Virginia Gewin Nicotine causes changes in gene regulation that enhance the brain's subsequent response to cocaine. The finding, in mice, provides the first clear evidence for a molecular mechanism supporting the idea of 'gateway drugs'. Epidemiologist Denise Kandel at Columbia University, New York, reported back in 1975 that drug-using adolescents had tended to start with cigarettes, which contain the addictive substance nicotine, and alcohol before progressing to more illicit substances such as cocaine1. The idea that smoking and alcohol act as a gateway, making teenagers more likely to experiment with other drugs, has proved controversial ever since. Now Kandel has collaborated with her husband of 56 years, neurobiologist Eric Kandel, and other colleagues at Columbia, to probe the molecular biology underlying the gateway effect. In a study published today in Science Translational Medicine2, the team shows that, in mice at least, nicotine causes epigenetic changes — long-lasting changes in the control of gene expression — that subsequently boost the response to cocaine. Neurobiologists Eric Nestler and Alfred Robison of the Mount Sinai School of Medicine in New York suggested in a review published earlier this month that such gene priming is likely to be at work in drug addiction3. But their prediction was based on limited existing evidence. "This paper is exciting because it is one of the first well-defined characterizations of gene priming by a drug," says Robison. © 2011 Nature Publishing Group,

Keyword: Drug Abuse
Link ID: 15975 - Posted: 11.03.2011

by Andy Coghlan Not all brain regions are created equal – instead, a "rich club" of 12 well-connected hubs orchestrates everything that goes on between your ears. This elite cabal could be what gives us consciousness, and might be involved in disorders such as schizophrenia and Alzheimer's disease. As part of an ongoing effort to map the human "connectome" – the full network of connections in the brain – Martijn van den Heuvel of the University Medical Center in Utrecht, the Netherlands, and Olaf Sporns of Indiana University Bloomington scanned the brains of 21 people as they rested for 30 minutes. The researchers used a technique called diffusion tensor imaging to track the movements of water through 82 separate areas of the brain and their interconnecting neurons. They found 12 areas of the brain had significantly more connections than all the others, both to other regions and among themselves. "These 12 regions have twice the connections of other brain regions, and they're more strongly connected to each other than to other regions," says Van den Heuvel. "If we wanted to look for consciousness in the brain, I would bet on it turning out to be this rich club," he adds. The elite group consists of six pairs of identical regions, with one of each pair in each hemisphere of the brain. Each member is known to accept only preprocessed, high-order information, rather than raw incoming sensory data. © Copyright Reed Business Information Ltd.

Keyword: Attention; Drug Abuse
Link ID: 15974 - Posted: 11.03.2011

by Peter Aldhous An announcement for children being treated for attention deficit hyperactivity disorder: the drugs used do not seem to increase the risk of stroke, heart attack or sudden death from heart failure. Fears about cardiovascular side effects surfaced in 2006, when the US Food and Drug Administration was looking into 25 reports of sudden deaths among people taking the stimulants, 19 of them children. A team led by William Cooper of Vanderbilt University in Nashville, Tennessee, has now studied more than 1.2 million children and young adults, following each for more than two years on average. They recorded just 81 serious cardiovascular events, and these were no more likely to have occurred in the minority taking stimulant drugs. Long-term question However, questions about the drugs' safety will remain. Given that they can increase heart rate and blood pressure. Almut Winterstein at the University of Florida in Gainesville is concerned about the effects of long-term use. She has found that more than 15 per cent of children in Florida who are prescribed stimulants carry on taking them for at least five years. In addition to 2.7 million or more American children, it is thought that at least 1.5 million adults in the US are currently taking stimulants for ADHD. Older adults may be at some risk, given that cardiovascular disease is more common with advancing age. © Copyright Reed Business Information Ltd.

