By BENEDICT CAREY The young men who opened fire at Columbine High School, at the movie theater in Aurora, Colo., and in other massacres had this in common: they were video gamers who seemed to be acting out some dark digital fantasy. It was as if all that exposure to computerized violence gave them the idea to go on a rampage — or at least fueled their urges. Social scientists have been studying and debating the effects of media violence on behavior since the 1950s, and video games in particular since the 1980s. The issue is especially relevant today, because the games are more realistic and bloodier than ever, and because most American boys play them at some point. Girls play at lower rates and are significantly less likely to play violent games. A burst of new research has begun to clarify what can and cannot be said about the effects of violent gaming. Playing the games can and does stir hostile urges and mildly aggressive behavior in the short term. Moreover, youngsters who develop a gaming habit can become slightly more aggressive — as measured by clashes with peers, for instance — at least over a period of a year or two. Yet it is not at all clear whether, over longer periods, such a habit increases the likelihood that a person will commit a violent crime, like murder, rape, or assault, much less a Newtown-like massacre. (Such calculated rampages are too rare to study in any rigorous way, researchers agree.) “I don’t know that a psychological study can ever answer that question definitively,” said Michael R. Ward, an economist at the University of Texas, Arlington. “We are left to glean what we can from the data and research on video game use that we have.” © 2013 The New York Times Company

Keyword: Aggression
Link ID: 17795 - Posted: 02.13.2013

Nearly 400 years after William Shakespeare asked, "What is love?," brain imaging studies are allowing scientists to give at least a partial answer. As our calendars get closer to Feb. 14, a day when passion is deeply associated with the heart, love will in fact be in the mind. A recent study shows love is a complex emotion triggered by 12 specific areas of the brain — the network of love. Love is in the mind, not in the heart © 1996-2013 The Washington Post

Keyword: Sexual Behavior; Emotions
Link ID: 17794 - Posted: 02.13.2013

By Laura Sanders Immune cells that help heal injuries in the adult brain may have a second job early in life, a study in mice reveals. The brain crusaders unexpectedly moonlight as sculptors, shaping a region of the brain into a male-specific form. The cells, called microglia, are mobile garbage disposals that travel around the brain and gobble up damaged cells and infectious agents. But the new study, published in the Feb. 13 Journal of Neuroscience, emphasizes that these cells have diverse functions, says neuroscientist Jean Harry of the National Institute of Environmental Health Sciences in Research Triangle Park, N.C., who was not involved in the work. Earlier results hinted that parts of the immune system have a role in building sex differences into the brain, so Kathryn Lenz and her colleagues at the University of Maryland, Baltimore decided to test whether microglia are pulling double duty. The team focused on the preoptic area of the mouse brain—“a place where you see a ton of sex differences,” Lenz says. Early in life, this brain area gets shaped by sex hormones including molecules called estradiol and prostaglandin E2, which work on the male mouse brain. In males, the preoptic area is larger, and the cells there have more elaborate shapes than in females. Scientists think those brain differences drive mating behaviors. Lenz and her colleagues found another difference in the preoptic area between males and females: Young males had about twice as many active microglia as females did. What’s more, a dose of estradiol or prostaglandin E2 in the first few days of life caused female animals to produce the male number of active microglia. © Society for Science & the Public 2000 - 2013

Keyword: Sexual Behavior; Neuroimmunology
Link ID: 17793 - Posted: 02.13.2013

by Nic Halverson By studying a magic trick that has been around for thousands of years, neuroscientists have shed light on human attention and visual systems -- as well as on the trick, itself. "Magicians, in particular, are very intellectual performance artists. They are very interested in the mind and how behavior happens," Dr. Stephen Macknik, director of the Laboratory of Behavioral Neurophysiology at the Barrow Neurological Institute(BNI), told Discovery News. "What scientists are doing when we study perception is pretty much the same thing, except we're using the scientific method." The hope is that magicians' intuitive insight could help instruct the field of neuroscience and perhaps, even be applied in medicine to help people with attention deficit issues. In their study, recently published in the inaugural issue of PeerJ, the researchers focused upon a famous trick by a pair of very famous magicians. Penn & Teller's 10-year run at The Rio All-Suite Hotel & Casino has made them one of the longest-running and most beloved acts in Las Vegas history. Their trick, "Cups and Balls," is a classic illusion performed by Roman magicians as far back as 2,000 years ago when gladiators still battled in the Colosseum. While the trick has many derivatives, the most common uses three brightly colored balls and three opaque cups. Using sleight-of-hand, the magician seemingly makes the balls pass through the bottoms of cups, jump from cup to cup, disappear and reappear elsewhere or turn into entirely different objects. In Penn & Teller's case, that different object is often a potato. © 2013 Discovery Communications, LLC. T

