Childhood brain tumours have fewer genetic mutations than similar tumours in adults, a new genetic mapping study shows. Brain tumours are the leading cause of cancer-related deaths in children. The findings on genetic mutations will be helpful in developing new treatments for medulloblastoma, a brain tumour that mainly affects children, a co-author of the study said. "Now, we must figure out how to put the puzzle together and zero in on parts of the puzzle to develop new therapies," said Dr. Bert Vogelstein of Johns Hopkins University in Baltimore, Md. In this week's online issue of the journal Science, researchers identified genetic changes in tumours taken from 22 children with medulloblastoma and compared them with normal DNA. The researchers found surgically removed child tumours had five to 10 times fewer genetic changes than did tumour samples from adults. Each child tumour sample had an average of 11 mutations. Among the most frequently mutated genes were those affecting signalling pathways key to normal brain development. Newly identified mutations were found in the MLL2 and MLL3 genes, which are known to help suppress tumours and were not previously implicated in medulloblastoma. © CBC 2010

Keyword: Development of the Brain
Link ID: 14804 - Posted: 12.20.2010

By ALLEN G. BREED JACKSONVILLE, N.C. — As she walked through the door, Sabrina Parker's big hazel eyes flared with surprise and she raised a hand to her mouth to stifle a gasp. She was a huge fan of the "Twilight" book and movie series, and her friends and family had transformed this greasy garage into a Sweet 16's dream. Homemade strobe lights illuminated walls decorated like the night sky and plastered with cast posters. All around were balloons in red, white and black. An enormous cake, iced to look like the chess board on one of the book jackets, held 16 blazing candles. The crowd began chanting for Sabrina to blow them out. She bent in close and blew, but the flames barely flickered. She straightened up and shook her head. Realizing her distress, Matt Scozzari stepped closer and told her they would do it together. On the count of three, they leaned in and snuffed them out together. In the three months since he'd first asked her out, Matt had noticed small changes in his girlfriend: The shortness of breath, the slurring in her speech, the weight loss. When he'd ask what was going on, Sabrina would just shrug it off as nothing serious. But Sabrina knew her condition was very serious. About a month after she started seeing Matt, Sabrina learned that she had amyotrophic lateral sclerosis, also known as Lou Gehrig's Disease — the same illness that had killed her mother and grandmother. A doctor told Sabrina it wouldn't be long before she would have to decide whether to go on a ventilator. Copyright 2010 The Associated Press.

Keyword: ALS-Lou Gehrig's Disease
Link ID: 14803 - Posted: 12.20.2010

By TRIP GABRIEL STONY BROOK, N.Y. — Rushing a student to a psychiatric emergency room is never routine, but when Stony Brook University logged three trips in three days, it did not surprise Jenny Hwang, the director of counseling. It was deep into the fall semester, a time of mounting stress with finals looming and the holiday break not far off, an anxiety all its own. On a Thursday afternoon, a freshman who had been scraping bottom academically posted thoughts about suicide on Facebook. If I were gone, he wrote, would anybody notice? An alarmed student told staff members in the dorm, who called Dr. Hwang after hours, who contacted the campus police. Officers escorted the student to the county psychiatric hospital. There were two more runs over that weekend, including one late Saturday night when a student grew concerned that a friend with a prescription for Xanax, the anti-anxiety drug, had swallowed a fistful. On Sunday, a supervisor of residence halls, Gina Vanacore, sent a BlackBerry update to Dr. Hwang, who has championed programs to train students and staff members to intervene to prevent suicide. Copyright 2010 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 14802 - Posted: 12.20.2010

By Steve Connor, Science Editor New ways of diagnosing and treating dozens of brain disorders could soon emerge from a pioneering study of the chemical and genetic makeup of the vital microscopic gaps between nerve cells that control all brain functions. Scientists announced yesterday that they have identified more than a thousand proteins and their related genes which are involved in transmitting electrical messages from one nerve cell to another across the tiny gaps of the brain's many billions of synapses – switches that control brain activity. The researchers said the feat could be compared to the deciphering of the human genome, because knowing the chemical and genetic makeup of the synapses will lead to important new insights into the nature of the many brain disorders that have so far defied adequate scientific explanation. The study identified 1,461 proteins and their genes that make up the so-called "post-synaptic density" of chemicals that control the transmission of each electrical message from one nerve cell to another. The scientists also found that these proteins could be linked directly with 130 brain diseases, including Alzheimer's and Parkinson's. The post-synaptic density is a complex collection of protein molecules that sticks out from the membrane of the second nerve cell of the synapse which receives the chemically transmitted message from the first nerve cell. Scientists believe that this assemblage of proteins is involved in many if not all major brain diseases. ©independent.co.uk