Keyword: ADHD
Link ID: 15973 - Posted: 11.03.2011

By KATE MURPHY Overuse of antibiotics has led to the creation of drug-resistant bacteria — so-called superbugs, like methicillin-resistant staphylococcus aureus. But now some researchers are exploring an equally unsettling possibility: Antibiotic abuse may also be contributing to the increasing incidence of obesity, as well as allergies, inflammatory bowel disease, asthma and gastroesophageal reflux. Among those sounding the alarm is Dr. Martin Blaser, a professor of microbiology at New York University Langone Medical Center. In a commentary published in August in the journal Nature, he asserted that antibiotics are permanently altering microbial flora of the human body, also known as the microbiome or microbiota, with serious health consequences. The human gut in particular is home to billions of bacteria, but little is known about this hidden ecosystem. Take Helicobacter pylori, a bacterium associated with an increased risk of ulcers and gastric cancer. Many doctors are quick to prescribe antibiotics to kill it even when the patient has no symptoms. But in 1998, in a paper published in the British Medical Journal, Dr. Blaser was more circumspect, arguing that H. pylori might not be such a bad actor after all. “We’re talking about a bug that’s been in the human gut for at least 58,000 years,” Dr. Blaser said in an interview. “There’s probably a reason for that.” His lab has since produced a stream of findings supporting his suspicion. Dr. Blaser and his colleagues discovered, for instance, that the stomach behaves differently after a course of antibiotics eradicates resident H. pylori. © 2011 The New York Times Company

Keyword: Obesity
Link ID: 15972 - Posted: 11.03.2011

By BENEDICT CAREY ST. HELENA, Calif. — The scientists exchanged one last look and held their breath. Everything was ready. The electrode was in place, threaded between the two hemispheres of a living cat’s brain; the instruments were tuned to pick up the chatter passing from one half to the other. The only thing left was to listen for that electronic whisper, the brain’s own internal code. The amplifier hissed — the three scientists expectantly leaning closer — and out it came, loud and clear. “We all live in a yellow submarine, yellow submarine, yellow submarine ....” “The Beatles’ song! We somehow picked up the frequency of a radio station,” recalled Michael S. Gazzaniga, chuckling at the 45-year-old memory. “The brain’s secret code. Yeah, right!” Dr. Gazzaniga, 71, now a professor of psychology at the University of California, Santa Barbara, is best known for a dazzling series of studies that revealed the brain’s split personality, the division of labor between its left and right hemispheres. But he is perhaps next best known for telling stories, many of them about blown experiments, dumb questions and other blunders during his nearly half-century career at the top of his field. Now, in lectures and a new book, he is spelling out another kind of cautionary tale — a serious one, about the uses of neuroscience in society, particularly in the courtroom. Brain science “will eventually begin to influence how the public views justice and responsibility,” Dr. Gazzaniga said at a recent conference here sponsored by the Edge Foundation. © 2011 The New York Times Company

Keyword: Miscellaneous
Link ID: 15971 - Posted: 11.01.2011

By Jennifer Viegas A 25-year-old chimpanzee named "Panzee" has just demonstrated that speech perception is not a uniquely human trait. Well-educated Panzee understands more than 130 English language words and even recognizes words in sine-wave form, a type of synthetic speech that reduces language to three whistle-like tones. This shows that she isn't just responding to a particular person's voice or emotions, but instead she is processing and perceiving speech as humans do. "The results suggest that the common ancestor of chimpanzees and humans may have had the capability to perceive speech-like sounds before the evolution of speech, and that early humans were taking advantage of this latent ability when speech did eventually emerge," said Lisa Heimbauer who presented a talk today on the chimp at the 162nd Meeting of the Acoustical Society of America in San Diego. Heimbauer, a doctoral candidate and researcher at Georgia State University's Language Research Center, and colleagues Michael Owren and Michael Beran tested Panzee on her ability to understand words communicated via sine-wave speech, which replicates the estimated frequency and amplitude patterns of natural utterances. "Tickle," "M&M," "lemonade," and "sparkler" were just a few of the test words. Even when the words were stripped of the acoustic constituents of natural speech, Panzee knew what they meant, correctly matching them to corresponding photos. The findings refute what is known as the "Speech is Special" theory. © 2011 Discovery Communications, LLC.

