Ewen Callaway In late March, as winter unclenches its frigid grip on upstate New York, a spotted salamander's thoughts turn fleetingly to love. After early spring rains soak the forests where the salamanders live, thousands of the slimy little creatures descend on small vernal pools for the amphibian equivalent of an orgy. "It's sort of a frenzy," says Kelly Zamudio, an ecologist at Cornell University who studies the five-day ritual. "All these males are competing with each other and nudging each other and putting down sperm as quickly as they can." Spotted salamander sex, it turns out, is an evolutionary Easter egg hunt. Males lay scores of sperm-filled pouches onto the leaves and twigs that litter the pond floor, while females pluck away the sperm to fertilize their eggs. The pouches—called spermatophores—look like little soccer trophies, "but made out of jelly," Zamudio says. A female often collects more than a dozen trophies left by various males. Then, "she walks away from this aggregate of males who are going crazy putting down their spermatophores. She's got everything she needs." Zamudio and former student Chris Chandler wanted to know which males passed on their genes most successfully. Since spotted salamanders don't copulate, females have no direct way to assess the potential fathers of their children. So the scientists analyzed DNA collected in the field from males, females and larvae and came to a surprising conclusion. ©2008 Society for Science & the Public

Keyword: Sexual Behavior; Evolution
Link ID: 11538 - Posted: 06.24.2010

By Melinda Wenner Schizophrenia is a devastating illness. One percent of the world’s population suffers from its symptoms of hallucinations, psychosis and impaired cognitive ability. The disease destroys relationships and renders many of its sufferers unable to hold down a job. What could cause such frightening damage to the brain? According to a growing body of research, the culprit is surprising: the flu. If you are skeptical, you are not alone. Being condemned to a lifetime of harsh antipsychotic drugs seems a far cry from a runny nose and fever. And yet studies have repeatedly linked schizophrenia to prenatal infections with influenza virus and other microbes, showing that the children of mothers who suffer these infections during pregnancy are more likely to be diagnosed with schizophrenia later in life. In 2006 scientists at Columbia University asserted that up to one fifth of all schizophrenia cases are caused by prenatal infections. Doctors have known for many years that microbes such as syphilis and Streptococcus can, if left untreated, lead to serious psychiatric problems. Now a growing number of scientists are proposing that microbes are to blame for several mental illnesses once thought to have neurological or psychological defects at their roots. The strongest evidence pertains to schizophrenia, but autism, bipolar disorder and obsessive-compulsive disorder have also been linked to bacterial, viral or parasitic infections in utero, in childhood or in maturity. Some of these infections can directly affect the brain, whereas others might trigger immune reactions that interfere with brain development or perhaps even attack our own brain cells in an autoimmune mistake. © 1996-2008 Scientific American Inc.

Keyword: Schizophrenia; Neuroimmunology
Link ID: 11537 - Posted: 06.24.2010

Antidepressant may treat lazy eye Fluoxetine helps rats rewire their brain's visual centre. Michael Hopkin The drug fluoxetine (Prozac), prescribed to millions of people with mental illnesses such as depression and anxiety, might soon have an unexpected new medical use — as a treatment for lazy eye syndrome. A study of rats with impaired vision shows that daily doses of fluoxetine help their brains' visual centres to rewire themselves and correct the defect. If the drug has a similar effect in humans, it could potentially help the roughly 1–5% of people thought to have amblyopia, or 'lazy eye'. Fluoxetine and other selective serotonin re-uptake inhibitors (SSRIs) are thought to relieve depression by boosting the amount of the mood-related messenger molecule serotonin that is circulating among the brain's cells. But the new research, led by José Fernando Maya Vetencourt of the Scuola Normale Superiore in Pisa, Italy, suggests that it can have other effects too. Maya Vetencourt and his colleagues tested the theory that SSRIs increase the plasticity of the brain's nerve cells — their capacity to make and break connections with each another. It is this feature that underlies the mental wiring of processes such as accurate vision. © 2008 Nature Publishing Group

