By Dave Mosher If you can't remember where you left the car keys, take comfort in a new study that suggests the brain's memory capacity may be far lower than once thought. About 100 billion neurons, or brain cells, make up the average adult's brain, but the computer-based discovery shows our memory isn't based simply on neuron numbers. Instead, the limited amount of connections a neuron can make to other neurons may cut memory capacity. "People have suspected this for a long time, but we've shown it's possible for the first time in realistic memory networks," said study co-author Peter Latham, a neuroscientist at University College London. Latham and his colleague's findings are detailed online in the journal PLoS Computational Biology. Neurons produce electrical signals that travel through each cell's 10,000-or-so "cables" of nerve tissue, each connected to another neuron to form a "network" of communicating cells. Latham explained, however, that neurons often produce random, meaningless signals that create noise in neuron-to-neuron speech. "Thankfully, the vast amount of noise averages out so our brain can do something useful," Latham said, such as interpret the signals carrying the memory of where you last placed your car keys. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Learning & Memory
Link ID: 10741 - Posted: 06.24.2010

By ALAN SCHWARZ To Kelby Jasmon, there was only one answer. The question: If he received yet another concussion this football season, while playing offensive and defensive line for his high school in Springfield, Ill., would he tell a coach or trainer? Jasmon, with his battering-ram, freshly buzz-cut head and eyes that danced with impending glory, immediately answered: “No chance. It’s not dangerous to play with a concussion. You’ve got to sacrifice for the sake of the team. The only way I come out is on a stretcher.” Jasmon, a senior with three concussions on his résumé, looked at two teammates for support and unity. They said the same thing with the same certainty: They did not quite know what a concussion was, and would never tell their coaches if they believed they had sustained one. Matt Selvaggio, who plays with Jasmon on both lines, said: “Our coaches would take us out in a second. So why would we tell them?” Many of the 1.2 million teenagers who play high school football are chanting similar war whoops as they strap on their helmets. They either do not know what a concussion is or they simply do not care. Their code of silence, bred by football’s gladiator culture, allows them to play on and sometimes be hurt much worse — sometimes fatally. Copyright 2007 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 10740 - Posted: 06.24.2010

By PETER JARET Sometimes, the cure is worse than the disease. Sometimes, the cure is the disease. Four percent of Americans suffer headaches daily, and scientists have suspected culprits as diverse as undiagnosed jaw disorders, genetic susceptibility and stress. But according to recent research, a sizeable and growing number of headaches are being caused by the very medications taken to alleviate them — and the problem is far more common than scientists had realized. Half of chronic migraines, and as many as 25 percent of all headaches, are actually “rebound” episodes triggered by the overuse of common pain medications. Both prescription and over-the-counter drugs may be to blame. Patients begin by popping too many pills to deal with a migraine or a simple tension-type headache. When the medications stop, another headache follows, similar to a hangover. Sufferers race again to the medicine cabinet, and before long they are locked in a cycle of headaches and overmedication. At any given time, more than three million Americans are suffering from headaches they are inflicting on themselves, according to Dr. Stephen D. Silberstein, a professor of neurology and director of the Jefferson Headache Center at Thomas Jefferson University in Philadelphia. “If a patient’s headaches have grown markedly worse or more frequent, the problem is almost always medication overuse,” Dr. Silberstein said. Copyright 2007 The New York Times Company