Keyword: Language; Evolution
Link ID: 15970 - Posted: 11.01.2011

Keyword: Miscellaneous
Link ID: 15969 - Posted: 11.01.2011

By The Editors As many as 35 million people worldwide have Alzheimer's disease, the most common form of dementia among adults over 60 years of age. That figure could reach 115 million by 2050, concludes the nonprofit Alzheimer's Disease International. In the U.S., about 5 percent of adults 65 to 74 have Alzheimer's, and nearly half of those age 85 and older may have it, according to figures of the Centers of Disease Control and Prevention. The predominant explanation for how Alzheimer's disease develops and ravages the brain are explained at a new site built by TheVisualMD. We present a few examples of the stunning graphics used on the site below. You can read the complete e-book at TheVisualMD landing page here. © 2011 Scientific American,

Keyword: Alzheimers
Link ID: 15968 - Posted: 11.01.2011

By James Gallagher Health reporter, BBC News The idea of making brain cancers glow to help surgeons operate is being tested in the UK. Patients will be given a drug, 5-amino-levulinic acid (5-ALA), which causes a build-up of fluorescent chemicals in the tumour. The theory is that the pink glow will clearly mark the edges of the tumour, making it easier to ensure all of it is removed. More than 60 patients with glioblastoma will take part in the trial. They have cancerous glial cells, which normally hold the brain's nerves cells in place. On average patients survive 15 months after being diagnosed. No room for error In some cancers, such as those of the colon, some of the surrounding tissue can be removed as well as the tumour. Removing a brain tumour needs to be more precise. Dr Colin Watts, who is leading the trial at the University of Cambridge, told the BBC that surgeons "don't want to take too much functional tissue away". BBC © 2011

Keyword: Neurotoxins
Link ID: 15967 - Posted: 11.01.2011

by Helen Fields Happy people don't just enjoy life; they're likely to live longer, too. A new study has found that those in better moods were 35% less likely to die in the next 5 years when taking their life situations into account. The traditional way to measure a person's happiness is to ask them about it. But over the past few decades, psychologist and epidemiologist Andrew Steptoe of University College London (UCL) says, scientists have realized that those measures aren't reliable. It's not clear whether they "assess how they're actually feeling or how they remember feeling," he says. When answering, people are more likely to count their blessings and compare their experience with the lives of others. The English Longitudinal Study of Ageing tried to get more specific. It has followed more than 11,000 people age 50 and older since 2002. In 2004, about 4700 of them collected saliva samples four times in one day and, at those same times, rated how happy, excited, content, worried, anxious, and fearful they felt. The saliva samples are still awaiting analysis for stress hormones, but Steptoe and his UCL colleague Jane Wardle publish findings today on the links between mood and mortality in the Proceedings of the National Academy of Sciences . Of the 924 people who reported the least positive feelings, 7.3%, or 67, died within 5 years. For people with the most positive feelings, the rate fell in half, to 3.6%, or 50 of 1399 people. Of course, it's possible that people who died sooner weren't as chipper because they were deathly ill or because of any number of other factors that affect both mortality and mood. The researchers adjusted for age, sex, demographic factors such as wealth and education, signs of depression, health (including whether they'd been diagnosed with major diseases), and health behaviors such as smoking and physical activity. Even with those adjustments, the risk of dying in the next 5 years was still 35% lower for the happiest people. © 2010 American Association for the Advancement of Science

Keyword: Emotions
Link ID: 15966 - Posted: 11.01.2011

By Danielle Perszyk Are humans the only species with enough smarts to craft a language? Most of us believe that we are. Although many animals have their own form of communication, none has the depth or versatility heard in human speech. We are able to express almost anything on our mind by uttering a few sounds in a particular order. Human language has a flexibility and complexity that seems to be universally shared across cultures and, in turn, contributes to the variation and richness we find among human cultures. But are the rules of grammar unique to human language? Perhaps not, according to a recent study, which showed that songbirds may also communicate using a sophisticated grammar—a feature absent in even our closest relatives, the nonhuman primates. Kentaro Abe and Dai Watanabe of Kyoto University performed a series of experiments to determine whether Bengalese finches expect the notes of their tunes to follow a certain order. To test this possibility, Abe and Watanabe took advantage of a behavioral response called habituation, where animals zone-out when exposed to the same stimulus over and over again. In each experiment, the birds were presented with the same songs until they became familiarized with the tune. The researchers then created novel songs by shuffling the notes around. But not every new song caught the birds’ attention; rather, the finches increased response calls only to songs with notes arranged in a particular order, suggesting that the birds used common rules when forming the syntax of that song. When the researchers created novel songs with even more complicated artificial grammar—for example, songs that mimicked a specific feature found in human (Japanese) language—the birds still only responded to songs that followed the rules. © 2011 Scientific American

