New ways of treating Parkinson's disease by stimulating the brain are to be investigated by scientists. Deep brain stimulation eases symptoms, such as tremors, by allowing sufferers to deliver electrical pulses to electrodes implanted in their brains. Researchers at St Andrews University will study what happens in the head when the electrodes are switched on. They will also look at whether other symptoms can be eased by targeting different parts of the brain. Symptoms of Parkinson's disease include tremors, difficulty moving and poor balance. Professor Philip Winn, from St Andrews University, will work with researchers in Germany, Italy, France and Scotland on the three-year, £1.17m project. He said he wanted to find answers to a range of questions. "One is to do with exactly what effect the electrical stimulation is having on the brain. Is it the case that we're stimulating activity or is it in fact the case that the stimulation we do, what the electrical pulses do, is actually to shut down activity locally where the electrode is implanted?" Prof Winn said. He said more effective treatment for Parkinson's could be developed if they could understand the effect of the stimulation. The other part of the research will consider where in the brain the electrodes should be placed. Prof Winn said: "If you put the electrode at the most commonly used site you can inhibit tremors that Parkinsonian patients have, which are very disturbing and distressing to them. "But it's thought possible that if we put electrodes at other sites we can have an affect on the posture and gait problems that patients have. (C)BBC

Keyword: Parkinsons
Link ID: 12516 - Posted: 02.03.2009

Tracking changes in the levels of a certain hormone during pregnancy may help to predict which women may suffer postpartum depression, a small study suggests. Risk factors include a history of depression, a stressful or anxious pregnancy, a lack of social support, and low self-esteem, but these explain only a portion of why some women develop postpartum depression. In Monday's online issue of Archives of General Psychiatry, researchers who studied 100 women said they found 12 out of 16 participants who had postpartum depression also had high levels of corticotropin-releasing hormone or CRH. In the study, high levels of CRH at 25 weeks gestational age helped to predict future postpartum depression or PPD in about three-fourths of women and misclassified 24 per cent, the researchers said. CRH is normally produced in tiny amounts by the brain's hypothalamus in response to stress. During pregnancy, the placenta produces much more of the hormone, which is thought to prepare a woman's body for childbirth. Levels of CRH and other hormones drop after giving birth. © CBC 2009

Keyword: Depression; Hormones & Behavior
Link ID: 12515 - Posted: 06.24.2010

Peter Aldhous, San Francisco bureau chief Among my editors in London, I'm sometimes known as the Prince of Darkness - not for any particular satanic tendencies, but because I frequently send emails when most people in my time zone in California are fast asleep. Like millions of others, I'm a chronic insomniac, so when the table of contents for the latest issue of Behavior Therapy dropped into my email inbox at 1:45 am on Sunday, I was drawn to a paper entitled Sleep Hygiene Practices of Good and Poor Sleepers in the United States: an Internet-Based Study. For the uninitiated, "sleep hygiene" has nothing to do with the cleanliness of your bedroom, but instead refers to behaviours that influence the quality of your sleep. The problem is that previous research has yielded conflicting results as to which behaviours, exactly, are the most disruptive. To further investigate the issue, Les Gellis of the Philadelphia Veterans Medical Center and Kenneth Lichstein of the University of Alabama in Tuscaloosa conducted an online survey of 128 "good" and 92 "poor" sleepers - the latter scoring 7 or more on a 21-point scale called the Pittsburgh Sleep Quality Index. You can rate yourself on the index here (pdf format) - my score was 12. Surprisingly, there was little difference between the good and bad sleepers for many of the factors highlighted on websites offering advice on insomnia - including drinking alcohol or caffeine near to bedtime, or watching television in bed. (I do all of those.) © Copyright Reed Business Information Ltd.

