By Melinda Wenner Americans take more antidepressants than they do any other type of prescription drug, and pregnant women are no exception. One out of every eight pregnant women in the U.S. takes selective serotonin re­up­take inhibitors (SSRIs) to treat depression or other mood disorders. A handful of recent studies suggest that these drugs could have adverse effects on infant health: they may increase the risk for rare heart defects, premature delivery, low birth weight and withdrawal symptoms. Nevertheless, some doctors argue that the benefits these drugs provide still outweigh the potential risks. Worries over the use of SSRIs during pregnancy first surfaced in journal articles published in the 1980s, but it was not until 2005 that the U.S. Food and Drug Administration conceded that babies born of mothers who take paroxetine (sold as Paxil and Seroxa) during their first trimester are up to twice as likely to exhibit fetal heart defects. A 2005 study published in the Lancet also found that some newborns born of mothers taking paroxetine suffer from withdrawal symptoms such as convulsions and abnormal crying for several days. More recently, pregnancy risks associated with other SSRIs have also come to light. A study published in the September 26 issue of the British Medical Journal monitored nearly 500,000 Danish children from nationwide registries and found that women who take sertraline (Zoloft), citalopram (Celexa) and fluoxetine (Prozac) are more likely to give birth to babies with heart defects, although the overall risk is still quite low. A study in press in the Journal of Clinical Psychopharmacology notes that women treated with SSRIs during late pregnancy are more likely to give birth to small and premature babies. © 2010 Scientific American,

Keyword: Depression
Link ID: 13766 - Posted: 06.24.2010

More than 55% of multiple sclerosis patients have been found to have constricted blood vessels in their brains, a US study says. The preliminary results are from the first 500 patients enrolled in a trial at the University of Buffalo. The abnormality was found in 56.4% of MS patients and also in 22.4% of healthy controls. The MS Society said it was intriguing but not proof that this caused MS - as one leading expert claims. The New York researchers were testing a theory from Italian researcher, Dr Paolo Zamboni who claims that 90% of MS is caused by narrowed veins. He says the restricted vessels prevent the blood from draining fast enough and injure the brain by causing a build up of iron which leads to MS. He has already widened the blockages in a handful of patients including his wife. MS is a long-term inflammatory condition of the central nervous system which affects the transfer of messages from the nervous system to the rest of the body. The Buffalo team used Doppler ultrasound to scan the patients in different body postures to view the direction of venous blood flow. The 500 MS patients, both adults and children, also underwent MRI scans of the brain to measure iron deposits in surrounding areas of the brain. The full results will be presented at an American neurology conference in April. There were 161 healthy controls. Robert Zivadinov who led the study at the University of Buffalo, said he was "cautiously optimistic and excited" about the preliminary data. "They show that narrowing of the extracranial veins, at the very least, is an important association in multiple sclerosis. We will know more when the MRI and other data collected in this study are available." (C)BBC

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 13765 - Posted: 02.11.2010

Characterized by sudden jerking movements and uncontrollable tics and vocalizations, Tourette’s syndrome is a strange, often misunderstood condition. What is it like to live without full control of your body? Seven men and women talk about living with the twitches of Tourette’s. What is it like to live with a chronic disease, mental illness or confusing condition? In Patient Voices, we feature first person accounts of the challenges patients face as they cope with various health issues. Interactive Feature Patient Voices: Migraine Almost 30 million Americans suffer from migraines. What is it like to live with migraine pain? Six men and women speak about their experiences. Copyright 2010 The New York Times Company

Keyword: Tourettes
Link ID: 13764 - Posted: 06.24.2010

Last week, the British medical journal the Lancet, which had originally published a controversial 1998 study by British researcher Andrew Wakefield that implied a link between autism and the vaccine for measles, mumps and rubella, formally retracted that study. In the wake of this, one of the tantalizing areas to be explored is the role diet might play in the lives of children with autism. Research published in October showed that 1 in 91 children has a disorder somewhere along the autism spectrum, with degrees of severity ranging from mild to major. (Federal figures released in December put that number at 1 in 110.) For now, the only treatment known to help kids with autism -- the most common of the conditions that make up what is known as autism spectrum disorder (ASD) -- is placement in an education program that's appropriate to their specific needs, providing speech and language therapy to boost their ability to communicate, and helping them develop social skills, according to Susan Levy, director of the Regional Autism Center at the Children's Hospital of Philadelphia and a member of the American Academy of Pediatrics' autism subcommittee. But legions of worried and desperate parents and even some physicians have put stock in other remedies, many of them food-related. Some have believed there's a connection between autism and gastrointestinal problems, which was first suggested in the discredited 1998 paper. "The presumed mechanism of action was that people with autism have a leaky gut, which led to abnormal absorption of some of the breakdown products of gluten and casein," Levy explains. That abnormality, in the leaky-gut theory, would allow those byproducts to be absorbed into the bloodstream and somehow cross into the brain. © 2010 The Washington Post Company

