By R. Douglas Fields Human beings are utterly dependent on a complex social structure for their survival. Since all behavior is controlled by the brain, human beings may have evolved specialized neural circuits that are responsible for compliance with society’s rules. A new study has identified such a region in the human brain, and researchers can increase or decrease a person’s good behavior by electrodes on the scalp that stimulate or inhibit this brain circuit. Individuals must adhere to rules of society, which are ultimately enforced by punishments ranging from peer criticism to severe legal sanctions. “Our findings suggest a neural mechanism that is specialized for social norm compliance,” says Christian Ruff, one of the researchers in this new study published in the October 4, 2013 edition of the journal Science. In addition to illuminating the neurobiological basis for the evolution of social structure in humans, this new finding suggests new therapeutic treatments for people who have problems complying with normal social behavior. “That this mechanism can be upregulated by brain stimulation indeed suggests that targeted influences on these neural processes (by brain stimulation or pharmacology) may help to ameliorate problems with social norm compliance in medical and forensic contexts,” he says. It was already known from fMRI studies that neural activity increased in a specific part of the human cerebral cortex when participants comply with social norms. This region is located in the prefrontal region of the right cerebral hemisphere, called the right lateral prefrontal cortex (rLPFC). However, a correlation between brain activity and behavior does not prove that this neural circuit causes people to comply with social norms. Such proof would require manipulating electrical activity in this brain region to see if people altered their behavior in terms of complying with social expectations. © 2013 Scientific American

Keyword: Emotions
Link ID: 18743 - Posted: 10.05.2013

By PAM BELLUCK Say you are getting ready for a blind date or a job interview. What should you do? Besides shower and shave, of course, it turns out you should read — but not just anything. Something by Chekhov or Alice Munro will help you navigate new social territory better than a potboiler by Danielle Steel. That is the conclusion of a study published Thursday in the journal Science. It found that after reading literary fiction, as opposed to popular fiction or serious nonfiction, people performed better on tests measuring empathy, social perception and emotional intelligence — skills that come in especially handy when you are trying to read someone’s body language or gauge what they might be thinking. The researchers say the reason is that literary fiction often leaves more to the imagination, encouraging readers to make inferences about characters and be sensitive to emotional nuance and complexity. “This is why I love science,” Louise Erdrich, whose novel “The Round House” was used in one of the experiments, wrote in an e-mail. The researchers, she said, “found a way to prove true the intangible benefits of literary fiction.” “Thank God the research didn’t find that novels increased tooth decay or blocked up your arteries,” she added. The researchers, social psychologists at the New School for Social Research in New York City, recruited their subjects through that über-purveyor of reading material, Amazon.com. To find a broader pool of participants than the usual college students, they used Amazon’s Mechanical Turk service, where people sign up to earn money for completing small jobs. Copyright 2013 The New York Times Company

Keyword: Emotions
Link ID: 18742 - Posted: 10.05.2013

by Colin Barras SHAKEN, scorched and boiled in its own juices, this 4000-year-old human brain has been through a lot. It may look like nothing more than a bit of burnt log, but it is one of the oldest brains ever found. Its discovery, and the story now being pieced together of its owner's last hours, offers the tantalising prospect that archaeological remains could harbour more ancient brain specimens than thought. If that's the case, it potentially opens the way to studying the health of the brain in prehistoric times. Brain tissue is rich in enzymes that cause cells to break down rapidly after death, but this process can be halted if conditions are right. For instance, brain tissue has been found in the perfectly preserved body of an Inca child sacrificed 500 years ago. In this case, death occurred at the top of an Andean mountain where the body swiftly froze, preserving the brain. However, Seyitömer Höyük – the Bronze Age settlement in western Turkey where this brain was found – is not in the mountains. So how did brain tissue survive in four skeletons dug up there between 2006 and 2011? Meriç Altinoz at Haliç University in Istanbul, Turkey, who together with colleagues has been analysing the find, says the clues are in the ground. The skeletons were found burnt in a layer of sediment that also contained charred wooden objects. Given that the region is tectonically active, Altinoz speculates that an earthquake flattened the settlement and buried the people before fire spread through the rubble. © Copyright Reed Business Information Ltd.

