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

LONDON - Doctors have long assumed that most antidepressants are interchangeable. But according to a new study, Zoloft and Cipralex work slightly better than 10 other popular drugs, and should be psychiatrists’ first choice for patients with moderate to severe depression. Previous research found few differences between antidepressants. A U.S. government study in 2006 concluded that patients with major depression did equally well on different drugs. But in a paper published online Thursday in the Lancet medical journal, two antidepressants came out on top, though only marginally. International doctors examined more than 100 previous studies on a dozen antidepressants, which included nearly 26,000 patients from 1991 to 2007. They found that Zoloft, developed by Pfizer Inc., and Cipralex, developed by Forest Laboratories in the U.S. and Danish drugmaker H. Lundbeck A/S in Europe, were the best options when considering benefits, side effects and cost. In contrast, Pfizer’s Edronax was the least effective. The other drugs tested were Celexa, Cymbalta, Efexor, Ixel, Luvox, Prozac, Seroxat, Remeron, and Zyban. “The bottom line is that there is a rational hierarchy when prescribing antidepressants,” said Dr. Andrea Cipriani, the study’s lead author, of the University of Verona in Italy. © 2009 The Associated Press.

Keyword: Schizophrenia
Link ID: 12496 - Posted: 06.24.2010

By Christof Koch At the heart of science are judicious observations and measurements. This reality presupposes that something can be measured. But how can consciousness—the notorious ineffable and ethereal stuff that can’t even be rigorously defined—be measured? Recent progress makes me optimistic. Consider a problem of great clinical, ethical and legal relevance, that of in­ferring the presence of consciousness in severely brain-damaged patients. ­Often the victims of traffic accidents, cardiac arrests or drug overdoses, such patients have ­periods when they are awake, and they may spontaneously open their eyes. On occasion, their head turns in response to a loud noise, or their eyes might briefly track an object, but never for long. They might grind their teeth, swallow or smile, but such activities occur sporadically, not on command. These fragmentary acts appear reflexlike, generated by an intact brain stem. As many as 25,000 such “vegetative” patients in hospices and nursing homes hover for years in this limbo, at a steep emotional and financial cost. The extent of the damage and the persistent absence of purposeful behavior usually leave little doubt that consciousness has fled the body for good. Terri Schiavo was such a case, alive but unconscious for 15 years before her court-ordered death in 2005 in Florida. Even worse, though, is the possibility that some of these patients may experience some remnants of consciousness, unable to communicate their feelings of discomfort or pain, agonizing thoughts or poignant memories to the outside world. Until recently, nothing could be done to diagnose when an awake mind was entombed inside a damaged brain. © 1996-2009 Scientific American Inc.

Keyword: Miscellaneous
Link ID: 12495 - Posted: 06.24.2010

By Johannes Haushofer and Ernst Fehr Imagine you are serving on a jury: the defendant is charged with murder, but he also suffers from a brain tumor that causes erratic behavior. Is he to be held responsible for the crime? Now imagine you are the judge: What should the defendant’s sentence be? Does the tumor count as a mitigating circumstance? The assignment of responsibility and the choice of an appropriate punishment lie at the heart of our justice system. At the same time, these are cognitive processes like many others—reasoning, remembering, decision-making—and as such must originate in the brain. These two facts lead to the intriguing question: How does the brain enable judges, juries, and you and me to perform these tasks? What are the neural mechanisms that let you decide whether someone is guilty or innocent? A recent study published in the December 2008 issue of the journal Neuron, by Joshua Buckholtz and his colleagues at Vanderbilt University tackles exactly this question. Until recently, such topics would have been out of the reach of cognitive neuroscience for lack of methods; today, functional magnetic resonance imaging (fMRI) allows researchers to watch the brain “in action” as normal human participants make decisions about responsibility and punishment. In the new study, Buckholtz and colleagues asked participants to read vignettes describing hypothetical crimes that a fictitious agent, “John,” commits against another person. The stories were divided into three conditions: in the first, the “responsibility” (R) condition, the perpetrator was fully responsible for the negative consequences of his action against the victim; for instance, John might have intentionally pushed his fiancée’s lover off a cliff. In the “diminished responsibility” (DR) condition, mitigating circumstances were present that reduced John’s responsibility; imagine that John committed the same crime, but suffered from a brain tumor. © 1996-2009 Scientific American Inc.