Keyword: Sleep
Link ID: 12514 - Posted: 06.24.2010

by Sunita Reed New research published today says that insulin, the hormone used to treat diabetes, might some day be useful for treating or preventing Alzheimer’s disease. Neuroscientist Bill Klein and colleagues at Northwestern University had previously discovered evidence that Alzheimer’s disease might actually be a form of diabetes of the brain. Prior studies by other researchers found that patients with Alzheimer’s disease had lower levels of insulin, and that their brains were insulin-resistant. Klein discovered that, in addition to the plaques and tangles in brains of those with Alzheimer’s, there were toxic proteins called ADDLs (pronounced "ADD-els"). In normal brains, insulin binds to sites on cells called receptors, triggering a series of events that allow memories to form. By studying rat brain cell cultures in the lab, Klein’s team discovered how ADDLs can interfere with the memory-formation process. When they added the ADDLs, they attached to their own receptors on the cell surface and caused the insulin receptors to disappear. “Insulin in the brain is just not working,” explains Klein. Even though it’s there, it doesn’t have a place to park. Its receptors seem to be less responsive to the insulin. That’s the same thing that occurs in type 2 diabetes outside of the brain." In the current study, Klein and his colleagues at the Federal University of Rio de Janeiro, Brazil, tried a strategy to protect the insulin receptors from damage. Before adding ADDLs, they flooded the brain cells with a high concentration of insulin. The insulin treatment blocked the ADDLs from attaching to the ADDL receptors and completely protected the insulin receptors. ©2009 ScienCentral

Keyword: Alzheimers
Link ID: 12513 - Posted: 06.24.2010

By Joshua Hartshorne The setting: a nursery. A baby speaks directly to the camera: “Look at this. I’m a free man. I go anywhere I want now.” He describes his stock-buying activities, but then his phone interrupts. “Relentless! Hang on a second.” He answers his phone. “Hey girl, can I hit you back?” This E*Trade commercial is only the latest proof of what comedians have known for years: few things are as funny as a baby who talks like an adult. This comedic law obscures an important question: Why don’t young children express themselves articulately? And why is the idea of toddler speaking in perfect sentences so hilarious? Many people assume children learn to talk by copying what they hear. In other words, babies listen to the words adults use and the situations in which they use them and imitate accordingly. Behaviorism, the scientific approach that dominated American cognitive science for the first half of the 20th century, made exactly this argument. This “copycat” theory can’t explain why toddlers aren’t as loquacious adults, however. After all, when was the last time you heard literate adults express themselves in one-word sentences (“bottle,” “doggie”) or in short phrases such as, “Mommy open box.” Of course, showing that a copycat theory of language acquisition can’t explain these strange patterns in child speech is easy. Actually explaining one-word sentences is much harder. Over the past half-century, scientists settled on two reasonable possibilities. © 1996-2009 Scientific American Inc.

Keyword: Language; Development of the Brain
Link ID: 12512 - Posted: 06.24.2010

By BENEDICT CAREY They’re considered a release, a psychological tonic, and to many a glimpse of something deeper: the heart’s own sign language, emotional perspiration from the well of common humanity. Tears lubricate love songs and love, weddings and funerals, public rituals and private pain, and perhaps no scientific study can capture their many meanings. “I cry when I’m happy, I cry when I’m sad, I may cry when I’m sharing something that’s of great significance to me,” said Nancy Reiley, 62, who works at a women’s shelter in Tampa, Fla., “and for some reason I sometimes will cry when I’m in a public speaking situation. “It has nothing to do with feeling sad or vulnerable. There’s no reason I can think of why it happens, but it does.” Now, some researchers say that the common psychological wisdom about crying — crying as a healthy catharsis — is incomplete and misleading. Having a “good cry” can and usually does allow people to recover some mental balance after a loss. But not always and not for everyone, argues a review article in the current issue of the journal Current Directions in Psychological Science. Placing such high expectation on a tearful breakdown most likely sets some people up for emotional confusion afterward. Copyright 2009 The New York Times Company

Keyword: Emotions
Link ID: 12511 - Posted: 06.24.2010

By Bruce Bower Dreams don’t just bubble up at night and then evaporate like morning dew once the sun rises. What you dream shapes what you think about your upcoming plans and your closest confidants, especially if nighttime reveries fit with what’s already convenient to believe, a new report finds. In an effort to understand whether people take their dreams seriously, Carey Morewedge of Carnegie Mellon University in Pittsburgh and Michael Norton of Harvard University surveyed 149 college students attending universities in India, South Korea or the United States about theories of dream function. People across cultures often assume that dreams contain hidden truths, much as Sigmund Freud posited more than a century ago, Morewedge and Norton report in the February Journal of Personality and Social Psychology. In fact, many individuals consider dreams to provide more meaningful information regarding daily affairs than comparable waking thoughts do, the two psychologists conclude. Ideas that dreams come from the brain’s random output or are essential for daily problem-solving or for weeding out the routine clutter in one’s mind appeal to a minority of people, the scientists say. In a series of experiments, the researchers also probed interpretations of various real and imagined dreams in a national sample of 270 people surveyed online, 656 commuters and pedestrians interviewed in Boston and Cambridge, Mass., and 60 college students. © Society for Science & the Public 2000 - 2009