Keyword: Attention
Link ID: 17792 - Posted: 02.13.2013

By Scicurious When it comes down to it, most humans are pretty optimistic. Yeah, we know the Titanic sank, but our boat is better. We know that driving a car is really pretty dangerous, but we’re more careful, it won’t happen to us. This is not just a cultural thing, we generally tend to place more importance on positive information about something than on negative. We’re more optimistic than we should be on everything, from the future of our current relationship to the stock market. But what is it that makes us so optimistic? And what happens when it goes wrong? Because not everyone is optimistic. People with major depressive disorder, for example, are more pessimistic (sometimes they are just pessimistic enough to be realistic, but they can also be unrealistically pessimistic). What is it that determines how optimistic we are? It’s time to take another look at dopamine. I often talk about the neurotransmitter dopamine in the context of addiction. But dopamine is a much more subtle signal than just the “reward” or “pleasure” you see thrown around in the media. Dopamine is extremely important in detecting prediction errors: when you’ve made the wrong choice. Basically, dopamine can spike in the presence of reward, and can spike when a reward is expected. Conversely, you often see decreases in dopamine when something unexpected happens and you fail to get your reward, like with a Rickroll. That’s a prediction error, you predicted a reward and it didn’t happen. © 2013 Scientific American

Keyword: Drug Abuse; Emotions
Link ID: 17791 - Posted: 02.12.2013

By NICHOLAS BAKALAR Being physically fit in midlife is associated with a lower risk of dementia in old age, a new study reports. Between 1971 and 2009, 19,458 healthy adults younger than age 65 took a treadmill fitness test as part of a broader health examination. Researchers followed the subjects through their Medicare records for an average of 24 years. After adjusting for age, smoking, diabetes, cholesterol and other health factors, the researchers found that compared with those in the lowest 20 percent for fitness in midlife, those in the highest 20 percent had a 36 percent reduced risk of dementia. The reason for the association is unclear, but it was independent of cardiovascular and cerebrovascular risk factors for dementia, suggesting that both vascular and nonvascular mechanisms may be involved. “Dementia is a disease with no cure and no good therapies,” said the lead author, Dr. Laura F. DeFina, the interim chief scientific officer at the Cooper Institute in Dallas. Physical activity may be “a preventive way to address dementia instead of addressing the costs of a disabled elder.” The study population was largely white and highly educated, and the researchers acknowledge that their findings, published last week in The Annals of Internal Medicine, cannot be generalized to other populations. They emphasize that the study is observational and does not prove causation. Copyright 2013 The New York Times Company

Keyword: Alzheimers
Link ID: 17790 - Posted: 02.12.2013

By PAM BELLUCK A type of brain stimulation caused by a mild electric current that appears to have minimal negative side effects is showing promise as a potential treatment for major depression, according to several studies. The experimental therapy, known as transcranial direct current stimulation, or tDCS, involves a low-level charge about one-400th of that used in electroshock treatment. Unlike electroshock (also called electroconvulsive therapy or ECT), which is administered for a few seconds to patients under anesthesia, tDCS is given for 20 to 30 minutes continuously while patients are conscious. While doctors do not see it replacing electroshock, considered the most effective approach for major depression that has been treatment-resistant and requires urgent attention, tDCS does not appear to cause memory loss as electroshock can. Because it is inexpensive and easily administered, scientists say it might become an alternative or additional treatment for people whose depression is not completely helped by medication. “I think tDCS could be tried before ECT,” said Dr. Andre R. Brunoni, a psychiatrist at the University of São Paulo in Brazil and an author of a study published last week in The Journal of the American Medical Association-Psychiatry. Or, he said, it could be used “for avoiding drug treatment in patients that cannot use drugs.” Researchers said Dr. Brunoni’s study is the largest to date of about half a dozen studies in recent years. It is the first comparing tDCS with another treatment — in this case, sertraline, or Zoloft. The study, involving 120 patients, found that tDCS appeared to work about as well as a low dose of Zoloft, and that combined with Zoloft, it worked better than the drug or the stimulation alone. Zoloft and tDCS were equally safe. A few patients became manic, and some developed redness where electrodes were applied. Copyright 2013 The New York Times Company