Keyword: Alzheimers
Link ID: 14801 - Posted: 12.20.2010

By GINA KOLATA Marjie Popkin thought she had chemo brain, that fuzzy-headed forgetful state that she figured was a result of her treatment for ovarian cancer. She was not thinking clearly — having trouble with numbers, forgetting things she had just heard. One doctor after another dismissed her complaints. Until recently, since she was, at age 62, functioning well and having no trouble taking care of herself, that might have been the end of her quest for an explanation. Last year, though, Ms. Popkin, still troubled by what was happening to her mind, went to Dr. Michael Rafii, a neurologist at the University of California, San Diego, who not only gave her a thorough neurological examination but administered new tests, like an M.R.I. that assesses the volume of key brain areas and a spinal tap. Then he told her there was something wrong. And it was not chemo brain. It most likely was Alzheimer’s disease. Although she seemed to be in the very early stages, all the indicators pointed in that direction. Until recently, the image of Alzheimer’s was the clearly demented person with the sometimes vacant stare, unable to follow a conversation or remember a promise to meet a friend for lunch. Ms. Popkin is nothing like that. To a casual observer, the articulate and groomed Ms. Popkin seems perfectly fine. She is in the vanguard of a new generation of Alzheimer’s patients, given a diagnosis after tests found signs of the disease years before actual dementia sets in. Copyright 2010 The New York Times Company

Keyword: Alzheimers
Link ID: 14800 - Posted: 12.18.2010

By Emily Singer The common perception is that older people are more conservative investors than their younger counterparts. But brain imaging studies combined with economic analysis are causing neuroscientists to question that idea. Recent research suggests that sometimes older people make riskier and less logical investment decisions than younger people, and that specific changes in the brain associated with aging may underlie those decisions. A better understanding of these changes could help scientists figure out what forms of information are most useful to older people seeking to make sound financial decisions—an issue that could soon have a greater social impact than ever before. "Huge demographic changes are taking place all over the world," says Gregory Samanez Larkin, a postdoctoral researcher at Vanderbilt University and codirector of the Scientific Research Network on Decision Neuroscience and Aging, a multidisciplinary, multi-center effort funded by the National Institute on Aging. "Very soon there will be a much larger percentage of people over age 65, and that has economic implications." Financial regulatory agencies are interested in the research, says Larkin, and are funding neuroscientists as they seek ways to help older people make better investment decisions. "The natural idea is that older people are more risk-averse, but they are not uniformly more risk-averse. In some cases, they are more risk-seeking," says Scott Huettel, codirector of the Center for Neuroeconomic Studies at Duke University. © 2010 MIT Technology Review

Keyword: Development of the Brain; Attention
Link ID: 14799 - Posted: 12.18.2010

by Jennifer Viegas Female red squirrels are so promiscuous that they sometimes mate with up to 14 males in a single day, new research finds. Previously it was thought that genetics might drive female squirrels to mate like crazy on the single day each year that they go into heat. As it turns out, genes have nothing to do with it. When opportunity knocks, the not-so-picky females usually don't refuse. "Their behavior is overwhelmingly influenced by opportunity," said Eryn McFarlane, a researcher at the University of Guelph. While being a sex stud can have its perks, it can also lead to big, potentially deadly, problems. "Having multiple partners means more energy expended on mating, increased exposure to predators as well as increased potential for the spread of sexually transmitted diseases," she said. "Promiscuity also encourages harassment from male squirrels trying to coerce them into having sex." Optimal mating strategies can only evolve if genetics come into play, keeping individuals in line. Even humans have evolved genes that help to control hormones and other biochemical factors involved in our sex drives. Outside of the limited heat period, female squirrels haven't yet been able to evolve the ability to "say no" to suitors, according to McFarlane and her colleagues. Copyright © 2010 Discovery Communications, LLC.