Keyword: Emotions
Link ID: 12494 - Posted: 06.24.2010

By Rachel Zelkowitz Did Grandma seem forgetful at the holiday parties last month? It could be time to put her on a diet. Sharply reducing calories improves memory in older adults, according to one of the first studies of dietary restriction and cognitive function in humans. Research on the benefits of an extremely low-calorie diet stretches back to the 1930s, when scientists found that rats lived up to twice as long when they nibbled less than control animals. Since then, some studies with rodents and nonhuman primates have shown that this spare diet, known as calorie restriction, improves some markers of diabetes and heart disease, such as blood glucose and triglyceride levels, and possibly prevents neurological declines similar to those seen with Alzheimer's disease and Parkinson's disease. In humans, however, the results have been mixed. Subjects on low-calorie diets generally have lower blood pressure and blood sugar levels than their chow-happy counterparts. But these studies were small, and none was designed to test how calorie restriction might affect cognitive performance. To fill that void, neurologist Agnes Flöel and her colleagues at the University of Muenster in Germany recruited 50 healthy elderly subjects. The average volunteer was 60 years old and overweight, with a body mass index of 28. The researchers randomly assigned the volunteers to one of three groups. Twenty people were instructed to reduce their daily calorie intake by 30%, while still eating a balanced diet of nutrient-rich carbohydrates, fats, and lean proteins. Another 20 were told to keep their caloric intake the same but increase their consumption of unsaturated fatty acids, such as those found in salmon or olive oil. (Previous studies have linked a diet rich in these fats to improved cognition.) The remaining 10 volunteers did not change their diets. © 2009 American Association for the Advancement of Science.

Keyword: Alzheimers; Learning & Memory
Link ID: 12493 - Posted: 06.24.2010

By Laura Sanders In 1985, Monday Night Football fans looked on as Washington Redskins quarterback Joe Theismann was sacked. The collision was so forceful that it snapped Theismann’s leg, breaking like, as one fan put it, a “stale chopstick.” Most audience members likely empathized with Theismann’s pain, including people afflicted with a rare disorder that prevents them from feeling pain themselves, a new study suggests. Instead of using past experiences of feeling pain to commiserate, such people likely rely on the ability to imagine the pain of others, suggests the brain-imaging study, published online January 28 in Neuron. “This fascinating and well-conducted study” gives new insights into the relationship between pain and empathy, comments Marco Loggia of the Athinoula A. Martinos Center for Biomedical Imaging in Charlestown, Mass. The study suggests that multiple brain regions, including regions involved in emotions, can be recruited to feel empathy for others’ pain. In future studies, Loggia says, it would be interesting to examine other cases when people are exposed to someone else’s feelings without ever having felt such feelings firsthand. “How can humans empathize with a dog that hurt its tail? How can a man understand menstrual pain?” Loggia asks. The answers, he proposes, may lie in the same regions of the brain that allow pain-insensitive people to empathize with others’ pain. © Society for Science & the Public 2000 - 2009

Keyword: Pain & Touch; Emotions
Link ID: 12492 - Posted: 06.24.2010

(CNN) -- For years after his NFL career ended, Ted Johnson could barely muster the energy to leave his house. "I'd [leave to] go see my kids for maybe 15 minutes," said Johnson. "Then I would go back home and close the curtains, turn the lights off and I'd stay in bed. That was my routine for two years. "Those were bad days." These days, the former linebacker is less likely to recount the hundreds of tackles, scores of quarterback sacks or the three Super Bowl rings he earned as a linebacker for the New England Patriots. He is more likely to talk about suffering more than 100 concussions. "I can definitely point to 2002 when I got back-to-back concussions. That's where the problems started," said Johnson, who retired after those two concussions. "The depression, the sleep disorders and the mental fatigue." Until recently, the best medical definition for concussion was a jarring blow to the head that temporarily stunned the senses, occasionally leading to unconsciousness. It has been considered an invisible injury, impossible to test -- no MRI, no CT scan can detect it. © 2009 Cable News Network.