Keyword: Pain & Touch
Link ID: 10739 - Posted: 06.24.2010

By Gisela Telis If, as Roy Orbison sang, "Only the lonely" know how you feel tonight, you may need a doctor. A new study shows that loneliness may change how certain genes in the body work, leaving chronically lonely people with less effective immune systems and lower defenses against disease. The results, if confirmed, could enable doctors to better prevent those ills for which the lonely are at greater risk, such as heart disease, infection, age-related dementia, and certain types of cancer. Everyone feels lonely from time to time, but some people have it much worse. These individuals consistently feel lonely for years, often despite having friends and family. Researchers have long known that such chronically lonely people are less healthy. They suspected cortisol, a hormone that regulates the body's response to stressful or threatening situations, was to blame, because it's found in higher levels in people who feel isolated. But the mechanism remained a mystery, and one nagging question persisted: If inflammation drives most loneliness-linked diseases, how can cortisol, with its anti-inflammatory properties, be the culprit? Steve Cole, a genomics researcher at the University of California, Los Angeles (UCLA), and colleagues tracked a group of 153 people in their 50s and 60s, in hopes they'd provide an answer. The team ranked the volunteers using the UCLA Loneliness Scale, a test that measures a subject's loneliness by their responses to statements such as "I'm alone in the world" and "There's no one I can count on," regardless of how many people they know or spend time with. The researchers then studied DNA from the white blood cells of eight people who scored in the top 15th percentile of loneliness and six who scored in the bottom 15th percentile. © 2007 American Association for the Advancement of Science.

Keyword: Genes & Behavior; Neuroimmunology
Link ID: 10738 - Posted: 06.24.2010

By Will Dunham WASHINGTON (Reuters) - An experimental body cooling treatment used on an injured National Football League player offers promise for preventing paralysis in people who sustain severe spinal cord injuries, experts said on Thursday. But the value of "modest hypothermia," the treatment used on Kevin Everett of the Buffalo Bills after he was injured in a game on Sunday, remains controversial among some doctors who want to see more evidence it helps those patients. The idea behind the treatment is to lower the body temperature -- but not by too much in order to avoid other complications -- to restrict damage to the spinal cord. "Right now, it's not mainstream medicine," said Dr. Barth Green, co-founder of the Miami Project to Cure Paralysis at the University of Miami, who has helped develop the treatment. "But it's an amazing technique," said Green, who has consulted with Everett's doctors. "I think it's very likely he's going to walk again. Nothing is guaranteed in life. But every day he's getting better." Everett, 25, sustained the injury tackling an opposing player in an apparently routine play. He is being treated at Millard Fillmore Gates Circle Hospital in Buffalo, New York. © 1996-2007 Scientific American, Inc.

Keyword: Brain Injury/Concussion; Regeneration
Link ID: 10737 - Posted: 06.24.2010

By Nikhil Swaminathan A population of nerve cells crucial for proper brain wiring may serve a completely different function in adult and fetal brains, according to a new study in The Journal of Neuroscience. Previously, most of these cells, known as subplate neurons, were thought to die off shortly after development, leaving behind 10 to 20 percent of the original fleet as nonfunctional remnants. Several tests conducted by a pair of researchers at the Baylor College of Medicine in Houston, however, revealed that the leftover neurons are not just vestiges but electrically active messengers that can send and receive signals to and from any of the six layers of the cerebral cortex (the brain's outermost layer, which is essentially the brain's central processing unit). The function of subplate neurons have yet to be determined, but the study's senior author, Michael Friedlander, chair of Baylor's department of neuroscience, speculates that it is possible they can be coaxed to reprise their fetal role of developing proper circuits between neurons to possibly rewire and repair the cortex after a brain injury. During development, subplate neurons serve as bridges and scaffolding while connections are established between neurons in the cortex and other cell populations in the thalamus, a midbrain structure responsible for sensory processing, motor control and consciousness. © 1996-2007 Scientific American, Inc.

Keyword: Development of the Brain; Stem Cells
Link ID: 10736 - Posted: 06.24.2010

Bruce Bower In October 2004, Swedish neuroscientist Bjorn Merker packed up his video camera and joined five families for a 1-week get-together in Florida that featured several visits to the garden of childhood delights known as Disney World. For Merker, though, the trip wasn't a vacation. With the parents' permission, he came to observe and document the behavior of one child in each family who had been born missing roughly 80 percent of his or her brain. These children, 1 to 5 years old at the time of their Disney adventure, had suffered strokes as fetuses or had experienced other medical problems shortly before or after birth that destroyed nearly all of the brain's outer layer, or cortex. In this rare condition, called hydranencephaly, cerebrospinal fluid fills the gaping hole within the child's head. Such youngsters often die in the first year of life as a result of seizures, cerebral palsy, lung abnormalities, and a variety of other physical ailments. With proper medication and the installation of shunts to drain fluid from the braincase, however, some individuals live 20 years or more. Neurologists typically regard hydranencephaly as an anatomical sentence to a lifelong "vegetative state." Such children supposedly validate a brutally simple equation: Little or no cortex equals no awareness of any kind. ©2007 Science Service.