Keyword: Sexual Behavior; Evolution
Link ID: 14798 - Posted: 12.18.2010

by Catherine de Lange GREAT ideas can feel like they come out of nowhere. Now we're a step closer to understanding where they do originate. The thinking is that areas for language and creativity compete in the brain, which might explain why some people with brain damage suddenly become artistic. Originality - or the ability to think up novel ideas that don't occur to many other people - is a key aspect of creativity. But researchers are struggling to pin down where the gift comes from. "We were amazed by the conflicting results in the literature," says Simone Shamay-Tsoory, from the University of Haifa, Israel. To better pinpoint the areas involved in creative thinking, Simone Shamay-Tsoory, and her team compared 40 people with damage to one of three distinct areas in the brain, and a group without any damage. As well as having their brains scanned, the two groups were shown 30 identical circles on a piece of paper and given 5 minutes to draw as many different pictures of meaningful objects as they could, each of which had to include at least one circle (see diagram). The volunteers were scored on their total number of responses and also on the number of statistically rare responses, deduced from earlier experiments on healthy volunteers. The test measures "divergent thinking" - the ability to generate new ideas that give different solutions to a particular problem. © Copyright Reed Business Information Ltd.

Keyword: Laterality; Language
Link ID: 14797 - Posted: 12.18.2010

by Cassandra Willyard "SM" is a bit of an emotional anomaly. The 44-year-old mother, given those initials to preserve her anonymity, isn't scared of snakes. She doesn't shriek when she sees a scary movie. Even haunted houses don't give her chills. SM is pretty much fearless—and now scientists think they've figured out why. The study's lead authors met SM, who has a rare genetic condition called Urbach-Wiethe disease, more than 2 decades ago. As a result of her illness, she has "two perfectly symmetrical black holes" where her amygdala should be, says Justin Feinstein, a graduate student in clinical psychology at the University of Iowa in Iowa City. The amygdala is a pair of almond-shaped clusters of neurons in the brain that play a role in fear and anxiety. And indeed, when the researchers examined SM, they found that she could not recognize fear on others' faces. In the new study, the researchers—who now included Feinstein—tested whether SM could experience fear. They took her to a pet store filled with snakes and spiders, showed her clips from horror films (including The Silence of the Lambs and The Shining), and brought her to the annual haunted house at the Waverly Hills Sanatorium in Louisville, Kentucky, a notoriously scary place. In each situation, SM failed to act fearful. Instead, she seemed excited and curious. In the pet store, for example, she held a snake and rubbed its scales despite telling the researchers that she "hates" snakes. In the haunted house, SM led the way, smiling and laughing. SM didn't report feeling scared. Throughout each experience, the researchers asked her to rate her fear on a scale of 1 to 10. In each case, she selected low values, 2 or lower. But SM isn't an unfeeling robot. She reports experiencing other emotions—surprise, happiness, disgust—and understands that scary movies might induce fear in others. © 2010 American Association for the Advancement of Science.

Keyword: Emotions
Link ID: 14796 - Posted: 12.18.2010

They say you never escape high school. And for better or worse, science is lending some credibility to that old saw. Thanks to sophisticated imaging technology and a raft of longitudinal studies, we’re learning that the teen years are a period of crucial brain development subject to a host of environmental and genetic factors. This emerging research sheds light not only on why teenagers act they way they do, but how the experiences of adolescence—from rejection to binge drinking—can affect who we become as adults, how we handle stress, and the way we bond with others. One of the most important discoveries in this area of study, says Dr. Frances Jensen, a neuroscientist at Harvard, is that our brains are not finished maturing by adolescence, as was previously thought. Adolescent brains “are only about 80 percent of the way to maturity,” she said at the annual meeting of the Society for Neuroscience in November. It takes until the mid-20s, and possibly later, for a brain to become fully developed. An excess of gray matter (the stuff that does the processing) at the beginning of adolescence makes us particularly brilliant at learning—the reason we’re so good at picking up new languages starting in early childhood—but also particularly sensitive to the influences of our environment, both emotional and physical. Our brains’ processing centers haven’t been fully linked yet, particularly the parts responsible for helping to check our impulses and considering the long-term repercussions of our actions. “It’s like a brain that’s all revved up not knowing where it needs to go,” says Jensen. © 2010 Harman Newsweek LLC

