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By Katherine Ellison Dr. Mark Bertin is no A.D.H.D. pill-pusher. The Pleasantville, N.Y., developmental pediatrician won’t allow drug marketers in his office, and says he doesn’t always prescribe medication for children diagnosed with attention deficit hyperactivity disorder. Yet Dr. Bertin has recently changed the way he talks about medication, offering parents a powerful argument. Recent research, he says, suggests the pills may “normalize” the child’s brain over time, rewiring neural connections so that a child would feel more focused and in control, long after the last pill was taken. “There might be quite a profound neurological benefit,” he said in an interview. A growing number of doctors who treat the estimated 6.4 million American children diagnosed with A.D.H.D. are hearing that stimulant medications not only help treat the disorder but may actually be good for their patients’ brains. In an interview last spring with Psych Congress Network, http://www.psychcongress.com/video/are-A.D.H.D.-medications-neurotoxic-or-neuroprotective-16223an Internet news site for mental health professionals, Dr. Timothy Wilens, chief of child and adolescent psychiatry at Massachusetts General Hospital, said “we have enough data to say they’re actually neuroprotective.” The pills, he said, help “normalize” the function and structure of brains in children with A.D.H.D., so that, “over years, they turn out to look more like non-A.D.H.D. kids.” Medication is already by far the most common treatment for A.D.H.D., with roughly 4 million American children taking the pills — mostly stimulants, such as amphetamines and methylphenidate. Yet the decision can be anguishing for parents who worry about both short-term and long-term side effects. If the pills can truly produce long-lasting benefits, more parents might be encouraged to start their children on these medications early and continue them for longer. Leading A.D.H.D. experts, however, warn the jury is still out. © 2015 The New York Times Company
The longer a teenager spends using electronic devices such as tablets and smartphones, the worse their sleep will be, a study of nearly 10,000 16- to 19-year-olds suggests. More than two hours of screen time after school was strongly linked to both delayed and shorter sleep. Almost all the teens from Norway said they used the devices shortly before going to bed. Many said they often got less than five hours sleep a night, BMJ Open reports. The teens were asked questions about their sleep routine on weekdays and at weekends, as well as how much screen time they clocked up outside school hours. On average, girls said they spent around five and a half hours a day watching TV or using computers, smartphones or other electronic devices. And boys spent slightly more time in front of a screen - around six and a half hours a day, on average. Playing computer games was more popular among the boys, whereas girls were more likely to spend their time chatting online. teen using a laptop Any type of screen use during the day and in the hour before bedtime appeared to disrupt sleep - making it more difficult for teenagers to nod off. And the more hours they spent on gadgets, the more disturbed their sleep became. When daytime screen use totalled four or more hours, teens had a 49% greater risk of taking longer than an hour to fall asleep. These teens also tended to get less than five hours of sleep per night. Sleep duration went steadily down as gadget use increased. © 2015 BBC
By Lenny Bernstein Parkinson's Disease patients secretly treated with a placebo instead of their regular medication performed better when told they were receiving a more expensive version of the "drug," researchers reported Wednesday in an unprecedented study that involved real patients. The research shows that the well-documented "placebo effect" -- actual symptom relief brought about by a sham treatment or medication -- can be enhanced by adding information about cost, according to the lead author of the study. It is the first time that concept has been demonstrated using people with a real illness, in this case Parkinson's, a progressive neurological disease that has no cure, according to an expert not involved in the study. "The potentially large benefit of placebo, with or without price manipulations, is waiting to be untapped for patients with [Parkinson's Disease], as well as those with other neurologic and medical diseases," the authors wrote in a study published online Wednesday in the journal Neurology. But deceiving actual patients in a research study raised ethical questions about violating the trust involved in a doctor-patient relationship. Most studies in which researchers conceal their true aims or other information from subjects are conducted with healthy volunteers. This one was subjected to a lengthy review before it was allowed to proceed, and, in an editorial that accompanied the article, two other physicians wrote that "the authors do not mention whether there was any possible effect (reduction) on trust in doctors or on willingness to engage in future clinical research."