Keyword: Development of the Brain
Link ID: 10735 - Posted: 06.24.2010

By Patrick Enright It was the mid-'60s, and Ron Wilson was a college sophomore with one acting class under his belt. He was starring in Edward Albee's two-man play "The Zoo Story," and after an uneventful opening night, he was preparing to go onstage for his second performance. But as soon as his feet touched the boards, he couldn't remember a single line. "I didn't know what to do, so I just started moving," he remembers. "The poor actor onstage with me almost died." After a while, he began to remember some of the lines from a five-page monologue his character was to deliver, and he started reciting them … though not in order. He'd pick up a line somewhere in the middle of the speech and go backward and forward, sometimes returning to the beginning. Over the course of the night, he estimates that he delivered the same monologue five times. At one point, he remembered the switchblade knife, a stage prop, in his pocket. "I knew I wanted to end it right there!" he jokes. Wilson, now director of the Case-Cleveland Playhouse Master of Fine Arts Acting Program in Ohio, is far from alone — the list of successful performers who have suffered from stage fright is long and illustrious, including Laurence Olivier, Barbra Streisand, Carly Simon, Rod Stewart and opera star Renee Fleming, to name just a few. And the fear of public speaking, a more common manifestation of stage fright, plagues 40 percent of American adults, according to a 2001 Gallup poll. © 2007 MSNBC Interactive

Keyword: Stress
Link ID: 10734 - Posted: 06.24.2010

By BRENT BOWERS As his mother tells it, Cade Larson was a lively 15-month-old who loved playing peekaboo and chase with other children and was quickly adding to his vocabulary of more than 50 words, including “fish,” “bowl” and “shoe.” But then, said his mother, Jennifer VanDerHorst-Larson, Cade got vaccinations for measles, mumps and rubella, influenza and chicken pox on Oct. 15, 2001. He wailed for a few moments, then slumped into a deep sleep that lasted 14 hours. When he woke up, she said, he was a different child. “He stopped looking at me,” Ms. VanDerHorst-Larson said. “He had lost his speech.” She believes he had a huge seizure that resulted in brain damage. In a heartbeat, her mission became healing her son. In that, she failed. On Valentine’s Day 2002, her school district told her that Cade had the severest case of autism it had ever seen. “This is my only child,” she said. “I can’t describe the pain.” The idea that vaccines cause autism has been widely rejected by mainstream scientists, though some doctors are investigating it and many parents of autistic children remain convinced there is a link. But Ms. VanDerHorst-Larson, 35, had a resource for fighting back that many parents do not: She was an entrepreneur. Copyright 2007 The New York Times Company

Keyword: Autism
Link ID: 10733 - Posted: 06.24.2010

By Melissa Dahl Is he gay or straight? At a glance, the key to telling might be in the way he walks. A swing of the hips or a swaggered shoulder is enough for many casual observers to identify a man’s sexual orientation, according to a study published in the September issue of the Journal of Personality and Social Psychology. Observers were only able to accurately guess the sexual orientation of men; with women, their guesses didn’t exceed chance. But what’s most interesting to researchers is understanding how that snap judgment can unleash a series of stereotypes — even from the most liberal-minded. “This is important for the understanding of perception and feelings of assumptions and bias,” says lead author Kerri Johnson, an assistant professor of communications at the University of California, Los Angeles. “Once you know an individual’s sexual orientation, every else that happens is seen through that lens.” Johnson and her colleagues attached motion sensors, like those used in the movie industry, to the hips and shoulders of eight volunteers – four men and four women, half of whom were gay. The motion sensors captured the only movements of the walkers, masking details such as clothing or hairstyles. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Sexual Behavior
Link ID: 10732 - Posted: 06.24.2010