Keyword: Sleep
Link ID: 12510 - Posted: 06.24.2010

By Judy Foreman A troubled, gun-wielding 23-year-old student at Virginia Polytechnic Institute goes on a campus rampage, killing 32 people and eventually himself. An MIT student commits suicide by ingesting cyanide, and another dies in a fire after an overdose. Such highly publicized occurrences underscore the sense of personal angst on today's college campuses. But contrary to popular belief, the stress young people experience has nothing to do with meeting the demands of higher education. It comes simply with being a newly minted adult. Whether in college or not, almost half of this country's 19-to-25-year-olds meet standard criteria for at least one psychiatric disorder, although some of the disorders, such as phobias, are relatively mild, according to a government-funded survey of more than 5,000 young adults, published in December in the Archives of General Psychiatry. The study, done at Columbia University and called the National Epidemiologic Study on Alcohol and Related Conditions, found more alcohol use disorders among college students, while their noncollege peers were more likely to have a drug use disorder. But, beyond that, misery is largely an equal-opportunity affliction: Across the social spectrum, young people in America are depressed. They're anxious. They regularly break one another's hearts. And, all too often, they don't get the help they need as they face life's questions: © 2009 NY Times Co.

Keyword: Development of the Brain; Emotions
Link ID: 12509 - Posted: 06.24.2010

by Peter Aldhous GASTRIC surgery is a last resort for people who are dangerously obese. But there may soon be a gentler option in the shape of a removable device inserted into the gut though the mouth. The EndoBarrier, developed by GI Dynamics of Lexington, Massachusetts, is an impermeable sleeve that lines the first 60 centimetres of the small intestine. In animal experiments and preliminary human trials, it reduces weight and rapidly brings type II diabetes under control. Given the rising tide of obesity across the developed world, new treatments are a matter of priority. In the US alone, more than 15 million adults meet the criteria for gastric surgery because they have a body mass index of more than 40, or a BMI of 35 plus a complication such as diabetes. While the operations do cause dramatic and sustained weight loss, their high cost and concerns about the risk of dying on the operating table mean only a fraction of those who might benefit go on to have the surgery. According to the American Society for Metabolic and Bariatric Surgery, around 220,000 people in the US had gastric surgery for weight loss in 2008. GI Dynamics is not the only company working on alternatives (see "Wired for weight loss"), but its approach is appealing for its simplicity and low cost. The device, enclosed in a capsule, is inserted via the mouth using an endoscope. Once in place below the base of the stomach, the capsule releases a small ball that with the help of a catheter pulls a flexible sleeve made of the slippery polymer PTFE through the intestine. The ball is jettisoned and the sleeve fixed in place by releasing a spiked attachment made from the shape-memory metal alloy nitinol. © Copyright Reed Business Information Ltd.

Keyword: Obesity
Link ID: 12508 - Posted: 06.24.2010

By Carolyn Y. Johnson The humble honeybee can count - at least, sort of. New research shows that honeybees can tell the difference between different numbers of objects, up to four. That means the buzzing insects join the ranks of the numerically competent - pigeons, raccoons, dolphins, monkeys, songbirds, salamanders, and monkeys, all of which have been shown to have some form of numerical ability. The researchers are quick to note their results do not suggest that honeybees can actually put numbers in order or do math. But it does show bees can see features in visual patterns. Even if Pythagoras isn't at work in the hive, the work shines a light on an insect whose intellect is outsized for its buzzing body and minuscule brain. "Is it surprising? No. Is it amazing? Absolutely," said Kim Flottum, president of the Eastern Apicultural Society and editor of Bee Culture, who was not involved in the study. "Bees are just incredibly interesting . . . they just keep showing us things they can do that we didn't think anything as small as a bee should be able to do." To test bees' ability to recognize different numbers, researchers in Australia and Germany first trained bees to recognize one pattern of dots. The bees flew into a tunnel whose opening was marked with that pattern, then continued until they came to a fork in the tunnel, with the ability to go right or left. One choice was marked with the same dot pattern as the tunnel opening, the other with a different pattern. The bees that chose the matching pattern received a reward of sugar water. © 2009 NY Times Co.