|By Esther Landhuis One in nine Americans aged 65 and older has Alzheimer's disease, a fatal brain disorder with no cure or effective treatment. Therapy could come in the form of new drugs, but some experts suspect drug trials have failed so far because compounds were tested too late in the disease's progression. By the time people show signs of dementia, their brains have lost neurons. No therapy can revive dead cells, and little can be done to create new ones. So researchers running trials now seek participants who still pass as cognitively normal but are on the verge of decline. These “preclinical” Alzheimer's patients may represent a window of opportunity for therapeutic intervention. How to identify such individuals before they have symptoms presents a challenge, however. Today most Alzheimer's patients are diagnosed after a detailed medical workup and extensive tests that gauge mental function. Other tests, such as spinal fluid analyses and positron-emission tomography (PET) scans, can detect signs of approaching disease and help pinpoint the preclinical window but are cumbersome or expensive. “There's no cheap, fast, noninvasive test that can identify people at risk of Alzheimer's,” says Brad Dolin, chief technology officer of Neurotrack in Palo Alto, Calif.—a company developing a computerized visual screening test for Alzheimer's. Unlike other cognitive batteries, the Neurotrack test requires no language or motor skills. Participants view images on a monitor while a camera tracks their eye movements. The test draws on research by co-founder Stuart Zola of Emory University, who studies learning and memory in monkeys. When presented with a pair of images—one novel, the other familiar—primates fixate longer on the novel one. But if the hippocampus is damaged, as it is in people with Alzheimer's, the subject does not show a clear preference for the novel images. © 2015 Scientific American
By James Gallagher Health editor, Our internal body clock has such a dramatic impact on sporting ability that it could alter the chances of Olympic gold, say researchers. The team at the University of Birmingham showed performance times varied by 26% throughout the day. Early risers reached their athletic peak around lunchtime, while night owls were best in the evening. The researchers say it could even explain why Spanish teams have more success in European football. The body clock controls everything - from alertness to the risk of a heart attack - in a daily rhythm. Some aspects of sporting ability were thought to peak in early afternoon but a study in the journal Current Biology suggests each competitor's sleeping habits have a powerful impact. They took 20 female hockey players and asked them to perform a series of 20m runs in shorter and shorter times. And they did it at six different times of day between 07:00 and 22:00. The results showed a peak performance in late afternoon, but then the scientists looked separately at early-type people, late-type people and those in the middle. This time the gap between the best and worst times was 26%, and a far more complicated picture emerged. Lead researcher Dr Roland Brandstaetter told the BBC News website: "Athletes and coaches would benefit greatly if they knew when optimal or suboptimal performance time was." He said a 1% difference in performance would be the difference between fourth place and a medal in many Olympic events. Body clocks can be adjusted. Jet lag is when you feel rough before adjusting to a new time. "So if you're an early type in a competition in the evening, then you're impaired, so you could adjust sleeping times to the competition," Dr Brandstaetter said. © 2015 BBC.
Keyword: Biological Rhythms
Link ID: 20540 - Posted: 02.02.2015
Alison Abbott German police seized documents in a raid on Tuesday on the Max Planck Institute for Biological Cybernetics in Tübingen, as part of an investigation into alleged violations of animal-protection laws. The investigation was launched last year after a video shot by an animal-rights activist who infiltrated the institute was broadcast on television in September. An independent investigation carried out by the Max Planck Society found no systematic problems, and this month the state government of Baden-Württemberg said that, following its own investigations, it saw no reason to revoke any animal licences. A spokesperson for the Max Planck Society in Munich, who asked not to be named, told Nature that activists were carrying out an unjustified campaign against the institute, where some scientists use monkeys in their research on how the brain works. “There is an agreed consensus within society about how much research can be done with animals and in what conditions,” the spokesperson said, adding that society wants researchers to tackle diseases such as dementia — but that this cannot be done without using animals. “The work is carried out correctly in Tübingen — we have nothing to hide.” Friedrich Mülln, head of the Augsburg-based activist group SOKO Tierschutz — which last year pledged to continue actions against the institute until it stopped its monkey research — says that the Max Planck Society is lying about the animals' treatment, and that the Tübingen institute is a “black mark on an otherwise admirable organization”. He added that his group is working closely with police. © 2015 Nature Publishing Group,
Keyword: Animal Rights
Link ID: 20539 - Posted: 02.02.2015
By ERICA GOODE A study suggests that newborn chicks map numbers spatially, associating low numerical values with space to their left. Credit Rosa Rugani/University of Padova Asked to picture the numbers from one to 10, most people will imagine a straight line with one at the left end and 10 at the right. This “mental number line,” as researchers have termed it, is so pervasive that some scientists have argued that the spatial representation of numbers is hard-wired into the brain, part of a primitive number system that underlies humans’ capacity for higher mathematics. Now a team of Italian researchers has found that newborn chicks, like humans, appear to map numbers spatially, associating smaller amounts with the left side and larger amounts with the right side. The chicks, trained to seek out mealworms behind white plastic panels printed with varying numbers of identical red squares, repeatedly demonstrated a preference for the left when the number of squares was small and for the right when the number was larger. The research, led by Rosa Rugani, a psychologist who at the time was at the University of Padova, will appear in Friday’s issue of the journal Science. Researchers demonstrated that chickens naturally order numbers left to right. When the number five is in the middle, chickens naturally go left for lower numbers and to the right for higher numbers. Publish Date January 29, 2015. In their report, the researchers said the findings supported the idea that the left-right orientation for numbers is innate rather than determined by culture or education — a possibility that was raised by some studies that found that in Arabic-speaking countries where letters and numbers are read right to left, the mental number scale was reversed. But the new research, Dr. Rugani and her colleagues wrote, indicates that orienting numbers in space may represent “a universal cognitive strategy available soon after birth.” Tyler Marghetis, a doctoral candidate in psychology at the University of California, San Diego, who has published research on the spatial association of numbers, called the researcher’s studies “very cool.” © 2015 The New York Times Company
by Clare Wilson Once only possible in an MRI scanner, vibrating pads and electrode caps could soon help locked-in people communicate on a day-to-day basis YOU wake up in hospital unable to move, to speak, to twitch so much as an eyelid. You hear doctors telling your relatives you are in a vegetative state – unaware of everything around you – and you have no way of letting anyone know this is not the case. Years go by, until one day, you're connected to a machine that allows you to communicate through your brain waves. It only allows yes or no answers, but it makes all the difference – now you can tell your carers if you are thirsty, if you'd like to sit up, even which TV programmes you want to watch. In recent years, breakthroughs in mind-reading technology have brought this story close to reality for a handful of people who may have a severe type of locked-in syndrome, previously diagnosed as being in a vegetative state. So far, most work has required a lab and a giant fMRI scanner. Now two teams are developing devices that are portable enough to be taken out to homes, to help people communicate on a day-to-day basis. The technology might also be able to identify people who have been misdiagnosed. People with "classic" locked-in syndrome are fully conscious but completely paralysed apart from eye movements. Adrian Owen of Western University in London, Canada, fears that there is another form of the condition where the paralysis is total. He thinks that a proportion of people diagnosed as being in a vegetative state – in which people are thought to have no mental awareness at all – are actually aware but unable to let anyone know. "The possibility is that we are missing people with some sort of complete locked-in syndrome," he says. © Copyright Reed Business Information Ltd.
