A drug widely used to treat cancer may cause brain damage, with the effects lasting for years after the end of treatment, research suggests. The drug, 5-fluorouracil (5-FU), is used, alongside others, to treat cancers of the breast, ovaries, colon, stomach, pancreas and bladder. Tests on mice showed it destroys vital cells in the brain that help to keep nerves functioning properly. The University of Rochester study features in the Journal of Biology. The researchers say their findings could explain some of the neurological side effects associated with chemotherapy - a phenomenon often known as "chemo brain". These include memory loss, poor concentration, and in more extreme cases, seizures, impaired vision and even dementia. Until recently they were often dismissed as the by-products of fatigue, depression and anxiety related both to the diagnosis and treatment of cancer. But many patients show symptoms: a previous study by the Rochester team found more than 80% of breast cancer patients reported some form of mental impairment after chemotherapy. The latest study found 5-FU attacks oligodendrocyte cells in the brain and the precursor stem cells from which they originate. These cells play a crucial role in the central nervous system, producing myelin, the protective sheath that keeps nerve fibres in working order. If myelin is not constantly renewed, communication between nerve cells is damaged. The researchers showed that oligodendrocytes virtually disappeared from the brains of mice six months after the animals were treated with 5-FU. (C)BBC

Keyword: Neurotoxins; Glia
Link ID: 11552 - Posted: 04.23.2008

A fish species, which is all female, has survived for 70,000 years without reproducing sexually, experts believe. Scientists from the University of Edinburgh think the Amazon Molly may be employing special genetic survival "tricks" to avoid becoming extinct. The species, found in Texas and Mexico, interacts with males of other species to trigger its reproduction process. The offspring are clones of their mother and do not inherit any of the male's DNA. Typically, when creatures reproduce asexually, harmful changes creep into their genes over many generations. The species will eventually have problems reproducing and can often fall victim to extinction. Scientists at Edinburgh University have been studying complex mathematical models on a highly powerful computing system to look at the case of the Amazon Molly. Researchers calculated the time to extinction for the fish based on modelling genetic changes over many thousands of generations. They are now able to say conclusively, for the first time, the fish ought to have become extinct within the past 70,000 years, based on the current simple models. Scientists believe the fish, which are still thriving in rivers in south-east Texas and north-east Mexico, are using special genetic survival "tricks" to help them stay alive. One theory is that the fish may occasionally be taking some of the DNA from the males that trigger reproduction, in order to refresh their gene pool. Dr Laurence Loewe, of the university's School of Biological Sciences, said: "What we have shown now is that this fish really has something special going on and that some special tricks exist to help this fish survive. "Maybe there is still occasional sex with strangers that keeps the species alive. Future research may give us some answers." (C)BBC

Keyword: Sexual Behavior; Evolution
Link ID: 11551 - Posted: 04.23.2008

A person's employment status, gender and marital status all play a part in how much sleep they get, according to new research from Statistics Canada released Tuesday. Canadians who commute, work longer hours and have more kids get less sleep than the rest of the population — affecting the way they live, according to the report. "When we don't get enough sleep, our productivity and behaviour are affected," reads the report. "This impacts the quality of work we do and the quality of our family and personal life at home." The report, which is published in the Spring 2008 edition of Canadian Social Trends, finds that a higher salary equals less sleep, with people who make $60,000 or more a year sleeping 40 minutes less than those who make $20,000, according to 2005 data. People with high incomes also are more likely to have busy lifestyles, spending less time with their kids and participating less frequently in leisurely pastimes. As a result, their lifestyle is more stressful and results in a poorer quality of sleep. People who work full time get less sleep than those who work part time, sleeping 24 minutes less per night. © CBC 2008

