Mutations in a single gene are the cause of a rare genetic disorder that leaves children with a brain one-tenth the normal size, two international teams of researchers report April 28 in the American Journal of Human Genetics. To identify the mutations, researchers analyzed DNA from Turkish, Pakistani and Saudi Arabian families with children who had extremely underdeveloped brains. Affected children had mutations in a gene called NDE1, both groups found. Cells without a working copy of the gene don’t correctly divide to form new cells, a defect that probably prevents the brain from growing normally in early development. Further studies of the gene might reveal clues to how humans evolved large brains, the researchers speculate. —Laura Sanders © Society for Science & the Public 2000 - 2011

Keyword: Development of the Brain; Genes & Behavior
Link ID: 15279 - Posted: 04.30.2011

By THE NEW YORK TIMES If a young child suddenly stops speaking, is autism to blame? That is among the questions recently posed by readers of the Consults blog. Here, Dr. Fred Volkmar, director of the Yale Child Study Center, explores the issue of regression in children and the diagnosis of autism. For more information on autism, see the additional responses in “Ask the Experts About Autism,” and The Times Health Guide: Autism. The issue of loss of skills, or regression, in children with autism is an interesting and complicated area. Dr. Leo Kanner, a pioneer of child psychiatry, had first described autism as a congenital condition that children are born with. Fairly shortly thereafter, though, some clinicians noted that about 20 percent of the time, parents said that a child would seem to develop normally but then lose skills. Subsequent work has generally confirmed this figure, more or less, but for several reasons, we still don’t understand the phenomenon or its significance. For one thing, the earliest signs of autism can be somewhat subtle. These signs become more numerous as children get past their first birthday. That’s one reason that screening tests for autism focus on children ages 18 to 24 months, when there are more things to look for. In addition, parents can vary tremendously in how sophisticated they are as observers. Studies suggest that if you use parents’ reports about their children as the primary way to classify regression, results can be unreliable. A few years ago, a medical student worked with me and went over hundreds of cases of children with autism and other problems, looking for parents’ reports of regression, but also looking at reports of early milestones and other possible early warning signs. The number of cases of regression were about what we expected, but there were several interesting findings. © 2011 The New York Times Company

Keyword: Autism
Link ID: 15278 - Posted: 04.30.2011

By Rob Stein, Pediatricians could diagnose children with autism earlier by asking parents to fill out a simple, five-minute checklist when they take their babies in for their first-year checkups, according to research released Thursday. The federally funded study involving more than 10,000 infants found that the questionnaire appeared to identify about half of children who eventually would be diagnosed with the brain disorder. Early diagnosis would allow doctors to treat children with autism sooner, when therapy appears to be much more effective. By allowing scientists to study children with autism when they are younger, it could also provide crucial new insights into the disease’s causes, further dispelling discredited theories about vaccines and other supposed risk factors, as well as leading to better ways to diagnose and treat the disorder. “This study is enormously important from the practical standpoint of helping families out,” said Karen Pierce of the University of California at San Diego, who led the research. “And from a scientific standpoint, it is undeniably important because for the first time you can study autism before the full-blown symptoms come on line.” More than 36,000 children are diagnosed each year in the United States with autism spectrum disorder, a condition marked by social, communication and behavioral problems. Most are not identified until about age 5. Researchers have been trying to find the signs in younger children in order to start intensive therapy sooner and try to minimize abnormal behaviors.