Keyword: Depression
Link ID: 17789 - Posted: 02.12.2013

If optimists see the world through rose-colored lenses, some birds see it through ultraviolet ones. Avians have evolved ultraviolet vision quite a few times in history, a new study finds. Birds depend on their color vision for selecting mates, hunting or foraging for food, and spotting predators. Until recently, ultraviolet vision was thought to have arisen as a one-time development in birds. But a new DNA analysis of 40 bird species, reported Feb. 11 in the journal BMC Evolutionary Biology, shows the shift between violet (shorter wavelengths on the electromagnetic spectrum) and ultraviolet vision has occurred at least 14 times. "Birds see color in a different way from humans," study co-author Anders Ödeen, an animal ecologist at Uppsala University in Sweden, told LiveScience. Human eyes have three different color receptors, or cones, that are sensitive to light of different wavelengths and mix together to reveal all the colors we see. Birds, by contrast, have four cones, so "they see potentially more colors than humans do," Ödeen said. Birds themselves are split into two groups based on the color of light (wavelength) that their cones detect most acutely. Scientists define them as violet-sensitive or ultraviolet-sensitive, and the two groups don't overlap, according to Ödeen. Birds of each group would see the same objects as different hues. The specialization of color vision has its advantages. For instance, a bird with ultraviolet-sensitive vision might have spectacularly bright plumage in order to impress a female, but that same plumage might appear dull to predator birds that see only in the violet range. © 2013 Discovery Communications, LLC.

Keyword: Vision; Genes & Behavior
Link ID: 17788 - Posted: 02.12.2013

By KATHERINE BOUTON At a party the other night, a fund-raiser for a literary magazine, I found myself in conversation with a well-known author whose work I greatly admire. I use the term “conversation” loosely. I couldn’t hear a word he said. But worse, the effort I was making to hear was using up so much brain power that I completely forgot the titles of his books. A senior moment? Maybe. (I’m 65.) But for me, it’s complicated by the fact that I have severe hearing loss, only somewhat eased by a hearing aid and cochlear implant. Dr. Frank Lin, an otolaryngologist and epidemiologist at Johns Hopkins School of Medicine, describes this phenomenon as “cognitive load.” Cognitive overload is the way it feels. Essentially, the brain is so preoccupied with translating the sounds into words that it seems to have no processing power left to search through the storerooms of memory for a response. Over the past few years, Dr. Lin has delivered unwelcome news to those of us with hearing loss. His work looks “at the interface of hearing loss, gerontology and public health,” as he writes on his Web site. The most significant issue is the relation between hearing loss and dementia. In a 2011 paper in The Archives of Neurology, Dr. Lin and colleagues found a strong association between the two. The researchers looked at 639 subjects, ranging in age at the beginning of the study from 36 to 90 (with the majority between 60 and 80). The subjects were part of the Baltimore Longitudinal Study of Aging. None had cognitive impairment at the beginning of the study, which followed subjects for 18 years; some had hearing loss. Copyright 2013 The New York Times Company

Keyword: Hearing; Alzheimers
Link ID: 17787 - Posted: 02.12.2013

Philip Ball In Fiji, a star is a kalokalo. For the Pazeh people of Taiwan, it is mintol, and for the Melanau people of Borneo, bitén. All these words are thought to come from the same root. But what was it? An algorithm devised by researchers in Canada and California now offers an answer — in this case, bituqen. The program can reconstruct extinct ‘root’ languages from modern ones, a process that has previously been done painstakingly ‘by hand’ using rules of how linguistic sounds tend to change over time. Statistician Alexandre Bouchard-Côté of the University of British Columbia in Vancouver, Canada, and his co-workers say that by making the reconstruction of ancestral languages much simpler, their method should facilitate the testing of hypotheses about how languages evolve. They report their technique in the Proceedings of the National Academy of Sciences1. Automated language reconstruction has been attempted before, but the authors say that earlier algorithms tended to be rather intractable and prescriptive. Bouchard-Côté and colleagues' method can factor in a large number of languages to improve the quality of reconstruction, and it uses rules that handle possible sound changes in flexible, probabilistic ways. The program requires researchers to input a list of words in each language, together with their meanings, and a phylogenetic ‘language tree’ showing how each language is related to the others. Linguists routinely construct such trees using techniques borrowed from evolutionary biology. © 2013 Nature Publishing Group,