Keyword: Sleep
Link ID: 11550 - Posted: 06.24.2010

Eric Bland -- People who spend hours and hours playing video games exhibit the same personality traits as people with Asperger's syndrome, a form of autism. The new research fuels concerns that video games could further alienate an already isolated group of people and increase mental health problems like depression. In the study, John Charlton of the University of Bolton in England and colleagues examined nearly 400 gamers, most of whom were male, and questioned them about how much they played video games. The researchers didn't specifically study people with Asperger's syndrome. The more time a person spent playing video games, the researchers found, the more likely they were to show three specific traits usually associated with Asperger's syndrome: neuroticism and a lack of extraversion and agreeableness. Charlton suggests that people with Asperger's may be more vulnerable to becoming addicted to playing video games because it allows them to escape into a world where they can avoid face-to-face interactions. © 2008 Discovery Communications, LLC

Keyword: Autism; Attention
Link ID: 11549 - Posted: 06.24.2010

By KAREN BARROW Few people over the age of 10 would list “Happy Birthday” among their favorite songs. But Harvey Alter, now 62, has a special fondness for it. It helped teach him how to talk. One morning in June 2003, Mr. Alter, then a self-employed criminologist, was putting a leash on his dog, Sam, in preparation for a walk around Greenwich Village, where he has lived for 30 years. Suddenly he felt dizzy and disoriented. “My thoughts were intertwined, not making sense,” he said in a recent interview. “I knew I was having a stroke.” At St. Vincent’s Hospital, doctors diagnosed an ischemic stroke, caused by a blockage in blood flow to part of the left half of his brain. As a result, the right side of his body was temporarily paralyzed, the right side of his face drooped, and he had trouble coming up with the right words and stringing them into sentences — a condition called aphasia. Within hours of his stroke, Mr. Alter met with Loni Burke, a speech therapist who now works at Lenox Hill Hospital. At first he was completely nonverbal; within a few days he could say small words. “Mostly, he said, ‘No,’ ” Ms. Burke recalled, “because he was frustrated that he couldn’t speak.” Copyright 2008 The New York Times Company

Keyword: Language; Stroke
Link ID: 11548 - Posted: 06.24.2010

NEW YORK - Children should be screened for heart problems with an electrocardiogram before getting drugs like Ritalin to treat hyperactivity and attention-deficit disorder, the American Heart Association recommended Monday. Stimulant drugs can increase blood pressure and heart rate. For most children, that isn't a problem. But in those with heart conditions, it could make them more vulnerable to sudden cardiac arrest — an erratic heartbeat that causes the heart to stop pumping blood through the body — and other heart problems. About 2.5 million American children and 1.5 million adults take medication for attention-deficit hyperactivity disorder, or ADHD, according to government estimates. Stimulant drugs, like Ritalin, Adderall and Concerta, help children with ADHD to stay focused and control their behavior. The medications already carry warnings of possible heart risks in those with heart defects or other heart problems, which some critics said were driven more by concerns of overuse of the drugs than their safety. The heart group is now recommending a thorough exam, including a family history and an EKG, before children are put on the drugs to make sure that they don't have any undiagnosed heart issues. Copyright 2008 The Associated Press.

Keyword: ADHD
Link ID: 11547 - Posted: 06.24.2010

By CLAUDIA DREIFUS At Harvard, the social psychologist Daniel Gilbert is known as Professor Happiness. That is because the 50-year-old researcher directs a laboratory studying the nature of human happiness. Dr. Gilbert’s “Stumbling on Happiness” was a New York Times paperback best seller for 23 weeks and won the 2007 Royal Society Prize for Science Books. Q. HOW DID YOU STUMBLE ONTO YOUR AREA OF STUDY? A. It was something that happened to me roughly 13 years ago. I spent the first decade of my career studying what psychologists call “the fundamental attribution error,” which is about how people have the tendency to ignore the power of external situations to determine human behavior. Why do many people, for instance, believe the uneducated are stupid? I’d have been content to work on this for many more years, but some things happened in my own life. Within a short period of time, my mentor passed away, my mother died, my marriage fell apart and my teenage son developed problems in school. What I soon found was that as bad as my situation was, it wasn’t devastating. I went on. One day, I had lunch with a friend who was also going through difficult times. I told him: “If you’d have asked me a year ago how I’d deal with all this, I’d have predicted that I couldn’t get out of bed in the morning.” He nodded and added, “Are we the only people who could be so wrong in predicting how we’d respond to extreme stress?” That got me thinking. I wondered: How accurately do people predict their emotional reactions to future events? Copyright 2008 The New York Times Company