Keyword: Autism
Link ID: 15277 - Posted: 04.30.2011

Virginia Gewin The closed eyes, the unresponsiveness, the drool — sleep is an easily recognizable, all-encompassing state. But the divide between sleep and wakefulness may not be as clearcut as we thought. Research published today in Nature demonstrates that in visibly awake rats, neurons in some areas of the brain's cortex briefly go 'offline'. In these pockets, neuronal patterns resemble those associated with non-rapid eye movement (NREM) sleep1. "The rats were awake, but awake with a nice sprinkling of localized sleep in the cortex," says Guilio Tononi, a neuroscientist at the University of Wisconsin–Madison and lead author of the study. The team used different techniques to measure both the local and global electric field potentials in the brain. Localized neural activity was measured using microwire arrays implanted deep in the frontal and parietal cortex field, whereas electroencephalography (EEG) detects global neuronal activity such as slow waves seen in NREM sleep. During slow-wave activity, neurons oscillate between ON and OFF states, but are typically OFF. By recording the activity of many small populations of neurons, Tononi and his colleagues showed that OFF states occur randomly throughout the cortex when a rat has been awake for a long time. "If we could watch the whole brain, it would be like watching boiling water - when you are awake, just before boiling, all the neurons are ON. As the animal gets tired, the OFF periods would then be the bubbles; where they appear is impossible to predict," he says. © 2011 Nature Publishing Group,

Keyword: Sleep
Link ID: 15276 - Posted: 04.28.2011

by Helen Fields The battle of the sexes has just heated up—in dogs. A new study finds that when a ball appears to magically change size in front of their eyes, female dogs notice but males don't. The researchers aren't sure what's behind the disparity, but experts say the finding supports the idea that—in some situations—male dogs trust their noses, whereas females trust their eyes. The study, published online today in Biology Letters, didn't set out to find sex differences. Cognitive biologist Corsin Müller and his colleagues at the University of Vienna and its Clever Dog Lab wanted to find out how good dogs are at size constancy—the ability to recognize that an object shouldn't change size if it disappears for a moment. But they recruited 25 female and 25 male dogs for the study, just to be safe. When a dog came to the lab for the test, first it got to play with two balls: one the size of a tennis ball and one that looked identical but was about the size of a cantaloupe. Then the dog and owner left the room while a researcher set up the experiment. When the dog came back, it sat in front of its owner, who was blindfolded so that his or her reactions wouldn't influence the pet. One of the balls sat to the left of a screen in front of the dog, and an experimenter, hiding behind another screen, slowly pulled the ball with transparent string. As the dog watched, the ball went behind the screen. Then the ball reappeared on the other side. But in some cases, it was replaced by the other ball, so the ball seemed to have magically shrunk or grown (see video). © 2010 American Association for the Advancement of Science

Keyword: Sexual Behavior; Attention
Link ID: 15275 - Posted: 04.28.2011

Babies born in spring are slightly more likely to develop anorexia nervosa, while those born in the autumn have a lower risk, say researchers. A report published in the British Journal of Psychiatry suggests temperature, sunlight, infection or the mother's diet could be responsible. Other academics said the effect was small and the disorder had many causes. The researchers analysed data from four previous studies including 1,293 people with anorexia. The researchers found an "excess of anorexia nervosa births" between March and June - for every seven anorexia cases expected, there were in fact eight. There were also fewer than expected cases in September and October. Dr Lahiru Handunnetthi, one of the report's authors, at the Wellcome Trust Centre for Human Genetics, said: "A number of previous studies have found that mental illnesses such as schizophrenia, bipolar disorder and major depression are more common among those born in the spring - so this finding in anorexia is perhaps not surprising. "However, our study only provides evidence of an association. Now we need more research to identify which factors are putting people at particular risk." The report suggests seasonal changes in temperature, sunlight exposure and vitamin D levels, maternal nutrition and infections as "strong candidate factors". BBC © 2011

Keyword: Anorexia & Bulimia; Biological Rhythms
Link ID: 15274 - Posted: 04.28.2011