Keyword: Brain Injury/Concussion
Link ID: 12491 - Posted: 06.24.2010

Reducing what you eat by nearly a third may improve memory, according to German researchers. They introduced the diet to 50 elderly volunteers, then gave them a memory test three months later. The study, reported in the Proceedings of the National Academy of Sciences journal, found significant improvements. However, a dietician said the reduction could harm health unless care was taken. There is growing interest in the potential benefits of calorie restricted diets, after research in animals suggested they might be able to improve lifespan and delay the onset of age-related disease. However, it is still not certain whether this would be the case in humans - and the the levels of "caloric restriction" involved are severe. The precise mechanism which may deliver these benefits is still being investigated, with theories ranging from a reduction in the production of "free radical" chemicals which can cause damage, to a fall in inflammation which can have the same result. The researchers from the University of Munster carried out the human study after results in rats suggested that memory could be boosted by a diet containing 30% fewer calories than normal. The study volunteers, who had an average age of 60, were split into three groups - the first had a balanced diet containing the normal number of calories, the second had a similar diet but with a higher proportion of unsaturated fatty acids, such as those found in olive oil and fish. The final group were given the calorie restricted diet. After three months, there was no difference in memory scores in the first two groups, but the 50 in the third group performed better. They also showed other signs of physical improvement, with decreased levels of insulin and fewer signs of inflammation. The researchers said that these changes could explain the better memory scores, by keeping brain cells in better health. (C)BBC

Keyword: Learning & Memory; Obesity
Link ID: 12490 - Posted: 01.27.2009

Reaching for a cigarette to cope with a flashback is all too common among sufferers of post-traumatic stress disorder (PTSD), but scientists say that although the nicotine hit may feel good, its brain action probably makes PTSD worse in the long run. Here's the rub: At least half of PTSD sufferers smoke, and others wind up dependent on alcohol, anti-anxiety pills, sometimes even illegal drugs. Yet, too few clinics treat both PTSD and addictions at the same time, despite evidence they should. Now studies are recruiting PTSD patients — from New England drug-treatment centres to veterans clinics in North Carolina and Washington — to determine what type of combination care works best. "It's kind of a clinical myth that you can only do one at a time or should only do one at a time," says Duke University PTSD specialist Dr. Jean Beckham, a psychologist at the Durham, N.C., Veterans Affairs (VA) Medical Center. "Everybody's afraid to have their patients quit smoking because they're afraid they're going to get worse. There's not a lot of empirical data about that." Beckham's research on how to break the nicotine-and-PTSD cycle raises a provocative question for a tobacco-prone military: Are people at higher risk of developing PTSD if they smoke before they experience the violent event or episode? © CBC 2009

Keyword: Drug Abuse; Stress
Link ID: 12489 - Posted: 06.24.2010

By SUSAN OKIE BALTIMORE — One sister is 14; the other is 9. They are a vibrant pair: the older girl is high-spirited but responsible, a solid student and a devoted helper at home; her sister loves to read and watch cooking shows, and she recently scored well above average on citywide standardized tests. There would be nothing remarkable about these two happy, normal girls if it were not for their mother’s history. Yvette H., now 38, admits that she used cocaine (along with heroin and alcohol) while she was pregnant with each girl. “A drug addict,” she now says ruefully, “isn’t really concerned about the baby she’s carrying.” When the use of crack cocaine became a nationwide epidemic in the 1980s and ’90s, there were widespread fears that prenatal exposure to the drug would produce a generation of severely damaged children. Newspapers carried headlines like “Cocaine: A Vicious Assault on a Child,” “Crack’s Toll Among Babies: A Joyless View” and “Studies: Future Bleak for Crack Babies.” But now researchers are systematically following children who were exposed to cocaine before birth, and their findings suggest that the encouraging stories of Ms. H.’s daughters are anything but unusual. So far, these scientists say, the long-term effects of such exposure on children’s brain development and behavior appear relatively small. Copyright 2009 The New York Times Company

Keyword: Drug Abuse; Development of the Brain
Link ID: 12488 - Posted: 06.24.2010

Jennifer Viegas -- Music appreciation begins in the womb, suggests new research that found newborns can feel the beat, even in their sleep. The findings indicate beat perception, and possibly other aspects of music appreciation, are innate, which in turn may mean musicality could carry some evolutionary advantage for all humans. "Our results suggest that beat detection does not require voluntary attention," said lead author Istvan Winkler. "We did not test infants when they were awake," added Winkler, a researcher at the Institute for Psychology at the Hungarian Academy of Sciences. "This is because newborns are usually restless when they are awake, often hungry and crying." Winkler and his team presented 14 healthy newborn infants, between 37 and 40 weeks old, with an R&B-style music snippet composed of snare, bass and hi-hat. Every so often they would break the rhythm by removing a downbeat. The infants were outfitted with non-invasive scalp electrodes that measured their brain activity while the music played. According to a paper published in this week's Proceedings of the National Academy of Sciences, the researchers found that omitting the downbeat elicited brain activity in the newborns associated with a violation of sensory expectations. Instead of hearing something like, "boom chicka boom chicka boom..." the infants heard something akin to, "boom chicka boom chicka chicka...," which the auditory and frontal cortex parts of their brains registered. © 2009 Discovery Communications, LLC

