, N.J. “What are we waiting for?” she asks. About 10 minutes later, she asks again. Then she asks again. She is waiting to enter a new type of Alzheimer’s drug study that will, in the boldest effort yet, test the leading hypothesis about how to slow or stop this terrifying brain disease. The disease is defined by freckles of barnacle-like piles of a protein fragment, amyloid beta, in the brain. So, the current thinking goes, if you block amyloid formation or get rid of amyloid accumulations — plaque — and if you start treatment before the disease is well under way, you might have a chance to alter its course. On Tuesday, that plan got a new push. The National Institute on Aging and the Alzheimer’s Association proposed new guidelines for diagnosis to find signs of Alzheimer’s in people who do not yet have severe symptoms, or even any symptoms at all. The guidelines are needed for the new approach to Alzheimer’s drug development. Just about every pharmaceutical company and many biotechnology companies have experimental drugs to block amyloid — there are more than 100 in the pipeline. And the companies would like to show that if they give their drugs early, they can slow or stop the disease. Copyright 2010 The New York Times Company

Keyword: Alzheimers
Link ID: 14266 - Posted: 07.17.2010

By Bruce Bower Here’s some not-so-sobering news for party people, barhoppers and clubgoers. Individuals who inherit a particular gene variant that tweaks the brain’s reward system are especially likely to drink a lot of alcohol in the company of heavy-boozing peers. That’s the preliminary indication of a new study directed by psychology graduate student Helle Larsen of Radboud University Nijmegen in the Netherlands. Adults carrying at least one copy of a long version of the dopamine D4 receptor gene, dubbed DRD4, imbibed substantially more alcohol around a heavy-drinking peer than did others who lacked that gene variant, Larsen’s group reports in a paper published online July 7 in Psychological Science. “Carriers of the long gene may be more attuned to, and influenced by, another person’s heavy drinking than noncarriers are,” Larsen says. Her study provides the first evidence that a gene influences human alcohol use in social situations. Scientists have yet to decipher the precise brain effects of DRD4’s long form. Larsen hypothesizes that in the presence of heavy drinkers, the gene variant may increase dopamine activity in brain areas that amplify alcohol’s appeal as a rewarding social activity. © Society for Science & the Public 2000 - 2010

Keyword: Drug Abuse; Genes & Behavior
Link ID: 14265 - Posted: 07.17.2010

Miriam Frankel A type of brain cell thought to be responsible for supporting other cells may have a previously unsuspected role in controlling breathing. Star-shaped cells called astrocytes, found in the brain and spinal cord, can 'sense' changes in the concentration of carbon dioxide in the blood and stimulate neurons to regulate respiration, according to a study published online in Science today1. The research may shed some light on the role of astrocytes in certain respiratory illnesses, such as cot death, which are not well understood. Astrocytes are a type of glial cell — the most common type of brain cell, and far more abundant than neurons. "Historically, glial cells were only thought to 'glue' the brain together, providing neuronal structure and nutritional support but not more," explains physiologist Alexander Gourine of University College London, one of the authors of the study. "This old dogma is now changing dramatically; a few recent studies have shown that astrocytes can actually help neurons to process information." "The most important aspect of this study is that it will significantly change ideas about how breathing is controlled," says David Attwell, a neuroscientist at University College London, who was not involved in the study. During exercise, the amount of CO2 in the blood increases, making the blood more acidic. Until now, it was thought that this pH change was 'sensed' by specialized neurons that signal to the lungs to expel more CO2. But the study found that astrocytes can sense such a decrease in pH too — a change that causes an increase in the concentration of calcium ions (Ca2+) in the cells and the release of the chemical messenger adenosine-5'-triphosphate (ATP). © 2010 Nature Publishing Group,

Keyword: Glia; Sleep
Link ID: 14264 - Posted: 07.17.2010

by Dolly Krishnaswamy Under the vivid green canopies of the tropics, a young gorilla sneaks up behind another, yanks its hair, and dashes away with a toothy grin on its face. It may seem like harmless fun, but this game of tag has profound implications. In a new study, researchers say the behavior indicates that gorillas know the limits of their social status—and that they play tag to help even the score. Other studies have shown that nonhumans can sense unfairness. In 2005, for example, a group led by psychologist Sarah Brosnan of Yerkes National Primate Research Center in Atlanta reported that capuchin monkeys refused to exchange tokens with an experimenter for a cucumber if they saw a fellow monkey receiving a more desirable grape for its "money." But do animals also sense unfairness in more natural settings? To find out, behavioral biologist Marina Davila Ross of the University of Portsmouth in Hampshire, U.K., and colleagues watched videos collected over 3 years of gorillas at various zoos and reserves in Germany and Switzerland. Almost every afternoon, a couple of the gorillas would begin wrestling with each other. In some instances, gorillas hit their playmates and ran away. Most gorillas seemed to play this game of tag, though older mothers observed from the sidelines. Ross's team noticed a pattern in the play: Gorillas lower on the social ladder were usually the taggers. These gorillas were also twice as likely to instigate another round of the game, and they frequently bared their teeth—a possible indication that they were willing to bite the other gorilla. © 2010 American Association for the Advancement of Science.

Keyword: Development of the Brain; Evolution
Link ID: 14263 - Posted: 07.15.2010