By Bruce Bower Right-handedness reaches back a half million years in the human evolutionary family, at least if scratched-up fossil teeth have anything to say about it. Stone-tool scratches on the front teeth of Neandertals and their presumed European ancestors occur at angles denoting right-handedness in most of these Stone Age hominids, just as in human populations today, say anthropologist David Frayer of the University of Kansas in Lawrence and his colleagues. Scientists have linked prevalent right-handedness in human populations to a left brain hemisphere that controls right-sided body movements and enables critical language functions. Given the new tooth evidence, populations of largely right-handed Neandertals and their predecessors must have possessed a gift for gab, Frayer’s team proposes in a paper published online April 14 in Laterality. “Findings so far suggest that most European hominids were right-handed by at least 500,000 years ago,” Frayer says. “A capacity for language appears to have ancient, not recent, roots.” Along with widespread right-handedness indicating that these ancient hominids possessed language-ready brains, humanlike inner-ear fossils show that Neandertals’ ancestors could hear all the sounds employed in modern tongues, Frayer asserts. Other researchers contend that, based on vocal-tract reconstructions informed by skull and upper-body fossils, Neandertals were physically incapable of articulating some modern speech sounds. In these scientists’ view, language as spoken today originated in Homo sapiens sometime after 200,000 years ago. © Society for Science & the Public 2000 - 2011

Keyword: Laterality; Evolution
Link ID: 15273 - Posted: 04.28.2011

People taking a widely used class of antidepressants known as SSRIs may find the benefits of the medication cancelled out when they also take painkillers such as ibuprofen, scientists say. The findings from experiments in mice can't prove that drugs such as ibuprofen and Aspirin — known as non-steroidal anti-inflammatory drugs, or NSAIDs — stop antidepressants from working, the researchers said. But the possible effect is worth considering, since a similar effect was found analyzing data from a human study, the researchers say in this week's online issue of the Proceedings of the National Academy of Sciences, or PNAS. NSAID painkillers may prevent a class of antidepressants from working effectively.NSAID painkillers may prevent a class of antidepressants from working effectively. iStock "Analysis of our clinical data strongly suggests that remission rates among depressed individuals may be improved by avoiding certain common over-the-counter medications," Paul Greengard of Rockefeller University in New York and his co-authors wrote. Mice treated with an SSRI antidepressant behaved differently when they were also given the anti-inflammatory painkillers, scientists found. The animals performed worse on tests measuring their stress and depression than those that took just the antidepressant. Tests showed mice treated with the antidepressant citalopram and an NSAID also had lower levels of the antidepressant in their blood than those taking the antidepressant alone. © CBC 2011

Keyword: Depression; Pain & Touch
Link ID: 15272 - Posted: 04.28.2011

By Jennifer Viegas The brainier a bird is, the better its chances are of thriving in a city, according to a new study that found many big-brained birds can succeed in urban environments. "Big" in this case refers to brain size relative to body size. In other words, the larger the ratio of brain to body, the more likely the bird will thrive in an urban environment. "Species with relatively larger brains tend to have broader diets, live in diverse habitats and have a higher propensity for behavioral innovations in foraging," lead author Alexei Maklakov told Discovery News. "They are better able to establish viable populations when introduced to new habitats by humans." Maklakov, a researcher in the Department of Animal Ecology at Uppsala University, and his colleagues studied how well -- or not -- 82 species of passerine birds belonging to 22 avian families did in and around a dozen cities in France and Switzerland. Bird species that were able to breed in city centers were considered successful colonizers. Birds that bred around the cities, but not in the urban regions themselves, were considered to be urban avoiders. For the study, which is published in the latest issue of Royal Society Biology Letters, the scientists also looked at the brain size and body mass of each bird. The researchers determined that the following are brainy birds that do well in cities: the great tit, the blue tit, the carrion crow, the jackdaw, the magpie, the nuthatch, the wren, the long-tailed tit and more. Pigeons are not passerines, so these ubiquitous urban dwellers were not included in the study. © 2011 Discovery Communications, LLC.