Keyword: Language; Evolution
Link ID: 17786 - Posted: 02.12.2013

By Tina Hesman Saey Mice are poor stand-ins for people in experiments on some types of inflammation, a new study concludes. But some scientists say that critique discounts the value of mouse studies, many of which simply couldn’t be done without the animals. More attention — and money — should go toward studying disease in people than on mouse research, a consortium of scientists contends online February 11 in the Proceedings of the National Academy of Sciences. Too often, researchers make a discovery in mice and assume that humans will react in the same way, says study coauthor Ronald Tompkins, chief of the Massachusetts General Hospital burn service. “The presumption is not justifiable,” he says. As a result, drug trials — often based heavily on data gleaned from studies with mice — can fail. But other scientists say that critique isn’t new and is overstated. Clinical trials are unsuccessful for many reasons, says Derry Roopenian, an immunologist and mouse geneticist at the Jackson Laboratory in Bar Harbor, Maine. “There’s frailty all along the process. That’s not a failure of the mouse.” He and other critics worry that the study, conducted with a generic strain of laboratory mouse called Black6, unfairly tarnishes the reputation of all mice, even ones engineered to be as much like humans as possible. The group’s conclusions, were they accepted by policy makers, could set back biomedical research by jeopardizing funding for mouse studies, critics warn. “Without the mouse, progress is going to be slowed to a standstill,” Roopenian says. © Society for Science & the Public 2000 - 2013

Keyword: Animal Rights
Link ID: 17785 - Posted: 02.12.2013

By JANE E. BRODY “Treatment is not a prerequisite to surviving addiction.” This bold statement opens the treatment chapter in a helpful new book, “Now What? An Insider’s Guide to Addiction and Recovery,” by William Cope Moyers, a man who nonetheless needed “four intense treatment experiences over five years” before he broke free of alcohol and drugs. As the son of Judith and Bill Moyers, successful parents who watched helplessly during a 15-year pursuit of oblivion through alcohol and drugs, William Moyers said his near-fatal battle with addiction demonstrates that this “illness of the mind, body and spirit” has no respect for status or opportunity. “My parents raised me to become anything I wanted, but when it came to this chronic incurable illness, I couldn’t get on top of it by myself,” he said in an interview. He finally emerged from his drug-induced nadir when he gave up “trying to do it my way” and instead listened to professional therapists and assumed responsibility for his behavior. For the last “18 years and four months, one day at a time,” he said, he has lived drug-free. “Treatment is not the end, it’s the beginning,” he said. “My problem was not drinking or drugs. My problem was learning how to live life without drinking or drugs.” Mr. Moyers acknowledges that treatment is not a magic bullet. Even after a monthlong stay at a highly reputable treatment center like Hazelden in Center City, Minn., where Mr. Moyers is a vice president of public affairs and community relations, the probability of remaining sober and clean a year later is only about 55 percent. Copyright 2013 The New York Times Company

Keyword: Drug Abuse
Link ID: 17784 - Posted: 02.11.2013

Steve Connor Scientists believe they may be able to discover why children who spend much of their time indoors rather than playing outside are more likely to develop short-sightedness following a breakthrough study into the genetics of myopia. More than two dozen genes have been linked to an increased risk of developing myopia, a finding that may finally allow researchers to understand why children today are more likely to become short-sighted than children in the past. Myopia now affects about one in three people in the West and up to 80 per cent of people in Asia. In some countries in the Far East as many as 90 per cent of children are short-sighted, compared to less than 20 per cent a couple of decades ago. Although short-sightedness tends to run in families and has a strong inherited component, the explosive increase in the condition over recent years has been linked with an increase in the time that children spend indoors either studying or playing computer games and watching TV, scientists believe. A study of more than 45,000 people from Europe and Asia has identified 24 new genes that appear to be involved in triggering the onset of myopia. It has also confirmed the role of two further genes that were already suspected of being involved with short-sightedness, the scientists said. © independent.co.uk