Keyword: Vision; Depression
Link ID: 11536 - Posted: 06.24.2010

Phil McKenna A lightweight battery-free headset can continuously monitor human brainwaves, and is powered by body heat and sunlight. The portable electroencephalogram (EEG) device resembles a set of headphones. It could provide wireless monitoring of patients at risk of seizures, have cars or other machinery respond to stressed users, or provide new ways to interact with computer games. Researchers at the Interuniversity Microelectronics Centre (IMEC), in Belgium, created the headset. It generates some power using thermoelectric materials which turn heat gradients into electrical energy, using the difference between a warm human head and the cooler surrounding air. A previous prototype relied on that alone, but was sometimes short of power. "If there is a lot of sun, it is quite hot, the temperature difference between the body and the environment is small," says Guy Beaucarne of IMEC. That means thermoelectric materials can harvest less power. Adding two solar panels to the device can address that. "Typically in such conditions you have more sunlight, so the solar generator compensates for the low thermoelectric power." The solar panels also have heat sinks that cool the device to preserve the thermal gradient needed by the thermoelectrics. © Copyright Reed Business Information Ltd.

Keyword: Robotics
Link ID: 11535 - Posted: 06.24.2010

By Lorimer Moseley In a previous, more adventurous stage of life, I hitchhiked around Australia. I got a lift out of Adelaide from a man with one leg, the other having been amputated after a car accident when he was six. There were two remarkable things about this man. The first was that he drove a manual - three pedals, one leg. The second was his remarkable method of gaining relief from an excruciating pain in his missing foot: he would put his prosthetic leg in the exact location he felt his own leg to be, and then drive a screwdriver into the painful spot. As long as he could see it, driving the screwdriver into the exact site of his pain turned it off just like a switch-he called it his 'magic button'. Either he was lying, or something about the screwdriver, and seeing the phantom limb, relieved his pain. I don't reckon he was lying. Such phantoms of missing body parts are generated by the same brain mechanisms that generate the experience of an existing limb. Nearly everyone who has a limb amputated or the nerve supply removed reports experiencing some kind of phantom limb, but only some report persistent phantom limb pain. Those who do, however, report that the pain is very nasty - it is usually untouched by drugs or implanted pain relief devices. It would be ideal to find an inexpensive self-treatment that has almost no side effects, nor risks. Some think that such a treatment may be found in mirrors. Although 19th century neurologists, such as Pierre Janet, had experimented with the mirror treatment, modern versions of the treatment were developed by Vilayanur S. Ramachandran at the University of California, San Diego. A recent letter by Jack Tsao, et. al in the New England Journal of Medicine describes one of the better attempts to elucidate the true value of mirror therapy for phantom limb pain. The researchers randomly assigned 22 lower-limb amputees with phantom limb pain to one of three groups: © 1996-2008 Scientific American Inc.

Keyword: Pain & Touch
Link ID: 11534 - Posted: 06.24.2010

By Greg Miller SAN FRANCISCO, CALIFORNIA--Taking music lessons can strengthen connections between the two hemispheres of the brain in children, but only if they practice diligently, according to a study reported here 14 April at the annual meeting of the Cognitive Neuroscience Society. The findings add to a long-running debate about the effects of musical training on the brain. In 1995, a study led by neurologist and neuroscientist Gottfried Schlaug found that professional musicians who started playing before the age of 7 have an unusually thick corpus callosum, the bundle of axons that serves as an information superhighway between the left and right sides of the brain. Schlaug and colleagues saw this as evidence that musical training can bolster neural connections, but skeptics pointed to the possibility that the musicians had bigger corpora callosa to begin with. Perhaps their neural wiring had enhanced their musical pursuits instead of the other way around. To investigate further, Schlaug, now at Harvard Medical School in Boston, and colleagues including Marie Forgeard and Ellen Winner at Boston College, studied 31 children. The researchers collected detailed magnetic resonance images of the children's brains at age 6 and again at 9. Of the original group, six children faithfully practiced at least 2.5 hours a week in the time between the scans. In these budding musicians, a region of the corpus callosum that connects movement-planning regions on the two sides of the brain grew about 25% relative to the overall size of the brain. Children who averaged only an hour or two of weekly practice and those who dropped their instruments entirely showed no such growth. All of the children practiced instruments, such as a piano or a violin, that required two hands. © 2008 American Association for the Advancement of Science.