Keyword: Language; Evolution
Link ID: 15965 - Posted: 10.29.2011

Sandrine Ceurstemont, editor, New Scientist TV A ring trapped in a box seems determined to escape in this latest illusion by psychophysiologist Marcel de Heer. To create the brain trick, he created a virtual material with unique properties. The exterior surface is transparent and the interior is lined with a red and yellow pattern. "The material is similar to a one-way mirror," says de Heer. "From one side, you can see through it. From the other side, you see a coloured pattern instead of a mirror." As the box turns, the ring's behaviour starts to get unusual. When viewed from behind, you can see through it. But as it rotates so that it faces you, it sometimes seems to spin in the opposite direction and escape from the box. De Heer isn't exactly sure why we experience the effect, although it's a variation of the hollow mask illusion. Since we are used to seeing convex surfaces like faces, our brain is sometimes tricked by hollow structures and they appear to bulge out. In this case, the curious material seems to confuse our brain in the same way. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 15964 - Posted: 10.29.2011

by Arran Frood The visions induced by an Amazonian brew used by shamans may be as real as anything the eyes actually see, according to brain scans of frequent users of the drug. Draulio de Araujo of the Brain Institute at the Federal University of Rio Grande do Norte in Natal, Brazil, and colleagues recruited 10 frequent users of the brew – called ayahuasca. They asked the volunteers to look at images of people or animals while their brains were scanned using functional MRI, then asked the volunteers to close their eyes and imagine they were still viewing the image. Unsurprisingly, the researchers found that neural activity in the primary visual cortex dropped off when volunteers imagined seeing the image rather than actually viewing it. But when the team then gave the volunteers a dose of ayahuasca and repeated the experiment, they found that the level of activity in the primary visual cortex was virtually indistinguishable when the volunteers were really viewing an image and when they were imagining it. This means visions seen have a real, neurological basis, says de Araujo – they are not made up or imagined. Michael Brammer, head of the brain imaging unit at King's College London, says the study's statistics appear to indicate something relatively robust. However, he says it's difficult to pin down whether the eyes-closed responses on the drug are quantitatively the same as normal, eyes-open neural activity. "Functional MRI is not a one-to-one mapping of cerebral activity. If it were, things would be easier," he says. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Brain imaging
Link ID: 15963 - Posted: 10.29.2011

IF YOU think the art of mind-reading is a conjuring trick, think again. Over the past few years, the ability to connect first monkeys and then men to machines in ways that allow brain signals to tell those machines what to do has improved by leaps and bounds. In the latest demonstration of this, just published in the Public Library of Science, Bin He and his colleagues at the University of Minnesota report that their volunteers can successfully fly a helicopter (admittedly a virtual one, on a computer screen) through a three-dimensional digital sky, merely by thinking about it. Signals from electrodes taped to the scalp of such pilots provide enough information for a computer to work out exactly what the pilot wants to do. That is interesting and useful. Mind-reading of this sort will allow the disabled to lead more normal lives, and the able-bodied to extend their range of possibilities still further. But there is another kind of mind-reading, too: determining, by scanning the brain, what someone is actually thinking about. This sort of mind-reading is less advanced than the machine-controlling type, but it is coming, as three recently published papers make clear. One is an attempt to study dreaming. A second can reconstruct a moving image of what an observer is looking at. And a third can tell what someone is thinking about. First, dreams. To study them, Martin Dresler, of the Max Planck Institute of Psychiatry, in Munich, and his colleagues recruited a group of what are known as lucid dreamers. They report their results in this week’s Current Biology. © The Economist Newspaper Limited 2011