Keyword: Autism
Link ID: 13763 - Posted: 06.24.2010

By Katie Moisse Imagine you've lost your job. You have some money saved, and a chance to double it with a gamble. But if you lose the bet, you'll forfeit everything. What would you do? Most people would not gamble their savings, according to Benedetto De Martino of California Institute of Technology, author of a study published February 8 in Proceedings of the National Academy of Science. People tend to choose avoiding losses over acquiring gains—a behavior known as loss-aversion. But people with damage to the amygdala—an almond-shaped part of the brain involved in emotion and decision-making—are more likely to take bigger risks with smaller potential gains, De Martino's study found. Two women with bilateral amygdala damage showed a dramatic reduction in loss aversion compared with age-matched control subjects on a series of experimental gambles, despite understanding full well the values and risks involved. De Martino already suspected that the amygdala was crucial for loss-aversion based on earlier studies using functional magnetic resonance imaging (fMRI). But these two rare cases with damage to the very structure in question allowed De Martino to directly test his hypothesis. "In functional MRI, you never know if the response is reflecting something else. With the amygdala injury, you have an on "off" response," De Martino says. © 2010 Scientific American

Keyword: Emotions; Drug Abuse
Link ID: 13762 - Posted: 06.24.2010

Greg Miller People of many religious faiths share the belief that there is a reality that transcends their personal experience. Now, a study with brain cancer patients hints at brain regions that may regulate this aspect of spiritual thinking. The researchers found that some patients who had surgery to remove part of the parietal cortex became more prone to "self transcendence." Scientists have grown increasingly interested in the origins and neural underpinnings of religious faith. Yet, contrary to some overenthusiastic media reports, brain scans of people of various faiths asked to ponder their relationship with God have so far failed to turn up a "God spot," suggesting instead that many regions of the brain are involved. In the new study, psychologist Cosimo Urgesi of the University of Udine in Italy and colleagues took a different approach, asking 88 brain cancer patients to fill out a widely used personality questionnaire before and after surgery to remove their tumors. One section of the test measures "self transcendence." It asks respondents, for example, about their tendency to become so absorbed in an activity that they lose track of time and place and whether they feel a strong spiritual connection with other people or with nature. Patients with malignant tumors in posterior brain regions, including the temporal and parietal cortex, scored higher on the self-transcendence scale on average than did those with tumors in the frontal cortex, Urgesi and colleagues report today in Neuron. © 2010 American Association for the Advancement of Science.

Keyword: Emotions
Link ID: 13761 - Posted: 06.24.2010

Stuttering may be the result of a glitch in the day-to-day process by which cellular components in key regions of the brain are broken down and recycled, says a study in the Feb. 10 Online First issue of the New England Journal of Medicine. The study, led by researchers at the National Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes of Health, has identified three genes as a source of stuttering in volunteers in Pakistan, the United States, and England. Mutations in two of the genes have already been implicated in other rare metabolic disorders also involved in cell recycling, while mutations in a third, closely related, gene have now been shown to be associated for the first time with a disorder in humans. “For hundreds of years, the cause of stuttering has remained a mystery for researchers and health care professionals alike, not to mention people who stutter and their families,” said James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. “This is the first study to pinpoint specific gene mutations as the potential cause of stuttering, a disorder that affects 3 million Americans, and by doing so, might lead to a dramatic expansion in our options for treatment.” Stuttering is a speech disorder in which a person repeats or prolongs sounds, syllables, or words, disrupting the normal flow of speech. It can severely hinder communication and a person’s quality of life. Most children who stutter will outgrow stuttering, although many do not; roughly 1 percent of adults stutter worldwide. Current therapies for adults who stutter have focused on such strategies as reducing anxiety, regulating breathing and rate of speech, and using electronic devices to help improve fluency.