Keyword: Miscellaneous
Link ID: 18741 - Posted: 10.05.2013

Figuring out the next 99,999,999,900 neurons “We have a hundred billion neurons in each human brain,” said Nicholas Spitzer, a neurobiologist and co-director of the Kavli Institute for Brain and Mind at the University of California-San Diego (which is partnering with The Atlantic on this event). “Right now, the best we can do is to record the electrical activity of maybe a few hundred of those neurons. Gee, that’s not very impressive.” Spitzer and his team are trying to figure out what’s going on in the rest of those neurons, or brain cells – specifically, what "jobs" they have in the body. But first, a bit of Neuroscience 101: “As your readers may know, the nerve cells or neurons in the brain communicate with each other through the release of chemicals, called neurotransmitters,” Spitzer said. “This allows a motor neuron that makes a muscle contract signal to the muscle to say, ‘time to contract.’ It seems like kind of a clumsy way to organize a signaling system.” But sometimes, those neurons change "jobs" – a motor neuron might start signaling another function in the body, for example. "These issues have their origins in the Greek and Roman and Chinese philosophers." “We thought for a long time that the wiring of the brain was a little bit like the wiring of some sort of electronic device in that the connection of the wires in the ‘device,’ the brain, are fairly fixed. What we’re finding is that the wires can remain in place, but the function of the circuit and the connection of the wires can change,” Spitzer said. “This is something of a heresy.” © 2013 by The Atlantic Monthly Group

Keyword: Development of the Brain; Consciousness
Link ID: 18740 - Posted: 10.03.2013

Intelligence tests were first devised in the early twentieth century as a way to identify children who needed extra help in school. It was only later that the growing eugenics movement began to promote use of the tests to weed out the less intelligent and eliminate them from society, sparking a debate over the appropriateness of the study of intelligence that carries on to this day. But it was not the research that was problematic: it was the intended use of the results. As the News Feature on page 26 details, this history is never far from the minds of scientists who work in the most fraught areas of behavioural genetics. Although the ability to investigate the genetic factors that underlie the heritability of traits such as intelligence, violent behaviour, race and sexual orientation is new, arguments and attitudes about the significance of these traits are not. Scientists have a responsibility to do what they can to prevent abuses of their work, including the way it is communicated. Here are some pointers. First: be patient. Do not speculate about the possibility of finding certain results, or about the implications of those results, before your data have even been analysed. The BGI Cognitive Genomics group in Shenzhen, China, is studying thousands of people to find genes that underlie intelligence, but group members sparked a furore by predicting that studies such as theirs could one day let parents select embryos with genetic predispositions to high intelligence. Many other geneticists are sceptical that the project will even find genes linked to this trait. © 2013 Nature Publishing Group

Keyword: Genes & Behavior; Intelligence
Link ID: 18739 - Posted: 10.03.2013

Sarah C. P. Williams A person might be caught off-guard without an umbrella in a sudden downpour, but rain doesn’t catch insects by surprise. Moths, beetles, and aphids predict storms by sensing changes in air pressure and then alter their behavior, researchers have discovered. In particular, the new study finds that insects change their mating behaviors when the air pressure drops, which often precedes rain, or when the air pressure rises, which can signal strong winds. “People have observed before that birds, bats, and even fish respond to changes in [air] pressure,” says entomologist Maria Fernanda Peñaflor of the University of São Paulo in Brazil, a co-author of the new study. “This is the first time such behavior has been studied in insects.” Peñaflor and her colleagues knew that insect behavior was mediated by temperature, wind, and rainfall and wondered whether air pressure played a role as well. They first correlated air pressure data from a local meteorology station with the behavior of male cucurbit beetles (Diabrotica speciosa), green and yellow beetles about 6 millimeters long that feed on cucurbit vegetables, such as cucumbers, pumpkins, and squashes, in South America. They discovered that on days when the pressure was falling—indicating impending rain—the male beetles were less likely to walk in the direction of female pheromones, which they normally follow to pursue mates. To find out more, Peñaflor’s group collaborated with researchers at the University of Western Ontario in Canada who had a controlled pressure chamber in which they could perform experiments. © 2013 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 18738 - Posted: 10.03.2013