SUNY Downstate Medical Center neurologist Todd Sacktor compares memory to a glue that connects our consciousness. "It's like the essence of what keeps our soul together, our character together," he says. Despite the importance of this powerful, intangible wonder called memory, the mechanics of it still baffles scientists. And Sacktor recently peeled off one layer of the mystery. Sacktor and his collaborators at the Weizmann Institute of Science in Israel discovered that they could wipe out the long-term memory of rats with a single injection. "We went out even weeks and weeks later, and still the memory was erased, just like that," says Sacktor, snapping his fingers. The researchers trained rats to avoid certain tastes in drinks that the animals learned to associate with an upset stomach. Weeks later, they gave the rats an experimental drug called "ZIP" and, within minutes, the animals forgot which drinks to avoid. As Sacktor and his colleagues wrote in the journal "Science," the drug works by blocking a molecule called PKM zeta, which seems crucial to preserving memories. Sacktor says that this molecule works as a continuous memory motor when nerve cells, or neurons, in the brain communicate with each other as memories are formed. It triggers twice the number of receptors from one neuron to accept signals from another. But if that motor gets jammed, the number of receptors gets reduced again and the memories disappear. © ScienCentral, 2000-2007.

Keyword: Learning & Memory
Link ID: 10731 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — A big, warm hug works wonders, even in the monkey world. Female spider monkeys without infants, it seems, will hug mother monkeys in exchange for permission to kiss, sniff and touch their babies. The discovery, which will be outlined in an upcoming issue of Animal Behavior, not only shows how much primates, especially females, value infants, but it also reveals that an embrace conveys good intentions and provides comfort in primate species other than humans. "An embrace is defined as one monkey approaching another monkey and wrapping their arms around them, in very much the same way as humans do, with one arm wrapped around the neck and the other around the waist," lead author Kathy Slater told Discovery News. Slater, a researcher in the Department of Psychology at the University of Chester, added that the embrace is often accompanied by a "kiss on the cheek" and a "pectoral sniff," when one monkey moves its head next to the other monkey's chest scent glands to get a whiff. She said both males and females tend to hug when they haven't seen each other for a while. Males will also sometimes hug each other in front of females "to reduce tension and prevent aggression" in a situation that can foster competition. © 2007 Discovery Communications

Keyword: Sexual Behavior
Link ID: 10730 - Posted: 06.24.2010

Heidi Ledford Knocking out a single gene nearly doubles the lifespan of mice with the animal model of Lou Gehrig's disease, suggesting that the gene may one day become a target for therapies in humans. Lou Gehrig's disease, otherwise known as amyotrophic lateral sclerosis (ALS), is a neurodegenerative disease that gradually erodes motor control. Death usually follows within three to five years of diagnosis. There is no cure, and the only drug available that slows progression of the disease, riluzole, prolongs survival only by a few months. Mice develop ALS-like symptoms when they have a mutation in a gene called SOD1 — a mutation that causes about 1-2% of human ALS cases. Research using these animal models has suggested that chemically reactive forms of oxygen that can damage cells also contribute to the disease. Several proteins present in the bodies of mice and people are known to generate reactive oxygen species as part of their normal function in cell signalling and inflammation. So John Engelhardt and his colleagues at the University of Iowa in Iowa City decided to look closely at two of these — Nox1 and Nox2 — to see whether turning down the amount of such proteins could slow the progression of ALS symptoms. It did — dramatically. The team found that ALS mice lacking the gene that creates Nox2 produced fewer reactive oxygen species and lived on average for 229 days — 97 days longer than those who had normal levels of Nox21. ©2007 Nature Publishing Group

Keyword: ALS-Lou Gehrig's Disease
Link ID: 10729 - Posted: 06.24.2010

Memory loss. It's right up there with other signs of aging, such as wrinkles, hearing loss, and bifocals. While you might dismiss it as a "senior's moment," your brain has actually been going downhill since your early 30s. Our brains are naturally "rusting on the inside," as one expert puts it, but you can slow the process. You can eat for brain longevity and actually exercise this important organ. What is brain aging? Generally, brain aging is believed to be the gradual deterioration of the brain and its related systems. Historically,the process of aging has been largely ignored.Dementia, memory loss and mood changes were expected of the elderly.But over the last three decades, this view has undergone a transformation.Scientists now understand far more about the normal aging process and the causes of age-related conditions such as Alzheimer's disease, Parkinson's disease, and stroke. And with one in five Canadians reaching the age of 65 by 2026, health-care and research priorities areshifting to cope with the unique concerns of the aged population. © CBC 2007