Keyword: Development of the Brain; Emotions
Link ID: 14795 - Posted: 12.18.2010

By MALCOLM RITTER, NEW YORK – Meet SM, a 44-year-old woman who literally knows no fear. She's not afraid to handle snakes. She's not afraid of the "The Blair Witch Project," "The Shining," or "Arachnophobia." When she visited a haunted house, it was a monster who was afraid of her. SM isn't some cold-blooded psychopath or a hero with a tight rein on her emotions. She's an ordinary mother of three with a specific psychological impairment, the result of a very rare genetic disease that damaged a brain structure called the amygdala (uh-MIG'-duh-luh). Her case shows that the amygdala plays a key role in making people feel afraid in threatening situations, researchers say. Her life history also shows that living without fear can be dangerous, they said. A study of her fearlessness was published online Thursday in the journal Current Biology by University of Iowa researcher Justin Feinstein and colleagues. As is typical, the paper identifies her only as "SM." Feinstein declined to make SM available for an interview with The Associated Press, citing laboratory policy about confidentiality. An expert unconnected with the study cautioned against drawing conclusions about the amygdala, noting that her own work with a similarly brain-damaged woman found no such impairment. But another expert said the new finding made sense. © 2010 The Associated Press.

Keyword: Emotions
Link ID: 14794 - Posted: 12.18.2010

By Helen Briggs Fighter pilots may owe their ability to perform under pressure to the way their brains are wired-up, scans suggest. The study found differences in the white matter and connections of the brain's right hemisphere, compared with healthy volunteers who were not pilots. It is not clear whether pilots are born like that, or develop the differences as a result of their training. The research by University College London (UCL) is published in the Journal of Neuroscience. Royal Air Force fighter pilots are trained to fly at supersonic speeds at low altitude, requiring fine control with very little room for error. The discipline is considered to be at the limits of human cognitive performance, prompting doctors at UCL to study their brain function. The research team looked at how 11 front-line RAF Tornado fighter pilots performed in two standard visual cognitive tests to assess their powers of thought. Their test scores were compared with healthy people of the same age and sex who had no experience of piloting aircraft. The subjects were also given MRI scans to look at the structure of their brains. BBC © MMX

Keyword: Attention; Brain imaging
Link ID: 14793 - Posted: 12.16.2010

By Jason Palmer The free will that humans enjoy is similar to that exercised by animals as simple as flies, a scientist has said. The idea may simply require "free will" to be redefined, but tests show that animal behaviour is neither completely constrained nor completely free. The paper, in Proceedings of the Royal Society B, suggests animals always have a range of options available to them. "Choices" actually fit a complex probability but, at least in humans, are perceived as conscious decisions. The idea tackles one of history's great philosophical debates, and Bjoern Brembs of the Berlin Free University brings the latest thinking from neurobiology to bear on the question. What has been long established is that "deterministic behaviour" - the idea that an animal poked in just such a way will react with the same response every time - is not a complete description of behaviour. "Even the simple animals are not the predictable automatons that they are often portrayed to be," Dr Brembs told BBC News. However, the absence of determinism does not suggest completely random behaviour either. BBC © MMX

Keyword: Attention
Link ID: 14792 - Posted: 12.16.2010

By Jason Castro The voicemail rant. The overheard insult. The lonely moral slip when your chips were down. Despite their sting, these unkind memories eventually slacken their grip. We manage, move on, shrug it off, and go about the business of filling our heads with thoughts of a better tomorrow. But for war veterans and victims of violent crime, the persistence of traumatic memories can mean a life of disability. Even when emotional demons are quieted with therapy or drugs, they are prone to return. A whispered reminder in an unfamiliar setting is sometimes all it takes. Frustrated with these grim facts, scientists have been looking for biologically based therapies that may some day help troubled minds forget debilitating fears. The most recent of these studies, by Drs. Roger Clem and Richard Huganir at Johns Hopkins, gives a spectacularly detailed view of how fear is learned, and points out fear’s Achilles Heel. The very molecular machinery that implants fear in the brain may also hold the key to its undoing. We already understand a good deal about how specific fears come to be thanks to classical neuroscience experiments, many done by Joseph LeDoux and his colleagues at New York University. Fear lives in a small almond-shaped pair of brain structures, called the amgydalae, that control your body’s panic buttons. Each amygdala receives two basic kinds of inputs: streaming images from our senses, as well as incoming alerts conveying threats, danger, or pain. When one of these alert signals – say the pain of a shock or cut – is detected together with a sensory image (such as a particular face or the sound of a gunshot), neurons in the amygdala take notice. © 2010 Scientific American,