by Colin Barras It's like pulling a rabbit out of a hat. Researchers have reached inside the brain of a rat and pulled out neural stem cells – without harming the animal. Since the technique uses nanoparticles already approved for use in humans, it is hoped that it could be used to extract neural stem cells (NSCs) from people to treat conditions like Parkinson's, Huntington's and multiple sclerosis. Extracting NSCs from the person who needs them would avoid immune rejection – but they are difficult to remove safely. So Edman Tsang at the University of Oxford and his colleagues have developed a technique to safely fish out NSCs that originate in cavities in the brain called ventricles. Tsang's team coated magnetic nanoparticles with antibodies that bond tightly to a protein found on the surface of NSCs. They then injected the nanoparticles into the lateral ventricles of rats' brains. Six hours later, after the nanoparticles had bonded to the NSCs, the researchers used a magnetic field around the rats' heads to pull the stem cells together. They could then be sucked out of the brain with a syringe. After freeing the stem cells from the nanoparticles, the team found they could grow them in a dish, suggesting they were undamaged by the process. The rats, meanwhile, were back on their feet within hours of the surgery, showing no ill effects. © Copyright Reed Business Information Ltd.

Keyword: Stem Cells; Regeneration
Link ID: 18737 - Posted: 10.03.2013

By Lenny Bernstein, Joanna Leigh describes her life in black and white, before and after. Before the Boston Marathon bombing, she says, she had “just embarked on a really beautiful future” with a new doctoral degree in international development and a career as a consultant. Today, she says, she can’t work or drive and often gets lost, sometimes on her own block. Her vision is blurry, her hearing is diminished and her ears ring constantly. She struggles to cook dinner, do her laundry, fill out a form. Mostly, she sleeps. The cause of her difficulties, according to the physician who examined her, was a traumatic brain injury on April 15. But because Leigh, 39, walked home that day after she was knocked unconscious by the second bomb and never went to a hospital, she received just $8,000 from the One Fund charity for survivors. She said her medical and other expenses have reached $70,000. She is applying for disability payments and food stamps. One Fund payouts to everyone except 16 amputees and the families of the four people who were killed were based on the number of nights spent in the hospital. A single night was worth $125,000; 32 nights qualified victims for $948,000. The 143 people who were treated as outpatients received $8,000 each. In coming days, Leigh and four other attack survivors will petition the One Fund to develop a new plan for distributing the millions of dollars in donations the charity has received since the first payout. They are seeking a formula that takes into account injuries that were slow to reveal themselves. © 1996-2013 The Washington Post

Keyword: Brain Injury/Concussion
Link ID: 18736 - Posted: 10.03.2013

By NICHOLAS BAKALAR Depression may be an independent risk factor for Parkinson’s disease, a new study has found. In a retrospective analysis, researchers followed 4,634 patients with depression and 18,544 matched controls for 10 years. To rule out the possibility that depression is an early symptom of Parkinson’s disease, their analysis excluded patients who received a diagnosis of depression within five years of their Parkinson’s diagnosis. The average age of people with depression was 41, while it was 64 for those with both depression and Parkinson’s. The study, published online in Neurology, found that 66 patients with depression, or 1.42 percent, developed Parkinson’s disease, compared with 97, or 0.52 percent, among those who were not depressed. After controlling for age, sex, diabetes, hypertension and other factors, the researchers found clinical depression was associated with more than three times the risk for Parkinson’s disease. “Our paper does not convey the message that all depression leads to Parkinson’s disease,” said the senior author, Dr. Albert C. Yang, a professor of psychiatry at the National Yang-Ming University in Taiwan. “But particularly the depressed elderly and those with difficult-to-treat depression should be alert to the possibility of neurological disease and Parkinson’s.” Copyright 2013 The New York Times Company