Keyword: Intelligence; Evolution
Link ID: 15271 - Posted: 04.28.2011

By Nina Bai Recovering addicts are often told to avoid the people, places, and things connected with their addiction—tried-and-true advice that may be gaining support from neuroscience. A view widely accepted among addiction researchers is that drug abuse can cause the brain to form persistent, enduring associations between a drug and the environment in which it is purchased and consumed. These mental ties represent a subconscious form of learning and contribute to the tenacious grip of addictions. "There's a growing consensus in the addiction field that addiction is a learning and memory disorder. We learn behavior associated with these drugs too well." says Hitoshi Morikawa, a neurobiologist at the University of Texas at Austin. New research from Morikawa's lab, published April 6 in the Journal of Neuroscience, found that repeated use of alcohol can make the brain more susceptible to forming reward-based associations. Mice given a weeklong binge of alcohol were more likely to remember the environment in which they later received cocaine. In human addicts similar associations could explain why certain environments are apt to trigger relapse. Addictive drugs cause dopamine neurons, which synthesize and store the neurotransmitter dopamine, to release it, signaling to other brain areas to take note of the context surrounding the drug—the better to replicate the experience in the future. "We can think of those neurons that release dopamine as 'teachers' that tell other brain areas, the 'students,' to learn the associations surrounding rewards such as food, sex and addictive drugs," Morikawa explains. In essence, alcohol and other addictive drugs help the "teachers" teach better. © 2011 Scientific American,

Keyword: Drug Abuse; Learning & Memory
Link ID: 15270 - Posted: 04.28.2011

By Bonnie Berkowitz, Black coffee. Hot peppers. Truffles. Oysters. The world is full of polarizing flavors and foods, beloved by many, despised by just as many. Why is that? Scientists have untangled some — but not nearly all — of the mysteries behind our love and hatred of certain foods. While we might say, “That tastes like strawberry,” scientists who study these things would disagree. Our tongues actually perceive only five basic tastes: sweet, sour, bitter, salty and “umami,” the Japanese word for savory. To go from merely sweet to “Mmm, strawberry!” the nose has to get involved. The taste and olfactory senses, along with any chemical irritation a food creates in the throat (think mint, hot pepper or olive oil), all send the brain the information it needs to distinguish flavors. “We as primates are born liking sweet and disliking bitter,” said Marcia Pelchat, who studies food preferences at the Monell Chemical Senses Center in Philadelphia. The theory is that we’re hard-wired to like and dislike certain basic tastes so that the mouth can act as the body’s gatekeeper. Sweet means energy; sour means not ripe yet. Savory means food may contain protein. Bitter means caution, as many poisons are bitter. Salty means sodium, a necessary ingredient for several functions in our bodies. (By the way, those tongue maps that show taste buds clumped into zones that detect sweet, bitter, etc.? Very misleading. Taste receptors of all types blanket our tongues — except for the center line — and some reside elsewhere in our mouths and throats.)

Keyword: Chemical Senses (Smell & Taste)
Link ID: 15269 - Posted: 04.28.2011

by Michael Balter Kids who score higher on IQ tests will, on average, go on to do better in conventional measures of success in life: academic achievement, economic success, even greater health, and longevity. Is that because they are more intelligent? Not necessarily. New research concludes that IQ scores are partly a measure of how motivated a child is to do well on the test. And harnessing that motivation might be as important to later success as so-called native intelligence. Researchers have long debated what IQ tests actually measure, and whether average differences in IQ scores--such as those between different ethnic groups--reflect differences in intelligence, social and economic factors, or both. The debate moved heavily into the public arena with the 1994 publication of The Bell Curve by Richard Herrnstein and Charles Murray, which suggested that the lower average IQ scores of some ethnic groups, such as African-Americans and Hispanics, were due in large part to genetic differences between them and Caucasian groups. That view has been challenged by many scientists. For example, in his 2009 book "Intelligence and How to Get It," Richard Nisbett, a psychologist at the University of Michigan, Ann Arbor, argued that differences in IQ scores largely disappear when researchers control for social and economic factors. New work, led by Angela Lee Duckworth, a psychologist at the University of Pennsylvania, and reported online today in the Proceedings of the National Academy of Sciences explores the effect of motivation on how well people perform on IQ tests. While subjects taking such tests are usually instructed to try as hard as they can, previous research has shown that not everyone makes the maximum effort. A number of studies have found that subjects who are promised monetary rewards for doing well on IQ and other cognitive tests score significantly higher. © 2010 American Association for the Advancement of Science.