Keyword: Emotions
Link ID: 11546 - Posted: 06.24.2010

By HENRY FOUNTAIN Last week in this space, I referred to Joshua D. Wilson, an ocean engineering researcher, in one instance as “Dr. Johnson.” That was a mindless mistake if there ever was one. What was going on in my brain? A new study sheds some light on that question. The study — by Tom Eichele of the University of Bergen in Norway and collaborators including Vince D. Calhoun of the Mind Research Network in Albuquerque — used functional magnetic resonance imaging to look at what goes on in the brain before an error. Participants played a simple game that involved responding to arrows on a computer screen while the fMRI machine measured blood flow and oxygenation in parts of the brain. The idea, Dr. Eichele said, was to see if there were “brain activity patterns that would predict whether or not a response would be erroneous.” As he and his colleagues report in The Proceedings of the National Academy of Sciences, no single “blip” or event signals an error. Rather, brain patterns start to change about 30 seconds before an error is committed. “There are these linear gradients, gradual changes over time,” Dr. Eichele said. Copyright 2008 The New York Times Company

Keyword: Attention; Brain imaging
Link ID: 11545 - Posted: 06.24.2010

Patricia Hluchy How did a man declared brain dead by medical professionals end up back in the land of the living? The emergence of Zack Dunlap's story last month made some people wonder if it's possible to be written off prematurely in the trauma ward. Like a lot of young men in small towns, Zack lived for his wheels – a souped-up all-terrain vehicle. The 21-year-old factory worker spent his free time roaring around the countryside near his hometown, Frederick, Okla., a farming/ranching community of about 4,200. He was so adept at "wheelies" and stunts that his friends called him "Outlaw." Last November, he popped a wheelie that some insist was fatal – even though Zack is now walking and talking again. When he landed, he had to veer suddenly to avoid hitting a fellow ATVer, causing his four-wheeler to flip in the air. Zack, who wasn't wearing a helmet, crashed onto the pavement. Before long he was medevaced to United Regional Healthcare System in Wichita Falls, Tex., about 80 kilometres away, where he was put on a ventilator. Thirty-six hours after the accident, Zack was declared brain dead. The hospital notified the authorities, news reports of his death were published, and preparations were made to harvest his organs. © Copyright Toronto Star 1996-2008

Keyword: Miscellaneous
Link ID: 11544 - Posted: 06.24.2010

Biological, Emotional States Scrutinized By Rick Weiss Twenty years after DNA fingerprints were first admitted by American courts as a way to link suspects to crime scenes, a new and very different class of genetic test is approaching the bench. Rather than simply proving, for example, that the blood on a suspect's clothes does or does not match that of a murder victim, these "second generation" DNA tests seek to shed light on the biological traits and psychological states of the accused. In effect, they allow genes to "testify" in ways never before possible, in some cases resolving long-standing legal tangles but in others raising new ones. Already, chemical companies facing "toxic tort" claims have persuaded courts to order DNA tests on the people suing them, part of an attempt to show that the plaintiffs' own genes made them sick -- not the companies' products. In other cases, defense attorneys are asking judges to admit test results suggesting that their clients have a genetic predisposition for violent or impulsive behavior, adding a potential "DNA defense" to a legal system that until now has held virtually everyone accountable for their actions except the insane or mentally retarded. © 2008 The Washington Post Company