Keyword: Depression; Parkinsons
Link ID: 18735 - Posted: 10.03.2013

By Travis Riddle Humans like being around other humans. We are extraordinarily social animals. In fact, we are so social, that simply interacting with other people has been shown to be use similar brain areas as those involved with the processing of very basic rewards such as food, suggesting that interacting with people tends to make us feel good. However, it doesn’t take much reflection to notice that the way people interact with each other has radically changed in recent years. Much of our contact happens not face-to-face, but rather while staring at screen-based digital representations of each other, with Facebook being the most prominent example. This raises a very fundamental question – how does online interaction with other people differ from interacting with people in person? One possible way these two interaction styles might differ is through how rewarding we find them to be. Does interacting with Facebook make us feel good as does interacting with people in real life? A recent paper suggests that the answer is “probably not.” In fact, the data from this paper suggest that the more we interact with Facebook, the worse we tend to feel. Researchers recruited participants from around a college campus. The participants initially completed a set of questionnaires, including one measuring their overall satisfaction with life. Following this, participants were sent text messages 5 times a day for two weeks. For each text, participants were asked to respond to several questions, including how good they felt at that moment, as well as how much they had used Facebook, and how much they had experienced direct interaction with others, since the last text. At the end of the two weeks, participants completed a second round of questionnaires. Here, the researchers once again measured participants’ overall satisfaction with life. © 2013 Scientific American

Keyword: Depression; Emotions
Link ID: 18734 - Posted: 10.02.2013

By DENISE GRADY Hormone therapy for menopause is one of the most divisive subjects in medicine, hailed by some as a boon to women’s comfort and well-being, vilified by others as a threat to health. A new analysis finds truth somewhere in the middle, reaffirming previous warnings that the drugs have more risks than benefits for most women — but also stating that the harms are low early in menopause and that hormones are “appropriate for symptom management in some women.” Dr. JoAnn E. Manson, the first author of the analysis and a professor of medicine at Harvard’s medical school, said in an interview that the findings “should not be used as a basis for denying women treatment if they’re in early menopause and have significant distressing symptoms.” The new report, published on Tuesday in The Journal of the American Medical Association, is based on long-term data from the Women’s Health Initiative, a large, federally funded study that turned medical thinking on its head a decade ago by uncovering the risks of hormones. The new report is the first to include extended follow-up data from the original health initiative study, an additional six to eight years’ worth of information on about 80 percent of the original participants. They took a combination of estrogen and progesterone, estrogen alone or placebos for several years. For combined hormones, for every 10,000 women taking the drugs, the new analysis found that there were six additional instances of heart problems, nine more strokes, nine more blood clots in the lungs and nine more cases of breast cancer. On the benefit side, there were six fewer cases of colorectal cancer, one fewer case of uterine cancer, six fewer hip fractures and one fewer death. Most of the effects wore off once the drugs were stopped, but the risk of breast cancer remained slightly elevated. © 2013 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 18733 - Posted: 10.02.2013