Keyword: Intelligence; Emotions
Link ID: 15268 - Posted: 04.26.2011

By NICHOLAS BAKALAR If a blind person were suddenly able to see, would he be able to recognize by sight the shape of an object he previously knew only by touch? Presented with a cube and a globe, could he tell which was which just by looking? The question goes to the heart of a problem in the philosophy of mind: Is there an innate conception of space common to both sight and touch, or do we learn that relationship only through experience? Research published online April 10 in the journal Nature Neuroscience may have finally answered the question, which has vexed philosophers and scientists for more than 300 years. William Molyneux, an Irish politician and scientist, first raised the issue in a letter to John Locke in 1688. Locke took up what came to be known as Molyneux’s problem in “An Essay Concerning Human Understanding,” published a few years later. Locke’s answer was no. “He would not be able with certainty to say which was the globe, which the cube, whilst he only saw them,” he wrote, “though he could unerringly name them by his touch.” For Locke, the connection between the senses was learned. Dozens of philosophers have since considered the problem, among them George Berkeley, Gottfried Leibniz, Voltaire, Diderot, Adam Smith and William James. And some efforts have been made to answer the question experimentally, beginning in the early 18th century with studies of patients whose congenital cataracts had been removed in adulthood and continuing recently in observations of newborns. © 2011 The New York Times Company

Keyword: Development of the Brain; Vision
Link ID: 15267 - Posted: 04.26.2011

By ABBY ELLIN Dr. Suzanne Dooley-Hash believes that she will never fully recover from the anorexia that has plagued her since she was 15 years old. For many years, she did not take laxatives constantly to lose weight, as she did in the mid-1980s, and her health was “relatively O.K.” Thoughts about her weight did not occupy every second of every minute of every day. But in 2005 she relapsed, losing one-third of her body weight in six months. She took off 19 months from her job as an emergency room physician at the University of Michigan Medical School in Ann Arbor to devote herself to getting her life back in order. Like many patients with eating disorders, however, she is not sure what recovery means. “Does it mean ‘functional?’ ” asked Dr. Dooley-Hash, 45. “I’m a physician at a really high-powered institution, and I’ve published in well-respected journals — I’m functional. I don’t think functionality is necessarily a good measure.” Dr. Dooley-Hash is not alone in her confusion. Most medical experts agree that a third of people with the disorder will remain chronically ill, a third will die of their disorder, and a third will recover — with one significant caveat. There is surprisingly little agreement as to what “recovery” means for people with anorexia. Indeed, just a handful of studies on long-term recovery rates have been conducted over the last decade or so, and different parameters were used in each one. © 2011 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 15266 - Posted: 04.26.2011

By ABIGAIL ZUGER, M.D. If there’s anything I can’t stand, it’s somebody kicking the back of my chair. That, and the public clipping of fingernails. And loud gum chewing. Oh yes, and the neighbors’ muffled stereo, and people who are habitually late, and there are actually 20 or 30 other little problems I have with the world at large. But now on to you. You get every bit as annoyed as I do by car alarms that never stop, fingernails screeching down blackboards, and a fly buzzing around your head. The prolonged whining of a child, your own or somebody else’s, drives you crazy. In other words, some annoyances are particular to the individual, some are universal to the species, and some, like the fly, appear to torture all mammals. If ever there was a subject for scientists to pursue for clues to why we are who we are, this is the one. And yet, as Joe Palca and Flora Lichtman make clear in their immensely entertaining survey, there are still more questions than answers in both the study of what annoys people and the closely related discipline of what makes people annoying. Mr. Palca and Ms. Lichtman — he is a science correspondent for National Public Radio and she an editor for the network’s “Science Friday” program — skitter all over the map in pursuit of their subject, and at first their progress seems peculiarly random, like one of those robotic vacuums. But in the end they do indeed cover every part of the terrain: from physics and psychology to aesthetics, genetics and even treatment for the miserably, terminally annoyed. © 2011 The New York Times Company