Keyword: Alzheimers
Link ID: 10728 - Posted: 06.24.2010

By SALLY SATEL EARLIER this summer, the American Psychiatric Association announced that a 27-member panel will update its official diagnostic handbook, the Diagnostic and Statistical Manual of Mental Disorders. The fifth edition, which is scheduled to come out in 2012, is likely to add new mental illnesses and refine some existing ones. High on the agenda will be the controversial diagnosis of childhood bipolar disorder. Recent data show that office visits by children and adolescents treated for the condition jumped 40-fold from 1994 to 2003. We still don’t know how much of this increase represents long-overdue care of mentally ill youth and how much comes from facile labeling of youngsters who are merely irritable and moody. Part of the confusion stems from the lack of a discrete definition of juvenile bipolar illness in the diagnostic manual. But there is a deeper problem: despite the great progress being made in neuroscience, we still don’t have a clear picture of the brain mechanisms underlying bipolar illness — or most other mental illnesses. For perspective, we must return to 1980, when the revolutionary third edition of the handbook, the D.S.M. III, was published. In a radical break from earlier editions, which had been based largely on psychoanalytic principles of unconscious conflict and stunted sexual development, the D.S.M. III categorized illnesses based on symptoms. A patient was said to have a condition if he or she had a certain number of the classic symptoms for a certain period of time. This approach promoted “inter-rater reliability” — the odds that two examiners would agree on what diagnosis to assign a patient. Copyright 2007 The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 10727 - Posted: 06.24.2010

By GINA KOLATA WHEN Jennifer Davis, my partner for long runs, was in college about 15 years ago, she had a real problem staying awake in her classes. The reason, she said, were those long, grueling workouts with the Dartmouth crew early in the day. Accepting Insomnia, Not Defeat (September 13, 2007) “Those are the only memories I have of totally falling asleep in lectures,” said Ms. Davis, a physical chemist living in Montgomery, N.J. “My notes from biology consist largely of squiggly lines meandering down the page of my notebook.” It’s one of the mysteries of sleep: Why is it that mild exercise can be invigorating, but strenuous endurance exercise — whether it’s crew practice, long runs as training for a marathon or juggling back-to-back workouts to prepare for a triathlon — makes people groggy? Elite marathoners know that hunger for sleep all too well. Deena Kastor, who won the London Marathon last year and set an American record, said she sleeps 10 hours at night and takes a two-hour nap every afternoon. Steven Spence, a marathoner who won a bronze medal at the 1991 world championships in Tokyo, had the same sleep habits when he was training. “I would be sleeping about half of my life,” Mr. Spence said. Copyright 2007 The New York Times Company

Keyword: Sleep
Link ID: 10726 - Posted: 06.24.2010

By Michael Balter A new study of ancient reptile fossils has pushed back the date for the earliest known ear by 60 million years and generated a new hypothesis of why hearing evolved in the first place. An ear capable of hearing airborne sounds evolved independently at least six times among terrestrial vertebrate groups, including mammals, lizards, frogs, turtles, crocodiles, and birds. Yet although these ears may differ in some details, they all share certain features: an eardrumlike membrane to capture sound vibrations and small bones--such as the stapes--to transmit the sounds to the inner ear. Based on the fossil record, the earliest known ears of this type date to 200 million years ago or later. To further explore the evolutionary roots of terrestrial vertebrate hearing, paleobiologists Johannes Müller and Linda Tsuji of Humboldt University in Berlin, Germany, examined several dozen specimens of early reptiles that have been found since the 1930s in the Mezen River Basin of central Russia. The fossils, which date to about 260 million years ago, had previously received only limited study. The researchers were able to identify six apparently closely related species, all of which showed clear evidence of large, eardrumlike structures covering much of their cheeks. In the better preserved specimens, inner ear bones similar to those of modern ears were found, including a stapes. Moreover, Müller and Tsuji found, the relative sizes of the eardrum and the part of the stapes that communicates with the inner ear were similar to those in modern terrestrial vertebrates, a key test that this ancient ear had the acoustic properties necessary for hearing airborne sounds. The findings are published online today in PLoS One. © 2007 American Association for the Advancement of Science.