Keyword: Hearing; Laterality
Link ID: 11533 - Posted: 06.24.2010

Erin Allday Stanford researchers are participating in a national study to test a new weight-loss therapy that blocks the nerves that tell people when they're hungry and control how the body stores fat. The treatment is considered a less invasive alternative to bariatric surgeries, which typically involve shrinking the stomach by wrapping a tight band around it or bypassing large sections of it and going straight to the rest of the digestive tract. In the new treatment, which has been tested overseas, a device inserted just beneath the skin emits electronic impulses that confuse signals sent on the vagal nerves from the brain to the stomach. In early studies, the impulses made people feel full and satisfied when they'd otherwise be hungry. "It starts in the brain, and works down to the stomach. We're not cutting or sewing or rerouting the anatomy here," said Dr. John Morton, a bariatric surgeon leading the study at Stanford. "It has a lot of potential to help patients lose weight." The treatment is called VBLOC therapy, for vagal blocking. Stanford is one of 13 sites around the country participating in the study, being funded by medical device company EnteroMedics. Researchers hope to sign up 250 to 300 volunteers, about 50 of them in the Bay Area, and study them for five years. © 2008 Hearst Communications Inc

Keyword: Obesity
Link ID: 11532 - Posted: 06.24.2010

The French National Assembly has passed a groundbreaking bill which seeks to criminalise the promotion in the media of extreme thinness. The bill targets pro-anorexia websites and publications that encourage girls and young women to starve themselves. It will affect websites, fashion houses, magazines and advertisers. If approved by France's upper house, those found to have encouraged severe weight loss could be fined up to 45,000 euros and face three years in prison. French Health Minister Roselyne Bachelot said the proposed law would help stop advice on how to become ultra-thin being spread through pro-anorexia sites on the internet. "Encouraging young girls to lie to their doctors, advising them on foods that are easier to regurgitate and inciting them to beat themselves up each time they eat is not freedom of expression," Ms Bachelot told the assembly. "These messages are death messages. Our country must be able to prosecute those who are hiding behind these websites," she said. Jacques Domergue, a lawmaker supporting the bill, said that the intention was to send a strong message to society. (C)BBC

Keyword: Anorexia & Bulimia
Link ID: 11531 - Posted: 04.16.2008

By temporarily severing the brain's blood supply and damaging the body's vital control centers, a stroke can change every aspect of the sufferer's life. Here, in their own words, are the stories of people coping with the aftermath of stroke. Video: Crucial Facts About Stroke Audio Slide Show: Retraining the Brain Interactive Graphic: Stroke, an Animation Copyright 2008 The New York Times Company

Keyword: Stroke
Link ID: 11530 - Posted: 04.16.2008

If plaques and tangles in the brain cause Alzheimer's Disease, why do some people with affected brains stay sharp into their nineties? Neurologist and researcher Deniz Erten-Lyons is sizing up why certain old folks have both brain plaques and intact memories. She says these special seniors have bigger brains. As she reported to the American Academy of Neurology, her team from Oregon Health and Science University and Portland's VA Medical Center did post-mortem autopsies on research volunteers involved in long-term aging studies. After grouping together the twelve research subjects who fit their main criteria — lots of brain plaques and clear thinking and good memory before death — the researchers tried to figure out what kept this special group mentally healthy during life. "These twelve people — even though they were in their nineties — were able to function, live independently… do their day-to-day functions without any assistance," says Erten-Lyons. When she compared these twelve people to people who did have Alzheimer's Disease and the associated brain lesions, she found a surprise. "The group that died with sharp minds had larger brains" compared to the Alzheimer's Disease group, she says. © ScienCentral, 2000-2008.