Keyword: Vision; Genes & Behavior
Link ID: 17783 - Posted: 02.11.2013

By Laura Sanders Psychiatry seemed poised on the edge of a breakthrough. In early 2011, after decades of no radically new drugs, a fundamentally different schizophrenia treatment promised relief from the psychotic hallucinations and delusions plaguing people with the disease. The new compound, devised by chemists at Eli Lilly and Co., hit a target in the brain that older medicines had ignored. All signs pointed to success. In mice, a similar molecule could block the schizophrenia-like effects of PCP. In people the new drug, LY2140023, appeared to curb psychotic behavior with few side effects, small pilot studies showed. In March 2011, Lilly began enrolling 1,100 people in a definitive Phase III clinical trial, the final test designed to show conclusively that the new compound worked. A year and a half later, the drug was dead. After years of work and millions of dollars of investment, the failure was crushing. People with schizophrenia were no better on the new drug than similar people taking a placebo, early results indicated. “I’m disappointed in what these results mean for patients with schizophrenia who still are searching for options to treat this terrible illness,” Jan Lundberg, president of Lilly Research Laboratories, said in a press release. Although the results were devastating, many in the field weren’t surprised. For new drugs designed to treat complex brain disorders such as schizophrenia, depression and anxiety, the odds of success are exceedingly slim. Given the current state of affairs in the drug discovery world, some would argue those odds are close to zero. Not a single drug designed to treat a psychiatric illness in a novel way has reached patients in more than 30 years, argues psychiatrist Christian Fibiger of the University of British Columbia in Kelowna, who described the problem in a 2012 Schizophrenia Bulletin editorial. “For me, the data are in,” says Fibiger, who has developed drugs at several major pharmaceutical companies. “We’ve got to change. This isn’t working.” © Society for Science & the Public 2000 - 2013

Keyword: Schizophrenia; Depression
Link ID: 17782 - Posted: 02.11.2013

by Michael Marshall Humans aren't built for giving birth. Babies' heads are big to accommodate their big brains, but the mother's hips are small because they walk upright. As a result, birth takes hours and is extremely painful – and midwives almost always help out. Other animals may find birth difficult, particularly if the babies have been gestating for a long time and have grown large. Nevertheless, most mammals have it easier than humans. Monkeys give birth in less than ten minutes. So it is a surprise that female black snub-nosed monkeys may be assisted by "midwives" when they give birth. This behaviour has only been seen once in this species, but it suggests that it's not just human mothers that need help giving birth. Black snub-nosed monkeys live in societies called bands, which can be over 400 strong. Each is divided into smaller groups of around 10 monkeys. Most groups contain one male and several females plus offspring, but there are also all-male groups. Wen Xiao of Dali University in Yunnan, China, and colleagues have been observing black snub-nosed monkeys in the province for years, but had never seen one give birth: the monkeys normally deliver at night. Then on 18 March last year, they got lucky. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 17781 - Posted: 02.11.2013

By James Gallagher Health and science reporter, BBC News It may be possible to use a patient's own skin to repair the damage caused by multiple sclerosis (MS), which is currently incurable, say researchers. Nerves struggle to communicate in MS as their insulating covering is attacked by the immune system - causing fatigue and damaging movement. Animal tests, described in the journal Cell Stem Cell, have now used modified skin cells to repair the insulation. Experts said there was an "urgent need" for such therapies. Just like electrical wires, nerves have insulation - but instead of plastic, the body uses a protein called myelin. However, diseases that result in damage to the myelin, including MS, leave the nerves exposed and electrical signals struggle to travel round the body. A team of scientists at the University of Rochester Medical Center, in the US, used advances in stem-cell research to attempt to repair the myelin. They took a sample of human skin cells and converted it into stem cells, which are capable of becoming any other type of cell in the body. The next step was to transform the stem cells into immature versions of cells in the brain that produce myelin. When these cells had been injected into mice born without any myelin it had had a significant effect, said researchers. BBC © 2013

Keyword: Multiple Sclerosis; Stem Cells
Link ID: 17780 - Posted: 02.09.2013

by Carrie Arnold If you want to survive as an ant, you'd better get ready to make some noise. A new study shows that even ant pupae—a stage between larvae and adult—can communicate via sound, and that this communication can be crucial to their survival. "What's very cool about this paper is that researchers have shown for the first time that pupae do, in fact, make some sort of a sound," says Phil DeVries, an entomologist at the University of New Orleans in Louisiana who was not involved in the study. "This was a very clever piece of natural history and science." Scientists have known for decades that ants use a variety of small chemicals known as pheromones to communicate. Perhaps the most classic example is the trail of pheromones the insects place as they walk. Those behind them follow this trail, leading to long lines of ants marching one by one. However, the insects also use pheromones to identify which nest an ant is from and its social status in that nest. Because this chemical communication is so prevalent and complex, researchers long believed that this was the primary way ants shared information. However, several years ago, researchers began to notice that adults in some ant genuses, such as Myrmica, which contains more than 200 diverse species found across Europe and Asia, made noise. These types of ants have a specialized spike along their abdomen that they stroke with one of their hind legs, similar to dragging the teeth of a comb along the edge of a table. Preliminary studies seemed to indicate that this noise served primarily as an emergency beacon, allowing the ants to shout for help when being threatened by a predator. © 2010 American Association for the Advancement of Science