Keyword: Emotions; Learning & Memory
Link ID: 14791 - Posted: 12.16.2010

By Ferris Jabr Your brain is electric. Tiny impulses constantly race among billions of interconnected neurons, generating an electric field that surrounds the brain like an invisible cloud. A new study published online July 15 in Neuron suggests that the brain’s electric field is not a passive by-product of its neural activity, as scientists once thought. The field may actively help regulate how the brain functions, especially during deep sleep. Although scientists have long known that external sources of electricity (such as electroshock therapy) can alter brain function, this is the first direct evidence that the brain’s native electric field changes the way the brain behaves. In the study, Yale University neurobiologists David McCormick and Flavio Fröhlich surrounded a still-living slice of ferret brain tissue with an electric field that mimicked the field an intact ferret brain produces during slow-wave sleep. The applied field amplified and synchronized the existing neural activity in the brain slice. These results indicate that the electric field generated by the brain facilitates the same neural firing that created the field in the first place, just as the cloud of enthusiasm that envelops a cheering crowd at a sports stadium encourages the crowd to keep cheering. In other words, the brain’s electric field is not a by-product; it is a feedback loop. Although researchers knew that periods of highly synchronized neural activity (such as that of deep sleep) are crucial for maintaining normal brain function, exactly how these stable phases are coordinated—and why they go awry in dis­orders such as epilepsy—was never clear. The new study indicates scientists may find some answers in the surprisingly active role of the brain’s electric field. © 2010 Scientific American,

Keyword: Sleep
Link ID: 14790 - Posted: 12.16.2010

by Greg Miller Testimony on the brain activity of a convicted murderer may have saved him from the death penalty. Earlier this month, a jury in Miami rejected the death penalty and chose life in prison for Grady Nelson, who in 2005 stabbed his wife 61 times, killing her, and stabbed and raped her 11-year-old, mentally handicapped daughter. A report in The Miami Herald last weekend suggests that measurements of Nelson's brain activity may have influenced some members of the jury, who viewed the results as evidence of a brain injury that would partially explain his behavior. But some scientists are critical of the way this technology was used in the case. During the sentencing phase of the trial, the court heard testimony from Robert Thatcher, a neuroscientist and president of by Applied Neuroscience Inc. of St. Petersburg, Florida. Thatcher's company examined Nelson using a method called quantitative electroencephalography (QEEG). As in standard EEG, technicians place electrodes on the skull to record electrical activity in the brain. In QEEG, a computer program analyzes these recordings to locate regions of abnormal activity. In Nelson's case, there was an obvious abnormality in the left frontal lobe, Thatcher says. Thatcher also testified that Nelson exhibited "sharp waves" originating from this region. These large spikes in the EEG trace are typically seen in people with epilepsy. Grady is not epileptic, but he does have a history of at least three traumatic brain injuries, Thatcher said yesterday in an interview. © 2010 American Association for the Advancement of Science.

Keyword: Aggression; Epilepsy
Link ID: 14789 - Posted: 12.16.2010

by Virginia Morell As any dog owner knows, dogs pay close attention to each other's growls—and with good reason. A new study reveals that dogs can tell another canine's size simply by listening to its growl. The size information is so accurate that a dog hearing a growl can match the sound to a photograph of the growler—a complex cognitive talent previously seen only in primates. In a previous study, Péter Pongrácz, an ethologist at Eötvös Loránd University in Hungary, and colleagues showed that dogs use a specific growl ("this bone is mine") when guarding a tasty bone. The growl always causes a listening dog to stop in its tracks. In their new study, the scientists tested the responses of dogs seated next to their owners, so that the animals felt comfortable in the lab. Twenty-four of the 96 dogs were shown images of two dogs projected onto a screen in front of them (see picture). One image showed a small dog less than 52 centimeters tall; the other image was of the same dog but projected as being taller than 60 cm (a 30% increase in size). The other dogs were shown control images, either of large and small triangles or of the silhouettes of large and small cats. The researchers then played recorded food-guarding growls—from either a large or a small dog—on a speaker placed between the two projected images. The scientists filmed the dogs, recording where the canines looked as they listened to the growls. © 2010 American Association for the Advancement of Science.