By Shelly Fan Disclaimer: First things first. Please note that I am in no way endorsing nutritional ketosis as a supplement to, or a replacement for medication. As you’ll see below, data exploring the potential neuroprotective effects of ketosis are still scarce, and we don’t yet know the side effects of a long-term ketogenic diet. This post talks about the SCIENCE behind ketosis, and is not meant in any way as medical advice. The ketogenic diet is a nutritionist’s nightmare. High in saturated fat and VERY low in carbohydrates, “keto” is adopted by a growing population to paradoxically promote weight loss and mental well-being. Drinking coffee with butter? Eating a block of cream cheese? Little to no fruit? To the uninitiated, keto defies all common sense, inviting skeptics to wave it off as an unnatural “bacon-and-steak” fad diet. Yet versions of the ketogenic diet have been used to successfully treat drug-resistant epilepsy in children since the 1920s – potentially even back in the biblical ages. Emerging evidence from animal models and clinical trials suggest keto may be therapeutically used in many other neurological disorders, including head ache, neurodegenerative diseases, sleep disorders, bipolar disorder, autism and brain cancer. With no apparent side effects. Sound too good to be true? I feel ya! Where are these neuroprotective effects coming from? What’s going on in the brain on a ketogenic diet? In essence, a ketogenic diet mimics starvation, allowing the body to go into a metabolic state called ketosis (key-tow-sis). © 2013 Scientific American

Keyword: Obesity
Link ID: 18732 - Posted: 10.02.2013

by Linda Geddes They say the early bird catches the worm, but night owls may be missing far more than just a tasty snack. Researchers have discovered the first physical evidence of structural brain differences that distinguish early risers from people who like to stay up late. The differences might help to explain why night owls seem to be at greater risk of depression. Around 10 per cent of people qualify as morning people or larks, and a further 20 per cent are night owls – with the rest of us falling somewhere in between. Your lark or night owl status is called your chronotype. Previous studies have suggested that night owls experience worse sleep, more tiredness during the day and consume greater amounts of tobacco and alcohol. This has prompted some to suggest that they are suffering from a form of chronic jet lag. To investigate further, Jessica Rosenberg at RWTH Aachen University in Germany and colleagues used diffusion tensor imaging to scan the brains of 16 larks, 23 night owls and 20 intermediate chronotypes. They found a reduction in the integrity of night owls' white matter – brain tissue largely comprised of fatty insulating material that speeds up the transmission of nerve signals – in areas associated with depression. "We think this could be caused by the fact that late chronotypes suffer from this permanent jet lag," says Rosenberg, although she cautions that further studies are needed to confirm cause and effect. © Copyright Reed Business Information Ltd.

Keyword: Biological Rhythms; Depression
Link ID: 18731 - Posted: 10.01.2013

By Julianne Wyrick Some people are drawn to the thick smell of bacon, sizzling and crackling in the skillet on a Saturday morning. For others, it’s the aroma of freshly baked cookies on a Friday night or the smell of McDonald’s fries creeping in through the car window. At this time of year, I find the scent of freshly baked pumpkin muffins irresistible. Of course, I’d like to think I’m not a slave to my nose, at least not when I’m nice and full from dinner. If I were a fruit fly, my outlook might not be so good. Already-fed fruit fly larvae exposed to certain food-related odors ate more food than larvae that didn’t experience the smells, according to research published by scientists at the University of Georgia last spring. “They’re not hungry, but they will get an extra kick in terms of appetite, so they will eat, for example, 30 percent extra,” said Ping Shen, lead author on the study. The scents, which included the sweet odor of bananas or the sharper smell of balsamic vinegar, served as “cues” or triggers that the flies associated with food. The triggers motivated the fly larvae to eat, even when they’d already had dinner. That doesn’t bode so well for flies trying to watch their weight. For the fly to feel this urge to eat, the smell has to be transported from sensory receptors in the nose to the part of the brain that regulates appetite—the brain’s “feeding center”—via a series of neurons. Part of this signal transfer involves dopamine, a neurotransmitter associated with behavior motivated by a cue or hint of something to come, like smells associated with food. © 2013 Scientific American

Keyword: Obesity; Chemical Senses (Smell & Taste)
Link ID: 18730 - Posted: 10.01.2013