Keyword: Language; Genes & Behavior
Link ID: 13760 - Posted: 06.24.2010

by Linda Geddes WE'D booked the venue, chosen the bridesmaids' dresses and even decided on the colours of the table decorations. But finding a refrigerated centrifuge and a ready supply of dry ice in rural south-west England was proving tricky. Then there were the worries about getting blood on my silk wedding dress, and what to do if someone fainted. Organising a wedding can be stressful enough, but we had a whole extra dimension to consider. We were turning it into a science experiment to probe what happens in our bodies when we say the words "I do". Our focus was the hormone oxytocin, sometimes dubbed the "cuddle chemical" for its role in promoting bonding, trust and generosity. The usual setting for investigating its effects is a lab where volunteers may be asked to play games that involve trust and generosity, for example. But how well do these contrived tests reflect what happens in real life? I had written several articles about this hormone before, so my wedding last July seemed the perfect chance to see if it would surge in the ultimate public display of affection. I contacted leading oxytocin researcher Paul Zak, head of the Center for Neuroeconomics Studies in Claremont, California, and he leapt at the opportunity to translate his lab studies into real life. The plan was to measure blood levels of oxytocin in the bride, groom, three close members of our families and eight friends both before and after the ceremony. OK, it was a small sample size, but Zak (pictured above) saw this as a pilot study that might point the way for future research, and perhaps even shed some light on why people stage public weddings in the first place. © Copyright Reed Business Information Ltd

Keyword: Hormones & Behavior; Emotions
Link ID: 13759 - Posted: 06.24.2010

By RONI CARYN RABIN Older mothers are more likely than younger ones to have a child with autism, and older fathers significantly contribute to the risk of the disorder when their partners are under 30, researchers are reporting. In a study published online on Monday in the journal Autism Research, the researchers analyzed almost five million births in California during the 1990s, and 12,159 cases of autism diagnosed in those children — a sample large enough to examine how the risk of autism was affected when one parent was a specific age and the other was the same age or considerably older or younger. Previous research found that the risk of autism grew with the age of the father. The new study suggested that when the father was over 40 and the mother under 30, the increased risk was especially pronounced — 59 percent greater than for younger men. By contrast, for women 30 and older, the risk of autism rose 13 percent when the father was over 40. Every five-year increase in a mother’s age raised her risk of having a child with autism by 18 percent; a 40-year-old woman’s risk was 50 percent greater than that of a woman who became a mother in her late 20s, and 77 percent higher than that of a woman under 25. But while the number of California women giving birth in their 40s rose sharply in the 1990s, the researchers said that could not account for the sevenfold rise in autism during the decade. Copyright 2010 The New York Times Company

Keyword: Autism
Link ID: 13758 - Posted: 06.24.2010

by Lindsey Tanner, Associated Press A woman's chance of having a child with autism increase substantially as she ages, but the risk may be less for older dads than previously suggested, a new study analyzing more than 5 million births found. "Although fathers' age can contribute risk, the risk is overwhelmed by maternal age," said University of California at Davis researcher Janie Shelton, the study's lead author. Mothers older than 40 were about 50 percent more likely to have a child with autism than those in their 20s; the risk for fathers older than 40 was 36 percent higher than for men in their 20s. Even at that, the study suggests the risk of a woman over 40 having an autistic child was still less than 4 in 1,000, one expert noted. The new research suggests the father's age appears to make the most difference with young mothers. Among children whose mothers were younger than 25, autism was twice as common when fathers were older than 40 than when dads were in their 20s. autism The findings contrast with recent research that suggested the father's age played a bigger role than the mother's. Researchers and other autism experts said the new study is more convincing, partly because it's larger. Older mothers are known to face increased risks for having children with genetic disorders, and genes are thought to play a role in autism. The study was released Monday in the February issue of the journal Autism Research. © 2010 Discovery Communications, LLC.

Keyword: Autism
Link ID: 13757 - Posted: 06.24.2010

By Steve Connor The brains of people who risk everything when gambling may be wired up differently to those of the naturally cautious, according to a study that appears to have discovered a neurological basis for reckless behaviour. The research found that people were far more gullible to high-risk gambling when a small but distinct part of their brain had been damaged as a result of a rare genetic disorder. They showed little of the natural aversion to losing something of value that most people are born with. Tests on two otherwise healthy women who had suffered damage to a part of the brain called the amygdala, which has already been implicated in the arousal of fear and anxiety, revealed that they were far more ready to lose money through risky gambling behaviour compared to healthy individuals with no such brain damage. The amygdala is an almond-shaped structure deep inside the core of the brain and it is sometimes referred to as the "seat of fear" because of its important role in controlling this basic, primal emotion. It is an ancient part of the brain, existing long before the evolutionary development of the outer "higher cortex" which controls more sophisticated emotional states. "A fully functioning amygdala appears to make us more cautious. We already know that the amygdala is involved in processing fear, and it also appears to make us afraid of losing money," said Professor Ralph Adolphs of University College London. ©independent.co.uk