Keyword: Hearing; Evolution
Link ID: 10725 - Posted: 06.24.2010

The medication tamoxifen, best known as a treatment for breast cancer, dramatically reduces symptoms of the manic phase of bipolar disorder more quickly than many standard medications for the mental illness, a new study shows. Researchers at the National Institutes of Health's National Institute of Mental Health (NIMH) who conducted the study also explained how: Tamoxifen blocks an enzyme called protein kinase C (PKC) that regulates activities in brain cells. The enzyme is thought to be over-active during the manic phase of bipolar disorder. By pointing to PKC as a target for new medications, the study raises the possibility of developing faster-acting treatments for the manic phase of the illness. Current medications for the manic phase generally take more than a week to begin working, and not everyone responds to them. Tamoxifen itself might not become a treatment of choice, though, because it also blocks estrogen — the property that makes it useful as a treatment for breast cancer — and because it may cause endometrial cancer if taken over long periods of time. Currently, tamoxifen is approved by the Food and Drug Administration for treatment of some kinds of cancer and infertility, for example. It was used experimentally in this study because it both blocks PKC and is able to enter the brain. Results of the study were published online in the September issue of Bipolar Disorders by Husseini K. Manji, MD, Carlos A. Zarate Jr., MD, and colleagues. Almost 6 million American adults have bipolar disorder, whose symptoms can be disabling. They include profound mood swings, from depression to vastly overblown excitement, energy, and elation, often accompanied by severe irritability. Children also can develop the illness.

Keyword: Schizophrenia; Hormones & Behavior
Link ID: 10724 - Posted: 06.24.2010

Michael Hopkin Whatever it was that sealed the fate of the Neanderthals, it looks unlikely to have been climate change. That is the verdict of a new study that used climate records from Venezuela to deduce what happened at the Neanderthals' last stand at the southern tip of Europe. The research suggests that a switch to a cold, dry climate was probably not the telling factor in the demise of the Neanderthals, because of all the probable dates for their extinction, most do not lie near major cold events in the climate record. Neanderthals (Homo neanderthalensis) lived in Europe until around 30,000 years ago — not long after Homo sapiens arrived on the scene 40,000 years ago. The Neanderthals are thought to have lasted longest in the region around Gibraltar, off the southern tip of Spain. "There are different factors that have been invoked to explain the Neanderthal extinction," says Chronis Tzedakis of the University of Leeds, UK, who led the new research. "Clearly the appearance of anatomically modern humans is the prime suspect, but given that the extinction happened during the last glacial period, when climate was changing, what we know is that the climate was extremely unstable at that time." The main problem with testing the different theories comes from the difficulty in dating accurately the age of Neanderthal fossils and tools to compare their ages with records of past climate. ©2007 Nature Publishing Group

Keyword: Evolution
Link ID: 10723 - Posted: 06.24.2010

CBC News Ask any devotee about the benefits conferred by alternative therapies such as yoga, tai chi and hypnosis, and the they'll tell you the list is lengthy. After a recent review by researchers at the University of Pittsburgh, chronic pain management can be added to the list. According to the study, chronic non-malignant pain occurs in up to 50 per cent of older adults. Researchers reviewed 20 clinical trials involving eight mind-body therapies for adults who suffered from chronic, non-malignant pain, to assess their feasibility, effectiveness in pain management and safety. The findings are published in Volume 8 of the journal Pain Medicine. The therapies reviewed included biofeedback (learning to control body functions) , progressive muscle relaxation (tensing and releasing muscles), meditation, guided imagery (visualization techniques), hypnosis, tai chi chuan (a Chinese martial art consisting of sequences of very slow, controlled movements) qi gong (movements that include elements of meditation, relaxation and physical movement), and yoga. © CBC 2007

Keyword: Pain & Touch
Link ID: 10722 - Posted: 06.24.2010