By NICHOLAS BAKALAR Black and Hispanic children who go to an emergency room with stomach pain are less likely than white children to receive pain medication, a new study reports, and more likely to spend long hours in the emergency room. The analysis, published in the October issue of Pediatrics, examined the records of 2,298 emergency room visits by people under 21, a nationally representative sample from a large survey conducted by the Centers for Disease Control and Prevention. About 53 percent were white, 24 percent non-Hispanic black, 21 percent Hispanic, and the rest from other ethnic or racial groups. Over all, 27.1 percent of white children with severe pain received analgesics, but only 15.8 percent of blacks, 18.9 percent of Hispanics and 7.1 percent of children of other races did. Black children were about 68 percent more likely than white children to spend longer than six hours in the emergency room, although there were no statistically significant differences among races in results for any diagnostic test. “This data set will not answer the question of why,” said the lead author, Dr. Tiffani J. Johnson, an instructor at the University of Pennsylvania School of Medicine. “It could be that white parents are more likely to ask for pain meds, or that minority patients are likely to get care in E.R.’s that have longer wait times. And it could be racial bias.” Copyright 2013 The New York Times Company

Keyword: Pain & Touch; Emotions
Link ID: 18729 - Posted: 10.01.2013

By Kendall Powell, Although my grandmother received a diagnosis of Alzheimer’s disease in her 80s, my family was never sure that’s what she had. She certainly suffered from dementia: She was able to recall childhood memories but couldn’t remember what she had had for lunch. But dementia and Alzheimer’s are not synonymous. Back then, the only way to look for the telltale Alzheimer’s plaques — deposits of the protein fragment beta amyloid that accumulate in the spaces between nerve cells — was through an autopsy, which we didn’t do. Over the past 15 years, researchers have developed a greater understanding of how the disease works. We now have more accurate ways of diagnosing Alzheimer’s and are moving closer to developing drugs to directly attack the disease. Much of this work is still in the early stages, but experts are growing more hopeful about dealing with the debilitating disease, which currently has no cure. Now, for example, we no longer have to rely on autopsies to confirm the existence of Alzheimer’s plaques. In a major advance last year, the Food and Drug Administration approved a method that uses a radioactive dye, known commercially as Amyvid, to light up amyloid plaques in a PET scan. The FDA approved Amyvid to rule out Alzheimer’s when the scan is negative and to confirm the presence of plaques when positive, but that does not necessarily indicate the disease is present. However, some doctors are using the scans to confirm the disease, which experts say is misdiagnosed up to a quarter of the time. Paul Aisen, director of the Alzheimer’s Disease Cooperative Study at University of California at San Diego, calls Amyvid an “enormous advance” because a positive scan, combined with his clinical diagnosis, means he can tell patients and their families the disease is “present, not probable.” © 1996-2013 The Washington Post

Keyword: Alzheimers
Link ID: 18728 - Posted: 10.01.2013

Mid-life stress may increase a woman's risk of developing dementia, according to researchers. In a study of 800 Swedish women, those who had to cope with events such as divorce or bereavement were more likely to get Alzheimer's decades later. The more stressful events there were, the higher the dementia risk became, BMJ Open reports. The study authors say stress hormones may be to blame, triggering harmful alterations in the brain. Stress hormones can cause a number of changes in the body and affect things such as blood pressure and blood sugar control. And they can remain at high levels many years after experiencing a traumatic event, Dr Lena Johansson and colleagues explain. But they say more work is needed to confirm their findings and ascertain whether the same stress and dementia link might also occur in men. In the study, the women underwent a battery of tests and examinations when they were in either their late 30s, mid-40s or 50s, and then again at regular intervals over the next four decades. At the start of the study, one in four women said they had experienced at least one stressful event, such as widowhood or unemployment. BBC © 2013