Keyword: Genes & Behavior; Emotions
Link ID: 11543 - Posted: 06.24.2010

Men and women in their early 40s with elevated blood cholesterol levels are more likely to develop Alzheimer's than those with low cholesterol, a report says. The new report is one of the largest studies to link cholesterol to the degenerative brain disease. Alina Solomon of the University of Kuopio in Finland, Rachel Whitmer of the Kaiser Permanente Division of Research in Oakland and their colleagues obtained cholesterol values for 9,752 men and women who were in their 40s from 1964 through 1973. The team found that 504 had developed Alzheimer's by 2007. This study, and other evidence, suggests the disease is influenced by factors that can be changed. Solomon says people can reduce high blood cholesterol with a diet low in saturated fat. Heavy smokers and drinkers develop Alzheimer's years before people who don't drink or smoke as much, a new report says. The study, presented Wednesday at the American Academy of Neurology meeting in Chicago, suggests heavy drinking and smoking might be accelerating damage to the brain, which could lead to Alzheimer's. But the flip side of the study is a message of hope: People who cut back or stop habits such as excessive smoking or drinking might reduce their risk of developing Alzheimer's at a younger age. Instead of struggling with forgetfulness at age 59, such people might delay symptoms until age 65 or 70, says researcher Ranjan Duara of the Mount Sinai Medical Center in Miami Beach. Copyright 2008 USA TODAY,

Keyword: Alzheimers; Drug Abuse
Link ID: 11542 - Posted: 04.22.2008

Commonly used incontinence drugs may cause memory problems in some older people, a study suggests. "Our message is to be careful when using these medicines," said U.S. navy neurologist Dr. Jack Tsao, who led the study. "It may be better to use diapers and be able to think clearly than the other way around." Urinary incontinence sometimes can be resolved with non-drug treatments, he added, so patients should ask about alternatives. Exercises, biofeedback and keeping to a schedule of bathroom breaks work for many. U.S. sales of prescription drugs to treat urinary problems topped $3 billion US in 2007, according to IMS Health, which tracks drug sales. Bladder control trouble affects about one in 10 people age 65 and older, according to the National Institute on Aging, which helped fund the study. Women are more likely to be affected than men. Causes include nerve damage, loss of muscle tone or, in men, enlarged prostate. © The Canadian Press, 2008

Keyword: Learning & Memory
Link ID: 11541 - Posted: 06.24.2010

By Rebecca Morelle Scientists have been able to take control of flies' brains to make females behave just like males. Researchers genetically modified the insects so that a group of brain cells that control sexual behaviour could be "switched on" by a pulse of light. The team was able to get female fruit flies to produce a courtship song - behaviour usually only seen in males. The study, published in the journal Cell, suggests that the wiring in male and female flies' brains is similar. Gero Miesenboeck, from Oxford University, UK, who carried out the research with J. Dylan Clyne from Yale University, US, said: "It is often the case that males have to work very hard to convince females to mate with them. In many animal species, males have to put on elaborate courtship displays to impress females - even the tiny fruit fly." Male fruit flies will vibrate one of their wings to produce a barely audible song, explained Professor Miesenboeck. "And if the female likes that sound, she'll surrender to his advances." Previous research has revealed that a group of 2,000 brain cells are necessary for this courtship behaviour in the insects; however, both male and female fruit flies appear to possess most of these neurons. BBC © MMVII

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 11540 - Posted: 06.24.2010

Patricia Yollin, Chronicle Staff Writer Octopus sex is simple, dull and quick - at least that's what scientists used to think. Instead, it turns out to be complex, sophisticated and rife with petty rivalries. In the most detailed research ever conducted on this topic in the wild, UC Berkeley biologists focused on the mating behavior of the Abdopus aculeatus, one of more than 300 species of octopus. They were stunned at what they learned. "The main surprise was the fact we had this idea that they were completely solitary, with interactions few and far between," said Christine Huffard, lead author on a study recently published in Marine Biology, a science journal. "But they interacted so much more than we ever expected." She discovered that the males were very picky and discriminating, that the females would have sex with just about anybody, and that male competition for females tended to be violent and frequent. "Christine actually followed the aculeatus from dawn to dusk," said Roy Caldwell, a co-author of the study and professor of integrative biology at UC Berkeley. "Nobody had done that kind of intensive field work on any octopus." Huffard, who received her Ph.D. in biology from Cal, came across the species while she was living in Sulawesi, Indonesia, helping a friend with research. "I happened to find them," she recalled. "It was completely serendipitous." Caldwell said, "We went snorkeling and suddenly realized there were octopus everywhere." © 2008 Hearst Communications Inc

Keyword: Sexual Behavior
Link ID: 11539 - Posted: 06.24.2010

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