Keyword: Emotions; Drug Abuse
Link ID: 13756 - Posted: 06.24.2010

By Alice Park To curb the childhood-obesity epidemic, health experts have long urged parents to make healthy changes to their family's lifestyle — such as eating nutritiously, reducing TV time, exercising and getting a good night's sleep. Individually, these behaviors have been linked to a lower risk of obesity in kids, but researchers at Ohio State University were interested in learning whether their effect might be cumulative — that is, whether families who adopted not just one but two or more of these behaviors could reduce their children's risk of obesity even further. (See how to prevent illness at any age.) Led by epidemiologist Sarah Anderson, researchers analyzed data on 8,550 4-year-olds in a national study and found that, indeed, children who practiced two healthy lifestyle behaviors were slimmer than those who adopted only one behavior, while youngsters who implemented three beneficial habits were the least likely to be overweight. "The more of these routines the children had, the lower was their risk of obesity," Anderson says. "If children had all three routines, their risk of obesity was 40% lower than children who had none of the routines." The three behaviors Anderson studied were eating dinner regularly with the family, limiting the amount of time spent in front of the TV, and getting enough sleep. The children who were least likely to be obese ate dinner with their families six or seven times a week, slept for at least 10.5 hours each night and watched less than two hours of television per day. © 2010 Time Inc.

Keyword: Obesity; Development of the Brain
Link ID: 13755 - Posted: 06.24.2010

By Melody Dye At every stage of early development, human babies lag behind infants from other species. A kitten can amble across a room within moments of birth and catch its first mouse within weeks, while its wide-eyed human counterpart takes months to make her first step, and years to learn even simple tasks, such as how to tie a shoelace or skip a rope, let alone prepare a three-course meal. Yet, in the cognitive race, human babies turn out to be much like the tortoise in Aesop’s fable: emerging triumphant after a slow and steady climb to the finish. As adults, we drive fancy sports cars, leap nimbly across football fields and ballet stages, write lengthy dissertations on every conceivable subject, and launch rockets into space. We have a mastery over our selves and our environments that is peculiar to our species. Yet, this victory seems puzzling. In the fable, the tortoise wins the race because the hare takes a nap. But, if anything, human infants nap even more than kittens! And unlike the noble tortoise, babies are helpless, and more to the point, hopeless. They could not learn the basic skills necessary to their independent survival even if they tried. How do human babies manage to turn things around in the end? In a recent article in Current Directions in Psychological Science, Sharon Thompson-Schill, Michael Ramscar and Evangelia Chrysikou make the case that this very helplessness is what allows human babies to advance far beyond other animals. They propose that our delayed cortical development is precisely what enables us to acquire the cultural building blocks, such as language, that make up the foundations of human achievement. Indeed, the trio makes clear that our early vulnerability is an evolutionary “engineering trade-off,” much like the human larynx—which, while it facilitates the intricate productions of human speech, is actually quite a precarious adaptation for anyone trying to swallow safely. In the same way, they suggest, our ability to learn language comes at the price of an extended period of cognitive immaturity. © 2010 Scientific American,

Keyword: Development of the Brain; Evolution
Link ID: 13754 - Posted: 06.24.2010

By CLAUDIA DREIFUS At his Princeton laboratory, Samuel Wang is searching for basic information on how the brains of humans and dogs work. Dr. Wang, 42, an associate professor at the university, also spends time popularizing breakthroughs in his specialty — neuroscience. His book, “Welcome to Your Brain,” was named 2009 Young Adult Science Book of the Year by the American Association for the Advancement of Science. Next semester, he will offer a first for Princeton: an undergraduate course called “Neuroscience and Everyday Life.” Here is an edited version of a four-hour conversation. Q. YOU’RE ALMOST EVANGELICAL ABOUT YOUR WORK. WHY DID YOU BECOME A NEUROSCIENTIST? A. I was at Caltech in 1985, and I took a class in classical mechanics and another in introductory cell biology. And I remember asking this physics instructor about second order corrections in Lagrangian dynamics. He said, “Oh yes, that’s been thought of,” while spewing out a bunch of equations on the blackboard. I then asked my biology instructor a question about neurotransmission. He kind of smirked at me and said, “Nobody knows the answer to that.” That felt great! It was great to ask a basic question and learn the answer wasn’t known. So neuroscience seemed like the way to go. Q. AND NOW IS MORE KNOWN? A. Much more. In the 1980s, we knew some things about how individual neurons, synapses and the brain — or at least regions of it — worked. Today, we have the means to see how they work as a system, together. What has changed is advances in molecular biology, genetics and also technology. In the 1980s, the best tool for looking at neurocircuitry was to take a piece of removed tissue and look at single neurons. We now can see multiple neurons, and we can actually see how the cells talk to one another. Functional magnetic resonance imaging, F.M.R.I., lets you see what’s happening on the whole brain level. In the last three years, we’ve gotten connectomics, where people are taking a bit of tissue and mapping every connection in it. And there’s optogenetics — I’m doing a lot of that — where you express some fluorescent protein in some tissue that allows us to see individual cells and watch the change. Copyright 2010 The New York Times Company