Keyword: Emotions
Link ID: 15265 - Posted: 04.26.2011

By Daniel Strain Fire ants know how to survive when the waters rise: They turn their bodies into life rafts. A new study explores the physics that keeps fire ant lifeboats, waterborne colonies sometimes containing tens of thousands of bugs, afloat. Linked together, the ants can form a watertight seal that keeps them from drowning, engineers from the Georgia Institute of Technology in Atlanta report the week of April 25 in the Proceedings of the National Academy of Sciences. And the whole is bigger than the sum of its parts, says Julia Parrish, a zoologist at the University of Washington in Seattle: "The properties the group displays are not necessarily predictable by just looking at one individual." Fire ants (Solenopsis invicta), an invasive species around much of the globe, are well-prepared for disaster. When their Brazilian homes flood, entire colonies — including queens, workers and workers carrying larvae — take to the sea. "They have to stay together as a colony to survive," says study coauthor Nathan Mlot of Georgia Tech. Their double-decked rafts — about half the ants float on the bottom holding the rest up — can bob along for days or even weeks. The ants' seafaring success comes down to both small and big properties. On the small scale, single ants can walk on water, at least to a degree, similar to a floating pin or a water-striding insect. When wet, fire ants can also capture tiny air bubbles, probably thanks to the thin layers of hair covering their bodies, giving these intrepid mariners added buoyancy. © Society for Science & the Public 2000 - 2011

Keyword: Miscellaneous
Link ID: 15264 - Posted: 04.26.2011

By Sandra G. Boodman, During the 11 years Sonja MacDonald and her family lived with her spells, they had planned what to do when she sensed — or they observed — one coming on. If she was driving, MacDonald was to pull over to the side of the road; her husband had taught their young children how to take the wheel if she was unable to steer, something that luckily never happened. When she took a shower, someone was always in the bathroom, in case she suddenly passed out. And if it happened in the nursing home where she worked, MacDonald gambled on being able to make it to an empty bed. Over the years doctors had given the Milton, Pa., resident various diagnoses for the episodes, which she said began with an aura — an odd feeling of disorientation sometimes tinged with fear. She would stare blankly, sometimes grasping at unseen objects or briefly losing consciousness. These incidents, which lasted two minutes at most, occurred without warning, leaving her feeling tired and cold but with no memory of what had just happened. Most specialists agreed that the spells were seizures that sometimes follow a migraine headache. But how, MacDonald wondered, could she have migraine seizures when the occasional headaches she had were not severe? Doctors brushed that question aside, and MacDonald resigned herself to living with whatever was wrong. “I told my husband, ‘I will not go back to another doctor. I guess when I drop over someone will believe me,’ ” said MacDonald, now 39. In 2009, a new neurologist took a fresh look at her case and in short order figured out what was wrong. The answer, this doctor subsequently learned, had been buried in MacDonald’s records for years.