Keyword: Miscellaneous
Link ID: 12507 - Posted: 06.24.2010

Reading a book triggers an active response in a person's brain, replicating the activity described in the story, a study by Washington University researchers in St. Louis, Mo., indicates. A brain-imaging study at Washington University tracked brain activity as participants read sections of a story. What scientists discovered was that parts of the brain associated with certain activities described in the story would light up as the person read those sections. For instance, if a character pulled a light cord in the story, the frontal lobe region, which controls grasping motions, would increase in activity. "There has been good evidence for a while that mental simulation — imagination — can improve performance in sport and other skilled behaviours. This study suggests that readers do mental simulation when they comprehend a story," Jeffrey Zacks, director of the university's dynamic cognition laboratory, told the Guardian newspaper. Zacks is also co-author of the study, soon to be published in the journal Psychological Science. The study's lead author is Nicole Speer. © CBC 2009

Keyword: Brain imaging; Language
Link ID: 12506 - Posted: 06.24.2010

By Carey Goldberg Marcie Lipsitt found that all she had to do was page Dr. Joseph Biederman or another doctor on his pediatric psychiatry team with that message, and she would get a call back within two minutes to help her through her son Andrew's latest violent crisis. Lynn Tesher credits the Biederman team at Massachusetts General Hospital with giving her several more years with her daughter, Ariel. Tormented from early childhood by rages and emotional pain, Ariel jumped to her death from her Manhattan balcony at age 20, but without the care from Biederman's team, Tesher is convinced, "she would not have lived past 13." For these mothers and some other parents, conflict-of-interest allegations against Biederman, one of the nation's leading child psychiatrists, are not just baffling, but personally upsetting. They see the doctor, a member of the Harvard Medical School faculty, being investigated by a powerful member of Congress and portrayed in the media as an apparent example of how drug company money taints medicine. To some, what is really under attack is child psychiatry, the research that aims to improve how it is practiced, and the terribly ill children who need help. US Senator Charles E. Grassley, Republican of Iowa, has accused Biederman of failing to tell Harvard until last March about most of the more than $1.5 million that the pharmaceutical industry paid him in consulting and speaking fees between 2000 and 2007. Biederman also created a research center with funding from Johnson & Johnson, a company that sells a popular antipsychotic drug. © 2009 NY Times Co.

Keyword: Development of the Brain; Schizophrenia
Link ID: 12505 - Posted: 06.24.2010

By Coco Ballantyne A Charlotte, N.C., man was charged with first-degree murder of a 79-year-old woman whom police said he scared to death. In an attempt to elude cops after a botched bank robbery, the Associated Press reports that 20-year-old Larry Whitfield broke into and hid out in the home of Mary Parnell. Police say he didn't touch Parnell but that she died after suffering a heart attack that was triggered by terror. Can the fugitive be held responsible for the woman's death? Prosecutors said that he can under the state's so-called felony murder rule, which allows someone to be charged with murder if he or she causes another person's death while committing or fleeing from a felony crime such as robbery—even if it's unintentional. But, medically speaking, can someone actually be frightened to death? We asked Martin A. Samuels, chairman of the neurology department at Brigham and Women's Hospital in Boston. Is it possible to literally be scared to death? Absolutely, no question about it. Really? How does that happen? The body has a natural protective mechanism called the fight-or-flight response, which was originally described by Walter Cannon [chairman of Harvard University's physiology department from 1906 to 1942]. If, in the wild, an animal is faced with a life-threatening situation, the autonomic (involuntary) nervous system responds by increasing heart rate, increasing blood flow to the muscles, dilating the pupils, and slowing digestion, among other things. All of this increases the chances of succeeding in a fight or running away from, say, an aggressive jaguar. This process certainly would be of help to primitive humans, but the problem, of course, is that in the modern world there is very limited advantage of the fight-or-flight response. There is a downside to revving up your nervous system like this. © 1996-2009 Scientific American Inc.

Keyword: Emotions; Stress
Link ID: 12504 - Posted: 06.24.2010

By Nathan Seppa Chronically elevated blood levels of the simple sugar glucose may contribute to poor cognitive function in elderly people with diabetes, a study in the February Diabetes Care suggests. But whether these levels add to a person’s risk of developing dementia is unclear, the study authors say. People with diabetes face a risk of old-age dementia that’s roughly 50 percent greater than those without diabetes, past studies have shown. Research has also hinted that surges in blood sugar might account for some of that added risk. Many previous studies have tested for elevated blood glucose by obtaining a snapshot blood sample taken after a person has fasted for a day. In the new study, Tali Cukierman-Yaffe, an endocrinologist at Tel-Aviv University and McMaster University in Hamilton, Canada, teamed with an international group of colleagues to assess blood glucose levels in nearly 3,000 diabetes patients by measuring A1c, shorthand for HbA1c or glycosylated hemoglobin. Since sugar in the blood sticks to the hemoglobin protein in red blood cells, the A1c test reveals an average sugar level over two or three months. In addition to collecting these blood glucose readings, the scientists also asked each volunteer to take a 30-minute battery of four standardized tests designed to assess memory, visual motor speed, capacity for learning and managing multiple tasks. © Society for Science & the Public 2000 - 2009