Keyword: Brain imaging; Sleep
Link ID: 15962 - Posted: 10.29.2011

By Laura Sanders Human brains all work pretty much the same and use roughly the same genes in the same way to build and maintain the infrastructure that makes people who they are, two new studies show. And by charting the brain’s genetic activity from before birth to old age, the studies reveal that the brain continually remodels itself in predictable ways throughout life. In addition to uncovering details of how the brain grows and ages, the results may help scientists better understand what goes awry in brain disorders such as schizophrenia and autism. “The complexity is mind-numbing,” says neuroscientist Stephen Ginsberg of the Nathan Kline Institute and New York University Langone Medical Center, who wasn’t involved in the studies. “It puts the brain in rarefied air.” In the studies, published in the Oct. 27 Nature, researchers focused not on DNA — virtually every cell’s raw genetic material is identical — but on when, where and for how long each gene is turned on over the course of a person’s life. To do this, the researchers measured levels of mRNA, a molecule whose appearance marks one of the first steps in executing the orders contained in a gene, in postmortem samples of donated brains that ranged in age from weeks after conception to old age. These different patterns of mRNA levels distinguish the brain from a heart, for instance, and a human from a mouse, too, says Nenad Šestan of Yale University School of Medicine and coauthor of one of the studies. “Essentially, we carry the same genes as mice,” he says. “However, in us, these genes are up to something quite different.” © Society for Science & the Public 2000 - 2011

Keyword: Genes & Behavior
Link ID: 15961 - Posted: 10.29.2011

Despite vast differences in the genetic code across individuals and ethnicities, the human brain shows a "consistent molecular architecture," say researchers supported by the National Institutes of Health. The finding is from a pair of studies that have created databases revealing when and where genes turn on and off in multiple brain regions through development. "Our study shows how 650,000 common genetic variations that make each of us a unique person may influence the ebb and flow of 24,000 genes in the most distinctly human part of our brain as we grow and age," explained Joel Kleinman, M.D., Ph.D., of the National Institute of Mental Health (NIMH) Clinical Brain Disorders Branch. Kleinman and NIMH grantee Nenad Sestan, M.D., Ph.D. of Yale University, New Haven, Conn., led the sister studies in the Oct. 27, 2011 issue of the journal Nature. genetic difference vs. transcriptional distance colored by race comparison. Our brains are all made of the same stuff. Despite individual and ethnic genetic diversity, our prefrontal cortex shows a consistent molecular architecture. For example, overall differences in the genetic code (“genetic distance”) between African -Americans (AA) and caucasians (cauc) showed no effect on their overall difference in expressed transcripts (“transcriptional distance”). The vertical span of color-coded areas is about the same, indicating that our brains all share the same tissue at a molecular level, despite distinct DNA differences on the horizontal axis. Each dot represents a comparison between two individuals. The AA::AA comparisons (blue) generally show more genetic diversity than cauc::cauc comparisons (yellow), because caucasians are descended from a relatively small subset of ancestors who migrated from Africa, while African Americans are descended from a more diverse gene pool among the much larger population that remained in Africa. AA::cauc comparisons (green) differed most across their genomes as a whole, but this had no effect on their transcriptomes as a whole. Source: Joel Kleinman, M.D., Ph.D., NIMH Clinical Brain Disorders Branch

Keyword: Genes & Behavior
Link ID: 15960 - Posted: 10.29.2011

By Dina ElBoghdady, A chemical used widely in plastic bottles, metal cans and other consumer products could be linked to behavioral and emotional problems in toddler girls, according to a government-funded study published online Monday in the journal Pediatrics. After tracking 244 Cincinnati-area mothers and their 3-year-olds, the study concluded that mothers with high levels of bisphenol A (BPA) in their urine were more likely to report that their children were hyperactive, aggressive, anxious, depressed and less in control of their emotions than mothers with low levels of the chemical. While several studies have linked BPA to behavioral problems in children, this report is the first to suggest that a young girl’s emotional well-being is linked to her mother’s exposure during pregnancy rather than the child’s exposure after birth. Girls were more sensitive to the chemical in the womb than boys, maybe because BPA mimics the female hormone estrogen, which is thought to play a role in behavioral development. The results add to a growing body of research that suggests exposure to BPA poses health risks in humans. While the federal government has long maintained that low doses of BPA are safe, the Food and Drug Administration and other federal agencies are taking a closer look and investing in more research about the chemical’s health effects. © 1996-2011 The Washington Post