Keyword: Animal Communication; Language
Link ID: 17779 - Posted: 02.09.2013

The use of an advanced imaging shortly after the onset of acute stroke failed to identify a subgroup of patients who could benefit from a clot-removal procedure, a study has found. The randomized controlled trial known as Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE) was funded by the National Institute of Neurological Disorder and Stroke (NINDS), part of the National Institutes of Health, and was published online Feb. 8 in the New England Journal of Medicine. In patients with ischemic stroke (caused by a blockage in an artery), brain cells deprived of blood die within minutes to hours. Rapidly opening the artery can halt brain cell death. Intravenous tissue plasminogen activator (t-PA), a drug that dissolves clots has been shown to improve outcomes in such stroke patients. However intravenous t-PA is not effective in many patients with large clots blocking the major brain arteries that cause the most devastating strokes. MR RESCUE investigators tested an invasive clot removal strategy designed to remove clots from these large arteries. Patients in the study were enrolled at 22 centers in the United States within approximately 5.5 hours of their stroke onset. Their ability to function independently was assessed at 90 days. All MR-RESCUE patients underwent emergency computed tomography (CT) or magnetic resonance (MRI) perfusion imaging to identify regions of the brain with decreased blood flow, as well as regions that could not be salvaged.

Keyword: Stroke; Brain imaging
Link ID: 17778 - Posted: 02.09.2013

By JAMES DAO Over the past decade, about half a million veterans have received diagnoses of post-traumatic stress disorder or traumatic brain injury. Thousands have received both. Yet underlying the growing numbers lies a disconcerting question: How many of those diagnoses are definitive? And how many more have been missed? A series of articles and videos chronicling the experiences of military veterans who have returned from Iraq and Afghanistan but continue to confront the medical and psychological scars of battle. No one can say. Though PTSD is hardly new, diagnoses still largely rely on self-reported symptoms. And while severe brain injuries are often clearly diagnosable, finding evidence of mild T.B.I.’s, particularly older ones, can be all but impossible. It means that for a soldier who, five years after duty in Iraq, still feels “not right,” with symptoms from headaches to sleeping problems to irritability, doctors can only guess at the cause. Maybe PTSD. Maybe T.B.I. Maybe both. Now, in one of the largest studies of its kind, a team of researchers based out of New York University’s medical school have begun a five-year study to find biological signals, known as biomarkers, that could provide reliable, objective evidence of those so-called invisible injuries of war. © 2013 The New York Times Company

Keyword: Stress; Brain imaging
Link ID: 17777 - Posted: 02.09.2013

by Emily Underwood Globs of protein clustered in the neurons that control muscles have long been the hallmark of amyotrophic lateral sclerosis (ALS), the fatal neurodegenerative disease also commonly known as Lou Gehrig's disease. Now, a study of the most commonly found mutant gene in people with ALS reveals an unexpected origin of some of those sticky masses, a finding that may offer drug developers a new target for treatments. Located on the ninth chromosome, which explains part of its unwieldy name, the C9orf72 gene has a bit of a stutter. A typical version in healthy people contains a stretch of DNA where a string of six genetic letters—GGGGCC—repeats up to 25 times. Scientists have recently found that in a sizable share of people with ALS and frontotemporal dementia (FTD), a less common neurological disease characterized by language, memory, and emotional problems, this repeat occurs many more times; some people have thousands of copies. Since these C9orf72 mutations were discovered in 2011, some researchers have speculated that the repeats interrupt production of the gene's normal protein, which serves some as-yet unknown, but vital function in motor neurons or other brain cells. Others have hypothesized that the mutation spawns a large, misshapen strand of RNA that grabs on to proteins such as TDP-43, which normally help process RNA, creating protein tangles that starve the cell of the machinery it needs to function. © 2010 American Association for the Advancement of Science

Keyword: ALS-Lou Gehrig's Disease
Link ID: 17776 - Posted: 02.09.2013