Keyword: Evolution
Link ID: 13753 - Posted: 06.24.2010

— Only some bats and toothed whales rely on sophisticated echolocation, in which they emit sonar pulses and process returning echoes, to detect and track down small prey. Now, two new studies in the January 26th issue of Current Biology, a Cell Press publication, show that bats' and whales' remarkable ability and the high-frequency hearing it depends on are shared at a much deeper level than anyone would have anticipated -- all the way down to the molecular level. The discovery represents an unprecedented example of adaptive sequence convergence between two highly divergent groups and suggests that such convergence at the sequence level might be more common than scientists had suspected. "The natural world is full of examples of species that have evolved similar characteristics independently, such as the tusks of elephants and walruses," said Stephen Rossiter of the University of London, an author on one of the studies. "However, it is generally assumed that most of these so-called convergent traits have arisen by different genes or different mutations. Our study shows that a complex trait -- echolocation -- has in fact evolved by identical genetic changes in bats and dolphins." A hearing gene known as prestin in both bats and dolphins (a toothed whale) has picked up many of the same mutations over time, the studies show. As a result, if you draw a phylogenetic tree of bats, whales, and a few other mammals based on similarities in the prestin sequence alone, the echolocating bats and whales come out together rather than with their rightful evolutionary cousins. © 1995-2009 ScienceDaily LLC

Keyword: Hearing; Evolution
Link ID: 13752 - Posted: 06.24.2010

By Kay Lazar Roughly 8 percent of Americans ages 50 to 59 had used an illicit drug in the past year, according to a recent survey by the federal Substance Abuse and Mental Health Services Administration. Marijuana was the most commonly used, but close behind was abuse of prescription drugs, such as anti-anxiety medications, painkillers, and sleeping pills. The percentage of pot and pill abusers in this age group grew by more than 50 percent between 2002 and 2008, as more baby boomers hit 50. Now, researchers who conducted the survey worry that high rates of lifetime drug use among boomers, that massive, society-altering generation born between 1946 and 1964, is likely to create health complications for millions of aging Americans and swamp the country’s drug-treatment programs. “We are projecting that by the year 2020, we will probably have enough people in the 50-to-59 age group needing [substance abuse] treatment that we will probably need to double the number of treatment facilities,’’ said Peter Delany, the substance abuse agency’s director of the Office of Applied Studies. Delaney said that illicit drugs may cause greater impairment as users get older. “We do know,’’ he said, “that physiology slows down as you age, so the stuff processed out of your body faster when you were younger won’t be processed out so quickly when you are older.’’ © 2010 NY Times Co

Keyword: Drug Abuse
Link ID: 13751 - Posted: 06.24.2010

By BENEDICT CAREY The assorted mystics, philosophers, theologians and, most recently, neuroscientists who have burned a candle searching for the essence of consciousness all started with a simple presumption: Consciousness must begin where unconsciousness ends. Theologians have likened this state of pre-awakening to sleep, to darkness, to life underground. Modern scientists study the neural processes of sleep itself, and the transition to waking; they also have analyzed what happens in the brain when people suddenly become consciously aware of an object that was hidden in plain sight. So far, the precise neural correlates of consciousness — the brain circuits critical to “turning on” conscious awareness — have eluded capture. One reason is that consciousness itself takes many forms, from the gauzy half-dream state between the alarm clock’s bleating and sitting up; and lost stretches of waking life, as when a driver pulls into the driveway with no recollection of the half-hour commute home. The deeper that investigators dig, the more hidden chambers they find. Last Wednesday, scientists in England and Belgium reported that five people with severe brain injuries who had been identified as “vegetative,” beyond reach, showed activity on brain imaging that strongly suggested conscious awareness. One of them, a 29-year-old man thought to be “vegetative” for five years, began to answer yes and no questions by alternately showing brain activity when thinking about tennis (lighting motor areas), then about walking in his house (lighting spatial areas). Copyright 2010 The New York Times Company