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 15959 - Posted: 10.29.2011

by Kim Krieger Some sounds are excruciating. Take fingernails squeaking on a chalkboard. The noise makes many people shudder, but researchers never knew exactly why. A new study finds that there are two factors at work: the knowledge of where the sound is coming from and the unfortunate design of our ear canals. Previous research found that the painful parts of unpleasant sounds appear to be in the middle range of audible frequencies. But scientists didn’t nail down exactly which frequencies or explain why the sounds were painful. So musicologists Michael Oehler of the Macromedia University for Media and Communication in Cologne, Germany, and Christoph Reuter of the University of Vienna asked listeners to rank sounds in a listening test. Fingernails raking against a chalkboard and chalk squeaking against slate were the most unpleasant sounds from a family of recordings, which also included sounds such as Styrofoam squeaks and scraping a plate with a fork. The researchers then modified the recordings of fingernails and chalk, removing or attenuating various frequency ranges. They also modified the sounds by selectively extracting either the tonal, musical-pitch parts or the scraping, growling, noiselike parts of the sound. Some listeners were told the true source of the sounds, whereas others were told that the sounds were part of contemporary musical compositions. The same listeners then rated the pleasantness or unpleasantness of the sounds while the researchers measured physical indicators of distress: the listeners’ heart rate, blood pressure, and the electrical conductivity of their skin. As they will report next week at the Acoustical Society of America conference in San Diego, California, Oehler and Reuter found that a listener’s skin conductivity changed significantly when the person heard a sound he or she later reported as unpleasant, showing that disturbing sounds do cause a measurable physical reaction. More surprisingly, they found that the frequencies responsible for making a sound unpleasant were commonly found in human speech, which ranges from 150 to 7000 hertz (Hz). The offending frequencies were in the range of 2000 to 4000 Hz. Removing those made the sounds much easier to listen to. Deleting the tonal parts of the sound entirely also made listeners perceive the sound as more pleasant, whereas removing other frequencies or the noisy, scraping parts of the sound made little difference. © 2010 American Association for the Advancement of Science.

Keyword: Hearing
Link ID: 15958 - Posted: 10.29.2011

by David Eagleman Only a tiny fraction of the brain is dedicated to conscious behavior. The rest works feverishly behind the scenes regulating everything from breathing to mate selection. In fact, neuroscientist David Eagleman of Baylor College of Medicine argues that the unconscious workings of the brain are so crucial to everyday functioning that their influence often trumps conscious thought. To prove it, he explores little-known historical episodes, the latest psychological research, and enduring medical mysteries, revealing the bizarre and often inexplicable mechanisms underlying daily life. Eagleman’s theory is epitomized by the deathbed confession of the 19th-century mathematician James Clerk Maxwell, who developed fundamental equations unifying electricity and magnetism. Maxwell declared that “something within him” had made the discoveries; he actually had no idea how he’d achieved his great insights. It is easy to take credit after an idea strikes you, but in fact, neurons in your brain secretly perform an enormous amount of work before inspiration hits. The brain, Eagleman argues, runs its show incognito. Or, as Pink Floyd put it, “There’s someone in my head, but it’s not me.” There is a looming chasm between what your brain knows and what your mind is capable of accessing. Consider the simple act of changing lanes while driving a car. Try this: Close your eyes, grip an imaginary steering wheel, and go through the motions of a lane change. Imagine that you are driving in the left lane and you would like to move over to the right lane. Before reading on, actually try it. I’ll give you 100 points if you can do it correctly. © 2011, Kalmbach Publishing Co.

Keyword: Attention
Link ID: 15957 - Posted: 10.29.2011

By Wynne Parry Marijuana hurts memory and cognition, and a new rat study indicates this is because it causes once-coordinated brain regions to fall out of sync with each other. The result resembles the effects of schizophrenia, the neuroscientists found. The researchers measured the electrical activity in nerve cells of rats given a drug that mimics the effect of the psychoactive ingredient in marijuana, called tetrahydrocannabinol (THC). The drug had only subtle effects on individual brain regions; however, it disrupted the coordinated activity between regions of the brain. Specifically, they found the drug disrupted the coordinated fluctuations in electrical activity -- called brain waves -- across the hippocampus and prefrontal cortex. The result resembled two instruments within an orchestra playing out of sync. A lack of synchronization between the hippocampus and the prefrontal cortex -- areas of the brain associated with memory and decision-making -- is also associated with schizophrenia. A group of severe brain disorders, schizophrenia causes people to interpret reality abnormally. Its symptoms may include a combination of hallucinations, delusions and disordered thinking and behavior, according to the Mayo Clinic. As a result of the disruption to their brain activity, the rats became unable to make accurate decisions when navigating around a maze. © 2011 CBS Interactive Inc

Keyword: Learning & Memory; Drug Abuse
Link ID: 15956 - Posted: 10.27.2011