Keyword: Alzheimers; Obesity
Link ID: 12503 - Posted: 06.24.2010

By Benjamin Lester Inspirational followers may be just as important as stellar leaders, at least in fish. A new study finds that timid three-spined sticklebacks can inspire greater daring in their bold counterparts. The findings illustrate that leadership may be as much a product of social context as of individual temperament. Over the past several years, researchers have worked to understand how complex group behaviors arise from simple decisions by individuals. For instance, an ant trail might form on one tree branch instead of another because the first few ants randomly picked that branch and later ants followed their scent. But according to evolutionary biologist Andrea Manica and his colleagues at the University of Cambridge in the United Kingdom, much of the work has focused on situations in which all individuals are genetically very similar, such as groups of social insects. Less well understood, says Manica, is how the greater, individual differences in vertebrates' personalities can influence group behavior. In these situations, certain individuals often become group leaders. Previous studies have identified boldness--the amount of time an individual is willing to stay exposed in order to forage for food--as a trait of leaders in groups of sticklebacks (Gasterosteus aculeatus). To understand how boldness could translate into leadership, the Cambridge team set up aquaria in which one side was a "safe area" with deep water and plastic plants and the other side was a "risky," exposed area designed to make the fish feel vulnerable to being eaten by birds. The team placed one stickleback in each aquarium half, separated them with an opaque divider, and trained the fish to expect food only in the exposed area: To eat, the fish had to take risks. The scientists then observed each fish's behavior and assigned it a score on a boldness scale. They then randomly repaired the fish, using the boldness scores to classify each fish as either "bold" or "shy," relative to its new partner. This time they inserted clear and opaque dividers into the tanks. © 2009 American Association for the Advancement of Science.

Keyword: Animal Communication; Emotions
Link ID: 12502 - Posted: 06.24.2010

By Jesse Bering I wish I could say that I decided to come out of the closet in my early twenties for more admirable reasons—such as for love or the principle of the thing. But the truth is that passing for a straight person had become more of a hassle than I figured it was worth. Since the third grade, I’d spent too many valuable cognitive resources concocting deceptive schemes to cover up the fact that I was gay. In fact, my earliest conscious tactic to hide my homosexuality involved being outlandishly homophobic. When I was eight years old, I figured that if I used the word “fag” a lot and on every possible occasion expressed my repugnance for gay people, others would obviously think I was straight. But, although it sounded good in theory, I wasn’t very hostile by temperament and I had trouble channeling my fictitious outrage into convincing practice. I may have failed as a homophobe, but unfortunately, many people succeed. And it turns out we may have something in common—many young, homophobic males may secretly harbor homosexual desires (whether they are consciously trying to deceive the world about them as I was or not even aware they exist). One of the most important lines of work in this area dates back to a 1996 article published in The Journal of Abnormal Psychology. In this empirical paper, researchers Henry Adams, Lester Wright, Jr., and Bethany Lohr from the University of Georgia report evidence that homophobic young males may secretly have gay urges. © 1996-2009 Scientific American Inc

Keyword: Sexual Behavior; Aggression
Link ID: 12501 - Posted: 06.24.2010

By Martin Enserink Serotonin, the brain chemical involved in depression, anger, and a variety of other human behaviors, turns out to have another surprising role: It transforms desert locusts from solitary, innocuous bugs into swarming, voracious pests that can ravage orchards and fields in a matter of hours. The findings, published in tomorrow's issue of Science, could point the way to new locust-control methods that don't rely on insecticides. Most of the time, the desert locust (Schistocerca gregaria) is a bland, greenish insect that lives an inconspicuous life, shunning other members of its species and flying only by night. But when their densities reach a certain threshold, locusts become gregarious: They seek out one another's company, start reproducing explosively, and eventually form massive swarms that can move thousands of kilometers beyond their usual habitats and create havoc of biblical proportions. The behavior changes are accompanied by a complete physical makeover, taking several generations, during which the insects first turn pink and eventually black and bright yellow. A team of researchers based at three universities in the United Kingdom and Australia had previously discovered that the change from solitary to gregarious starts when locusts see and smell one another, or when their hind legs touch one another, a stimulus researchers can imitate in the lab by gently tickling them. In a 2004 paper, the group also showed that levels of 13 brain chemicals differ between insects in the two stages (Science, 10 December 2004, p. 1881). Now, the researchers have singled out serotonin as "the first domino to fall, the one that sets the entire process in motion," says lead author Michael Anstey of the University of Oxford in the U.K. © 2009 American Association for the Advancement of Science