Keyword: Alzheimers; Intelligence
Link ID: 11529 - Posted: 06.24.2010

Matt Kaplan Humans don't have the monopoly on drunken behaviour. New research shows that under-the-influence bats are more likely than their sober counterparts to eat junk food. Knowing that fruit-eating bats frequently encounter fermenting fruits, Francisco Sánchez and his colleagues at the Jacob Blaustein Institutes for Desert Research at Ben-Gurion University of the Negev, Israel, decided to investigate what effects, if any, consumption of ethanol from fermentation had on feeding behaviour. Fermented fruits get bats tipsy.GettyTo explore this, they studied Egyptian fruit bats (Rousettus aegyptiacus) . Twelve bats were placed in a cage and given feeding containers filled with a mixture of soy protein infant formula, sucrose, water and one of six concentrations of ethanol that ranged from 0% to 2%. Each day the bats were given a different concentration of ethanol in their food. Uneaten food was removed and measured. The results showed that bats actively avoided concentrations of ethanol above 1%, yet below that threshold level their behaviour was unchanged. Wondering how hunger might affect this, the researchers ran a similar experiment with hungry bats. © 2008 Nature Publishing Group

Keyword: Drug Abuse; Obesity
Link ID: 11528 - Posted: 06.24.2010

By TARA PARKER-POPE Few products are hated as much as hearing aids. The devices can squeal with feedback and overamplify background noises like the click of a turn signal or whir of a ceiling fan. They must be removed for showering or sleeping, and their batteries die frequently. Many users, out of exasperation, decide they’d rather live with hearing loss. But now scientists have come up with a different kind of hearing aid. While the device, called the Lyric, is being used in only 500 patients, it appears to have overcome many of the problems associated with traditional hearing aids — without the expense and uncertainty of surgery and anesthesia. The Lyric, made by InSound Medical of Newark, Calif., is hidden deep inside the ear canal, just four millimeters (about one-sixth of an inch) from the ear drum. While doctors for years have been implanting hearing devices in the middle ear, the Lyric is not an implant: it can be removed with a small magnet. It is worn 24 hours a day, and its batteries last one to four months. Typically, anything that clogs the ear canal would trap moisture and pose an infection risk, but the Lyric is surrounded by a spongy material that allows moisture to escape. Because it sits so close to the ear drum, doctors say that it works more efficiently and that sounds are more natural because they don’t have to be amplified as much. Copyright 2008 The New York Times Company

Keyword: Hearing
Link ID: 11527 - Posted: 06.24.2010

By ANAHAD O’CONNOR Already burdened with the minor mishaps that arise from living in a world designed for righties, their lot in life seemed to worsen considerably in the 1980s, when a study argued that southpaws had several times the risk of chronic headaches — and immune disorders — as their right-handed counterparts. The reason, it was theorized, had something to do with variations in fetal brain development, though no precise explanation was given. But a raft of evidence now suggests that the migraine finding, though intriguing, was less fact than statistical artifact. A more extensive study published in March by German scientists examined a group of 100 patients who had received a diagnosis of migraine based on standards set by the International Headache Society. After finding no evidence of a link between handedness and migraines, the scientists pooled data from five other studies and conducted a meta-analysis. Still, there was no evidence of a relationship — a conclusion echoed by many similar studies. Several studies have also examined whether there is any relationship between left-handedness and increased risk of immune disorders. The findings are inconclusive. Proponents argue that fetal exposure to high levels of testosterone could be responsible, and they point out that left-handedness is more common in men than women. Critics say more research is needed. THE BOTTOM LINE Most studies have found that being left-handed does not increase the risk of migraines. Copyright 2008 The New York Times Company