Keyword: Stress; Alzheimers
Link ID: 18727 - Posted: 10.01.2013

By Larry Greenemeier The leaves of the herb kratom (Mitragyna speciosa), a native of Southeast Asia in the coffee family, are used to relieve pain and improve mood as an opiate substitute and stimulant. The herb is also combined with cough syrup to make a popular beverage in Thailand called “4x100.” Because of its psychoactive properties, however, kratom is illegal in Thailand, Australia, Myanmar (Burma) and Malaysia. The U.S. Drug Enforcement Administration lists kratom as a “drug of concern” because of its abuse potential, stating it has no legitimate medical use. The state of Indiana has banned kratom consumption outright. Now, looking to control its population’s growing dependence on methamphetamines, Thailand is attempting to legalize kratom, which it had originally banned 70 years ago. At the same time, researchers are studying kratom’s ability to help wean addicts from much stronger drugs, such as heroin and cocaine. Studies show that a compound found in the plant could even serve as the basis for an alternative to methadone in treating addictions to opioids. The moves are just the latest step in kratom’s strange journey from home-brewed stimulant to illegal painkiller to, possibly, a withdrawal-free treatment for opioid abuse. With kratom’s legal status under review in Thailand and U.S. researchers delving into the substance’s potential to help drug addicts, Scientific American spoke with Edward Boyer, a professor of emergency medicine and director of medical toxicology at the University of Massachusetts Medical School. Boyer has worked with Chris McCurdy, a University of Mississippi professor of medicinal chemistry and pharmacology, and others for the past several years to better understand whether kratom use should be stigmatized or celebrated. © 2013 Scientific American

Keyword: Drug Abuse
Link ID: 18726 - Posted: 10.01.2013

Erika Check Hayden The power of thought alone is not enough to move inanimate objects — unless the object is a robotic leg wired to your brain, that is. A 32-year-old man whose knee and lower leg were amputated in 2009 after a motorcycle accident is apparently the first person with a missing lower limb to control a robotic leg with his mind. A team led by biomedical engineer Levi Hargrove at the Rehabilitation Institute of Chicago in Illinois reported the breakthrough last week in the New England Journal of Medicine1, including a video that shows the man using the bionic leg to walk up stairs and down a ramp, and to kick a football. The major advance is that the man does not have to use a remote-control switch or exaggerated muscle movements to tell the robotic leg to switch between types of movements, and he does not have to reposition the leg with his hands when seated, Hargrove says. “To our knowledge, this is the first time that neural signals have been used to control both a motorized knee and ankle prosthesis,” he says. Scientists had previously shown that paralysed people could move robotic arms using their thoughts and that able-bodied people can walk using robotic legs controlled by their brains (see, for example, go.nature.com/dgtykw). The latest work goes a step further by using muscle signals to amplify messages sent by the brain when the person intends to move. © 2013 Nature Publishing Group

Keyword: Robotics
Link ID: 18725 - Posted: 10.01.2013

Selectively bred strains of laboratory rats that either prefer or avoid alcohol have been a mainstay of alcohol research for decades. So-called alcohol-preferring rats voluntarily consume much greater amounts of alcohol than do non-preferring rats. Scientists at the National Institutes of Health now report that a specific gene plays an important role in the alcohol-consuming tendencies of both types of rats. “This study advances our understanding of the genetics and neurobiology of alcohol consumption in an important animal model of human alcoholism,” says Kenneth R. Warren, Ph.D., acting director of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of NIH. As reported online in the Proceedings of the National Academy of Sciences, a diverse team of scientists, led by David Goldman, M.D., chief of NIAAA’s Laboratory of Neurogenetics, used exome sequencing, an approach that comprehensively analyzes the DNA that encodes proteins. They found a severely dysfunctional form of the gene for a brain signaling molecule called metabotropic glutamate receptor 2 (Grm2), known as a stop codon, in alcohol-preferring rats but not in non-preferring rats. The researchers then demonstrated that drugs and genetic changes that block Grm2 increased alcohol consumption in normal rats and mice. “We’ve long known that genes play an important role in alcoholism,” says Dr. Goldman. “However, the genes and genetic variants that cause alcoholism have remained largely unknown. This first discovery of a gene accounting for alcohol preference in a mammalian model illustrates that genomic analysis of a model organism is a powerful approach for a complex disease such as alcoholism.”

Keyword: Drug Abuse; Genes & Behavior
Link ID: 18724 - Posted: 10.01.2013