Keyword: Aggression; Animal Communication
Link ID: 14788 - Posted: 12.16.2010

By PAM BELLUCK Congress has voted unanimously to create, for the first time, a national plan to combat Alzheimer’s disease with the same intensity as the attacks on AIDS and cancer. The bill, expected to be signed by President Obama, would establish a National Alzheimer’s Project within the Department of Health and Human Services, to coordinate the country’s approach to research, treatment and caregiving. Its goal, the legislation says, is to “accelerate the development of treatments that would prevent, halt or reverse the course of Alzheimer’s” and “improve the early diagnosis of Alzheimer’s disease and coordination of the care and treatment of citizens with Alzheimer’s.” The project would include an advisory council of representatives from agencies like the Centers for Disease Control and Prevention, the National Institutes of Health, the Department of Veterans Affairs, the Food and Drug Administration, the Indian Health Service and the Centers for Medicare and Medicaid Services. Scientific experts, health care providers and people caring for relatives with Alzheimer’s would also be included. “If you go to war, you have planning, planning, planning,” said Representative Christopher H. Smith, Republican of New Jersey, who co-sponsored the bill. “Well, this is a war on a dreaded disease. We need to bring all the disparate elements together for the greatest possible result.” Copyright 2010 The New York Times Company

Keyword: Alzheimers
Link ID: 14787 - Posted: 12.16.2010

By Laura Sanders Researchers are closer to understanding how a bong packed with leaves of Salvia divinorum gave Smiley Miley the giggles. Although shamans in Mexico have been chewing the leaves of the hardy mint relative for centuries (and without any prompting from an infamous YouTube video of Miley Cyrus smoking it), little is known about what the plant’s psychoactive substance, salvinorin A, actually does to humans — despite its increasing popularity as a recreational drug. A new study provides some data: The hallucinogen kicks off an unusually intense and short-lasting high, with no obvious ill effects, researchers report in an upcoming Drug and Alcohol Dependence paper. “This is a landmark paper because it’s the first paper in which authentic salvinorin A was administered to human volunteers under controlled conditions, and it was shown to be hallucinogenic,” says psychiatrist and pharmacologist Bryan Roth of the University of North Carolina at Chapel Hill, who was not involved in the research. “All we had before were anecdotal reports, where people had bought salvia extract from their local smoke shop.” While the study is small and can’t vouch for the safety of salvia, the results lend some hard science to the current legislative fray around the substance, which is criminalized in some states but not regulated federally. © Society for Science & the Public 2000 - 2010

Keyword: Drug Abuse
Link ID: 14786 - Posted: 12.16.2010

By Tina Hesman Saey PHILADELPHIA — Scientists are learning how they might stoke the body’s fat-burning furnace by turning up a molecular thermostat. Mice lacking a protein that responds to the hunger-promoting hormone ghrelin burn more energy in their brown fat than other mice, Yuxiang Sun of Baylor College of Medicine in Houston reported December 13 at the American Society for Cell Biology’s annual meeting. This revved-up brown fat helps keep mice lean and energetic into middle age. The finding could eventually lead to a way to help people fight obesity. Brown fat burns energy instead of just storing it the way white fat does. This metabolically active fat is important in helping rodents and other animals maintain their body temperature. Recently researchers learned that adult humans have brown fat, and that the amount of energy burned by brown fat decreases with age and weight. The discovery has spurred interest in learning how to turn brown fat on. Sun and her colleagues didn’t start out trying to rev up brown fat. Because the hormone ghrelin has been shown to make animals eat more, the researchers reasoned that blocking the molecule’s activity might reduce appetite and help animals and people lose weight. Sun and her colleagues genetically engineered mice to completely lack either ghrelin or the ghrelin receptor, a protein that interacts with ghrelin and sets off a series of biological reactions in cells that leads to the hormone’s effect. © Society for Science & the Public 2000 - 2010

Keyword: Obesity; Genes & Behavior
Link ID: 14785 - Posted: 12.16.2010