Keyword: Laterality; Pain & Touch
Link ID: 11526 - Posted: 06.24.2010

By RICHARD A. FRIEDMAN, M.D. “I’ve grown up on medication,” my patient Julie told me recently. “I don’t have a sense of who I really am without it.” At 31, she had been on one antidepressant or another nearly continuously since she was 14. There was little question that she had very serious depression and had survived several suicide attempts. In fact, she credited the medication with saving her life. But now she was raising an equally fundamental question: how the drugs might have affected her psychological development and core identity. It was not an issue I had seriously considered before. Most of my patients, who are adults, developed their psychiatric problems after they had a pretty clear idea of who they were as individuals. During treatment, most of them could tell me whether they were back to their normal baseline. Julie could certainly remember what depression felt like, but she could not recall feeling well except during her long treatment with antidepressant medications. And since she had not grown up before getting depressed, she could not gauge the hypothetical effects of antidepressants on her emotional and psychological development. Copyright 2008 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 11525 - Posted: 06.24.2010

Using a rodent model of epilepsy, researchers found one of the body’s own neurotransmitters released during seizures, glutamate, turns on a signaling pathway in the brain that increases production of a protein that could reduce medication entry into the brain. Researchers say this may explain why approximately 30 percent of patients with epilepsy do not respond to antiepileptic medications. The study, conducted by researchers at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health, and the University of Minnesota College of Pharmacy and Medical School, in collaboration with Heidrun Potschka’s laboratory at Ludwig-Maximilians-University in Munich, Germany, is available online and will appear in the May 2008, issue of Molecular Pharmacology. "Our work identifies the mechanism by which seizures increase production of a drug transport protein in the blood brain barrier, known as P-glycoprotein, and suggests new therapeutic targets that could reduce resistance," said David Miller, Ph.D., a principal investigator in the NIEHS Laboratory of Pharmacology and co-author on the paper. The blood-brain barrier (BBB), which resides in brain capillaries, is a limiting factor in treatment of many central nervous system disorders. It is altered in epilepsy so that it no longer permits free passage of administered antiepileptic drugs into the brain. Miller explained that P-glycoprotein forms a functional barrier in the BBB that protects the brain by limiting access of foreign chemicals.

Keyword: Epilepsy
Link ID: 11524 - Posted: 06.24.2010

Jennifer Viegas -- Female Barbary macaques emit ear-piercing calls when mating, and now researchers have determined other males listen to these sounds with apparent interest. Since the female calls vary, depending on whether or not the male partner has successfully mated, it's believed the eavesdropping males use the sounds to figure out what's going on "in the bedroom" and may even rate the happenings. "The fact that copulation calls are loud and distinctive gives other males of the group the chance to listen in and 'judge' copulations," lead author Dana Pfefferle told Discovery News. Pfefferle, a primatologist at the German Primate Center in Gottingen, and her colleagues previously discovered that female Barbary macaques act a bit like cheerleaders when mating, using their vocalizations to cheer on and stimulate their mates, causing their partners to increase their thrusting rates. The scientists documented two basic types of female mating calls: those linked to partner ejaculation and those linked to no ejaculation. "The peak frequency is higher and the interval between the single units of the call is shorter in ejaculatory compared to non-ejaculatory calls," explained Pfefferle. © 2008 Discovery Communications,

Keyword: Sexual Behavior; Animal Communication
Link ID: 11523 - Posted: 06.24.2010