Keyword: Epilepsy; Pain & Touch
Link ID: 15263 - Posted: 04.26.2011

by Carl Zimmer One day not long ago a 27-year-old woman was brought to the 
Tel Aviv Sourasky Medical Center, sleepy and confused. Fani Andelman, a neuropsychologist at the center, and colleagues gave the woman a battery of psychological tests to judge her state of mind. At first the woman seemed fine. She could see and speak clearly. She could understand the meaning of words and recall the faces of famous people. She could even solve logic puzzles, including a complex test that required her to plan several steps ahead. But her memory had holes. She could still remember recent events outside her own life, and she could tell Andelman details of her life up to 2004. Beyond that point, however, her autobiography was in tatters. The more doctors probed her so-called episodic memory—the sequential recollection of personal events from the past—the more upset she became. As for envisioning her personal future, that was a lost cause. Asked 
what she thought she might be doing anytime beyond the next day, she couldn’t tell them anything at all. The patient, Andelman realized, hadn’t just lost her past; she had lost her future as well. It was impossible for her to imagine traveling forward in time. During her examination, the woman offered an explanation for her absence of foresight. “I barely know where I am,” she said. “I don’t picture myself in the future. I don’t know what I’ll do when I get home. You need a base to build the future.” The past and future may seem like different worlds, yet the two are intimately intertwined in our minds. In recent studies on mental time travel, neuroscientists found that we use many of the same regions of the brain to remember the past as we do to envision our future lives. In fact, our need for foresight may explain why we can form memories in the first place. They are indeed “a base to build the future.” And together, our senses of past and future may be crucial to our species’ success. © 2011, Kalmbach Publishing Co.

Keyword: Learning & Memory
Link ID: 15262 - Posted: 04.26.2011

By Daryl Shorter, MD and Thomas R. Kosten, MD Substance use disorders (SUD) are recognized worldwide as causes of negative medical, psychological, and social outcomes, and they result in significant personal consequences for affected persons, their families, and society at large. Treatment of SUD has focused on a combination of pharmacotherapy and behavioral therapies in an effort to improve patients’ chances of successfully entering and maintaining recovery. Antidrug vaccines are a potentially important class of medications currently under investigation. They represent yet another frontier in the ongoing quest for novel pharmacological strategies that could be easily integrated into treatment plans to reduce substance use and establish abstinence. Ultimately, these vaccines reflect an important shift in our conceptualization of drugs of abuse, ie, that these substances are “foreign” and that the body’s own defenses can be used against them. Drugs of abuse act centrally on the reward and reinforcement pathways of the brain. After introduction into the body, via oral, intranasal, inhalation, or intravenous route, these substances rapidly enter the brain to activate target neurotransmitter systems. One factor of particular importance in addiction pharmacology relates to the size of the molecule, because substances of abuse must be small enough to traverse the blood-brain barrier. Once in the brain, the initial common pathway of the addictive process is through stimulation of dopamine(Drug information on dopamine) release from the ventral tegmental area to the nucleus accumbens; this, in part, determines the addictive liability of a substance. © 1996 - 2011 UBM Medica LLC,

Keyword: Drug Abuse
Link ID: 15261 - Posted: 04.25.2011

By JOHN ELIGON Drunken recollections, especially in rape trials, rarely play well to jurors. In a society that can be quick to turn a skeptical eye toward women who say they were raped — she was scantily dressed, she’s promiscuous, she’s just angry at him — prosecutors of sex crimes say one of their biggest obstacles in the courtroom is alcohol. A rape trial in Manhattan is the latest example. The accuser, who completed her testimony Monday, admitted that she was so drunk on the night in question that she could not remember most of what happened, even the cab ride home. Yet she provided a vivid description of the moment she said she was raped by the police officer who escorted her up to her apartment. Can someone be that drunk, yet remember specific details of an event? According to scientists, it’s possible. But it is also possible that any memory of a drunken episode is colored by suggestion or outside information. When drunk, people sometimes pass out; they become unconscious. Or they could black out — a condition in which they’re conscious but not storing memories. Blackouts tend to start at blood alcohol levels of at least 0.15 percent, about twice the legal limit for driving, especially when a person hits that level quickly. When alcohol floods the hippocampus — a brain region that records our lives as they unfold — neurons stop talking to each other and capturing memories, said Aaron White, a researcher with the National Institute on Alcohol Abuse and Alcoholism. When the hippocampus is off, no matter how hard one tries, a memory will not be recalled because it will not have been recorded in the first place, Dr. White said. © 2011 The New York Times Company

Keyword: Learning & Memory; Drug Abuse
Link ID: 15260 - Posted: 04.25.2011