Keyword: Attention; Sleep
Link ID: 13750 - Posted: 06.24.2010

Betting on the Super Bowl, roulette, or even online poker can be thrilling, and with the advent of online gambling, it's easier than ever before. Yet winning and losing can have unexpected effects on the brain that keep people coming back for more, scientists are finding. Gamblers sink an increasing sum of money into their efforts to win. Over the last 20 years legalized betting has grown tremendously; it's now a $100 billion industry. More than 65 percent of Americans gamble, according to Gallup's annual Lifestyle Poll conducted last year, and up to 5 percent of those betters develop an addiction to the activity. "For most individuals, gambling is enjoyable and harmless, but for others, it is as destructive as being addicted to drugs," said Catharine Winstanley, an assistant professor at the University of British Columbia's Department of Psychology. Story continues below ↓advertisement | your ad here Kyle Siler, a sociology doctoral student at Cornell University who studied 27 million poker hands online, told LiveScience: "Gamblers have to be honest with themselves and realize when to walk away and when a bet is profitable — even under conditions of uncertainty." Siler's study, published recently in the Journal of Gambling Studies, showed that the more hands of poker someone plays, the higher the chances that he'll walk away with smaller profits. "They might win a lot of small battles, but they're losing the war," he said, adding that people become positively reinforced with each win and more vulnerable to a crushing loss. © 2010 LiveScience.com

Keyword: Drug Abuse
Link ID: 13749 - Posted: 06.24.2010

By Jeremy Laurance, Health Editor Why are we asking this now? Scientists this week announced that they had succeeded in communicating with a man thought to be in a vegetative state, lacking all awareness, for five years following a road accident. Using a brain scanner they were able to read his thoughts and obtain yes or no answers to questions. They asked him to imagine playing tennis if he wanted to answer yes and to imagine walking through his home if he wanted to say no. By mapping the different parts of the brain activated in each case with the scanner, the scientists were able accurately record his reponses. What does this tell us about the brain? That it may still be functioning, generating thoughts and awareness, even when there is no outward sign of consciousness at all. Previously, the only way of telling if someone had any degree of consciousness was by observing how they responded to visual, auditory, tactile or noxious stimuli. If there was no response they were presumed to be in a vegetative state. In vegetative state patients, the eyes are open and they follow the normal cycle of sleeping and waking but they show no sign of being aware of their surroundings, hovering half way between consciousness and unconsciousness. In this patient, the brain scanner showed he was aware even though he showed no outward sign of being so. ©independent.co.uk

Keyword: Attention
Link ID: 13748 - Posted: 06.24.2010

By Tina Hesman Saey Sea slugs make memories with a twist. Screwing a normal nerve cell protein into a distorted shape helps slugs, and possibly people, lock in memories, new research shows. Notably, the shape change also brings a shift in the protein’s behavior, leading it to form clumps. That kind of behavior is the sort seen in prions, the misshapen, infectious proteins that cause mad cow disease, scrapie and other disorders (SN: 7/31/04, p. 67). But the new study, published February 5 in Cell, shows a possible normal function for the shape-shifting, suggesting that twists and clumps don’t necessarily make prions monsters. In one sense, prions are machines of “molecular memory,” says Yury Chernoff, a biologist at the Georgia Institute of Technology in Atlanta and editor in chief of the journal Prion. The proteins remember what happened to them — changing shapes — and then transmit that change to other proteins. “But the notion of these machines being used for cellular, and therefore organismal, memory is truly amazing,” he says. If further research shows the process works the same way in humans as it does in sea slugs, prionlike proteins might eventually be used in memory-enhancing treatments, Chernoff says. Prions have a bad reputation due to the most famous of the shape-changing proteins, called prion protein or PrP. When PrP switches from its harmless form, which is normally present in nerve cells, into a prion form, it corrupts other PrP molecules that then assemble themselves into nearly indestructible plaques known as amyloids. © Society for Science & the Public 2000 - 2010

Keyword: Prions; Learning & Memory
Link ID: 13747 - Posted: 06.24.2010