Keyword: Hearing; Development of the Brain
Link ID: 12487 - Posted: 06.24.2010

By Janet Raloff To stay healthy, the body needs its zzz’s. But independent of slumber, human health also appears to require plenty of darkness — especially at night. Or so suggests a pair of new cancer studies. One found that among postmenopausal women, the lower the overnight production of melatonin — a brain hormone secreted at night, especially during darkness — the higher the incidence of breast cancer. The second study correlated elevated prostate cancer incidence around the world with places that have the brightest signatures of light in satellite imagery. Trends seen in both studies bolster animal data indicating that natural nighttime peaks in blood concentrations of melatonin, which tend to occur during sleep, depress the growth of the hormonally sensitive cancers. Light will depress the body’s natural secretion of that hormone, whether someone is awake or asleep. In 2001, Eva S. Schernhammer of Brigham and Women's Hospital in Boston and her colleagues found an elevated risk of breast cancer among women who worked night shifts. The data, gleaned from participants in the long-running Nurses’ Health Study, fit with the idea that the light encountered while working nocturnal hours would have suppressed the women’s melatonin production. © Society for Science & the Public 2000 - 2009

Keyword: Biological Rhythms; Hormones & Behavior
Link ID: 12486 - Posted: 06.24.2010

By Brian Alexander Weight gain is not always just a matter of lacking willpower, but has more to do with how your brain reacts to what it sees, according to a new study by neuroscientists. For some people, just looking at tasty images of food is enough to make them want to eat. Individuals who are more susceptible to cravings after smelling or seeing food — even if they aren’t hungry — have what researchers call “external food sensitivity,” or EFS. In the new study, conducted by scientists at the British Medical Research Council, brain scans revealed how this food sensitivity influences people's eating habits. A recent U.S. government study found that the number of obese American adults now outweighs the number of those who are merely overweight. While many factors contribute to excessive weight gain — from diet and cultural changes to decreased physical activity — there's still a prevalent attitude that obesity is the fat person's fault. The researchers Andrew Calder, Luca Passamonti and James Rowe were trying to determine why some people are more likely to overeat. What they found was, “people who appear to be more sensitive to food signals have different wiring in their brains,” said obesity expert Marc-Andre Cornier, M.D., a University of Colorado endocrinologist who was not associated with the trial. © 2009 msnbc.com.

Keyword: Obesity; Genes & Behavior
Link ID: 12485 - Posted: 06.24.2010

Just one brain cell is capable of holding fleeting memories vital for our everyday life, according to US scientists. A study of mouse brain cells revealed how they could keep information stored for as long as a minute. A UK specialist said that understanding these short-term memories might help unlock the secrets of Alzheimer's Disease. The finding was reported in the journal Nature Neuroscience. The difference between the brain's long-term and short-term memory has been likened to the RAM of a computer and the hard-drive. To perform normal functions, we need the ability to store, quickly and reliably, large amounts of data, but only a small amount of this needs to be retained in the longer term. Scientists have spent decades working out which parts of the brain are responsible for these functions, and how cells manage this feat. Original theories suggested the memories were retained by multiple cells forming "circuits" around which electrical impulses were fired for the necessary period. More recent ideas have centred around the concept that even an individual cell could somehow hold on to information. Researchers from the University of Texas Southwestern looked at brain cells taken from mice using tiny electrodes to measure their function. They found that a particular component of the cells in question, a chemical receptor, which, when switched on, tells the cell to start an internal signal system that holds the "memory" in place. The next step, they say, is to find out more about this internal system so that it could be targeted by drugs with the aim of improving memory. Dr Don Cooper, the lead researcher, said: "If we can identify and manipulate the molecular components of memory, we can develop drugs that boost the ability to maintain this memory trace to hopefully allow a person to complete tasks without being distracted." (C)BBC

Keyword: Learning & Memory
Link ID: 12484 - Posted: 01.26.2009