By Greg Miller SAN FRANCISCO, CALIFORNIA--Imagine not being able to tell your son's voice from that of a complete stranger. Welcome to the life of a 60-year-old British woman known as KH. Although a handful of people have reportedly lost the ability to recognize voices after a stroke or other brain damage, researchers believe KH is the first documented case of someone who never developed this ability in the first place. The case came to light a few years ago when KH read an article in New Scientist magazine about people who can't recognize individuals by face. The article struck a chord, and she contacted the magazine, explaining that she had an analogous voice-recognition problem. For as long as she could remember, the voices of even her closest relatives were indistinguishable. New Scientist contacted Bradley Duchaine, a cognitive neuroscientist featured in the article, and Duchaine invited KH to visit his lab at University College London. A successful management consultant, KH scored average or above on a variety of memory and reasoning tests. Her hearing was normal and a magnetic resonance imaging (MRI) scan of her brain revealed no obvious defects. She told the researchers her problem was limited to recognizing people's voices, explaining that she sometimes introduced herself to business clients by different names so that when they called she could identify them according to who they asked for. © 2008 American Association for the Advancement of Science.

Keyword: Hearing; Language
Link ID: 11522 - Posted: 06.24.2010

Geoff Brumfiel Books and films often dramatize financial-market traders as macho gamblers. Now there may be scientific evidence to back up that pop-culture image: two researchers have linked testosterone levels to the success of traders in one London market. John Coates, a trader-turned-neuroscientist at Cambridge University, UK, started the study after what he saw during his time working the markets: floor traders became frenzied during big winnings, then deeply depressed during downturns. "It was sort of classic manic behaviour," he says. He says that he began to suspect that hormones, specifically testosterone, might be involved because the few female traders appeared to him to be "relatively unaffected". To find out, Coates and his Cambridge colleague Joe Herbert followed 17 male traders for 8 consecutive business days at a firm in London. The researchers took saliva samples from the group before and after the bulk of the day's trading. They analysed the levels of two hormones: testosterone and cortisol, a hormone that is produced in response to uncertainty. © 2008 Nature Publishing Group

Keyword: Hormones & Behavior; Aggression
Link ID: 11521 - Posted: 06.24.2010

There’s no question that the case of 9-year-old Hannah Poling of Athens, Ga., has fueled the controversy about childhood vaccines. But what’s less clear is whether it will help unlock the mysteries of autism. Hannah was 19 months old and developing normally until 2000, when she received five shots against nine infectious diseases. She became sick and later was given a diagnosis of autism. Late last year government lawyers agreed to compensate the Poling family on the theory that vaccines may have aggravated an underlying disorder affecting her mitochondria, the energy centers of cells. (To read more about the decision, click here.) Vaccine critics say the Hannah Poling settlement shows the government has finally conceded that vaccines cause autism. But government officials say Hannah’s case involved a rare medical condition, and there is still no evidence of a link between vaccines and autism. Hannah’s father, Dr. Jon S. Poling, a practicing neurologist in Athens and clinical assistant professor at the Medical College of Georgia, says the case has shifted the autism debate forever and points to a promising new area of research. Writing in The Atlanta Journal-Constitution on Friday, Dr. Poling says there is compelling evidence that mitochondrial disorders, like the one his daughter has, are strongly associated with autism. Copyright 2008 The New York Times Company

Keyword: Autism
Link ID: 11520 - Posted: 06.24.2010

Low doses of a commonly-used anaesthetic could prevent the formation of painful memories, say researchers. The University of California scientists found that sevoflurane gas stopped patients remembering "emotive" images, New Scientist magazine reported. Scans showed it interfered with signals between two key areas of the brain. It is hoped the work could eventually help eradicate rare instances of anaesthetised patients remembering the full horrors of their surgery. While anaesthetic drugs are mainly used to make patients fall unconscious before operations, their effects on the body are frequently far more complex. The Californian researchers, writing in the journal Proceedings of the National Academy of Sciences, were investigating the outcome of much lower doses of the gas than those used prior to surgery. They treated their volunteers either with the anaesthetic, or a placebo gas, and then showed them a series of photographs. Some of these had everyday content, such as a cup of coffee, while others had images designed to provoke a far more powerful emotional response, such as a bloody severed human hand. One week later, the volunteers were asked to recall as many of the images as they could. (C)BBC

Keyword: Learning & Memory
Link ID: 11519 - Posted: 04.14.2008