Keyword: Aggression
Link ID: 12500 - Posted: 06.24.2010

by Linda Geddes For the first time, some of the disability associated with the early stages of multiple sclerosis appears to have been reversed. The treatment works by resetting patients' immune systems using their own stem cells. While randomised clinical trials are still needed to confirm the findings, they offer new hope to people in the early stages of the disease who don't respond to drug treatment. Multiple sclerosis is an autoimmune disease in which the fatty myelin sheath that wraps around nerve cells and speeds up their rate of transmission comes under attack from the body's own defences. Clean slate Richard Burt of Northwestern University Feinberg School of Medicine in Chicago and his colleagues had previously tried using stem cells to reverse this process in patients with advanced stages of the disease, with little success. "If you wait until there's neuro-degeneration, you're trying to close the barn door after the horse has already escaped," says Burt. What you really want to do is stop the autoimmune attack before it causes nerve-cell damage, he adds. In the latest trial, his team recruited 12 women and 11 men in the early relapsing-remitting stage of MS, who had not responded to treatment with the drug, interferon beta, after six months. © Copyright Reed Business Information Ltd.

Keyword: Multiple Sclerosis; Stem Cells
Link ID: 12499 - Posted: 06.24.2010

By Bruce Bower Good parenting provides a potent buffer against some youngsters’ genetic predisposition to use alcohol, cigarettes and marijuana by age 14, a new study finds. Uninvolved, unsupportive parenting heralds a spike in consumption of these substances among genetically vulnerable teens, reports a team led by psychologist Gene Brody of the University of Georgia in Athens. Brody and his colleagues conducted what to their knowledge is the first long-term examination of how parenting practices combine with a child’s genetic makeup to either prompt or prevent early drug use. Their results, based on a three-year study of rural, black youths from working poor families, a population that Brody’s Center for Family Research works with regularly, appear in the February Journal of Consulting and Clinical Psychology. “Our study emphasizes that there are protective processes in children’s lives, such as effective parenting, that shield them from a genetic risk for early substance use,” Brody says. His team focused on variations in the serotonin transporter gene, or 5HTT. This gene assists in regulating transmission of serotonin, a chemical messenger in the brain. Many people carry two copies of a long version of 5HTT. But approximately 40 percent of people inherit either one or two copies of a short version of the gene. Having at least one short version lessens serotonin transmission, relative to two long versions. © Society for Science & the Public 2000 - 2009

Keyword: Drug Abuse; Sexual Behavior
Link ID: 12498 - Posted: 06.24.2010

Brain cells called astrocytes help to cause the urge to sleep that comes with prolonged wakefulness, according to a study in mice, funded by the National Institutes of Health. The cells release adenosine, a chemical known to have sleep-inducing effects that are inhibited by caffeine. "Millions of Americans suffer from disorders that prevent a full night's sleep, and others—from pilots to combat soldiers – have jobs where sleepiness is a hazard. This research could lead to better drugs for inducing sleep when it is needed, and for staving off sleep when it is dangerous," says Merrill Mitler, Ph.D., a program director with the NIH's National Institute of Neurological Disorders and Stroke (NINDS). The study appears Jan. 29, 2009 in Neuron, and was funded by NINDS, the National Institute of Mental Health (NIMH) and the National Institute on Aging (NIA), all part of NIH. It is the result of a collaboration among Michael Halassa, M.D., and Philip Haydon, Ph.D., at Tufts University School of Medicine in Boston and Marcos Frank, Ph.D., and Ted Abel, Ph.D. at the University of Pennsylvania School of Medicine in Philadelphia. Although the exact purpose of sleep is unknown, everyone seems to need it, and some research suggests that it strengthens memories by adjusting the connections between neurons. As the waking hours tick by, all animals experience an increasing urge to sleep, known as sleep pressure. If sleep is delayed, a deep, long sleep usually follows as the body's means of compensating. Prior studies pointed to adenosine as a trigger for sleep pressure. The chemical accumulates in the brain during waking hours, eventually helping to stimulate the unique patterns of brain activity that occur during sleep.

Keyword: Sleep; Glia
Link ID: 12497 - Posted: 06.24.2010