By Janice Neumann (Reuters Health) - Moderate-intensity exercise, or even just walking, can improve quality of life for depressed middle-aged women, a large Australian study suggests. Women who averaged 150 minutes of moderate exercise (golf, tennis, aerobics classes, swimming, or line-dancing) or 200 minutes of walking every week had more energy, socialized more, felt better emotionally, and weren't as limited by their depression when researchers followed up after three years. They also had less pain and did better physically, although the psychological benefit was greater. With depression so prevalent, "there is an urgent need" to identify treatments, including non-medical options that people can do themselves, said Kristiann Heesch, who led the study. Heesch, senior lecturer at Queensland University of Technology, and her colleagues point out in a January 13 online article in the American Journal of Preventive Medicine that depression is expected to be the second-leading cause of global disease by 2030 and the leading cause in high-income countries. One in 10 U.S. adults suffers from depression, according to the Centers for Disease Control and Prevention. Women are 70% more likely to be depressed at some point in their lives than men, according to the National Institute of Mental Health. In previous research, Heesch found that exercise and walking could boost physical and emotional health in women who are not depressed. © 2015 Scientific American
Link ID: 20536 - Posted: 01.31.2015
By KEN BELSON A new study of N.F.L. retirees found that those who began playing tackle football when they were younger than 12 years old had a higher risk of developing memory and thinking problems later in life. The study, published in the medical journal Neurology by researchers at the Boston University School of Medicine, was based on tests given to 42 former N.F.L. players, ages 41 to 65, who had experienced cognitive problems for at least six months. Half the players started playing tackle football before age 12, and the other half began at 12 or older. Those former N.F.L. players who started playing before 12 years old performed “significantly worse” on every test measure after accounting for the total number of years played and the age of the players when they took the tests. Those players recalled fewer words from a list they had learned 15 minutes earlier, and their mental flexibility was diminished compared with players who began playing tackle football at 12 or older. The age of 12 was chosen as a benchmark because it is roughly the point by which brains in young boys are thought to have already undergone key periods of development. Research has shown that boys younger than 12 who injure their brains can take longer to recover and have poor cognition in childhood. The findings are likely to fuel an already fierce debate about when it is safe to allow children to begin playing tackle football and other contact sports. Youth leagues are under scrutiny for putting children at risk with head injuries. Pop Warner and many other youth leagues have added training protocols, have limited contact in practice and have adjusted weight and age limits to try to reduce head injuries and the risks associated with them. But some leagues continue to allow children as young as 5 to play tackle football. © 2015 The New York Times Company
by Jessica Hamzelou WHAT doesn't kill you makes you stronger, at least when it comes to stress and immune cells. Mice that received a cocktail of immune cells from bullied mice appeared to experience a mood boost. The unexpected discovery may have implications for treating depression. We know that prolonged bouts of stress take their toll on the immune system. That leaves us susceptible to illness, which in some cases can lead to depression. Most research on the link between immune health and mood has focused on the innate branch of the immune system – the cells that mount the first response to pathogens, says Miles Herkenham at the National Institutes of Health in Bethesda, Maryland. His team wondered if there might also be a role for the adaptive branch of the immune system, which "learns" about a pathogen in order to respond rapidly the next time it appears. To find out, the team introduced an aggressive competitor mouse into the cages of male mice. "These mice are like bullies," says Herkenham. Two weeks later, the bullied mice seemed depressed: they cowered in dark corners and seemed uninterested in the scent of a female. The team extracted their adaptive immune cells and injected them into another set of mice bred to lack these cells. This meant that the recipient mice essentially acquired the adaptive immune system of the bullied ones. © Copyright Reed Business Information Ltd.
Ewen Callaway Since August 2014, more than 100 children and young adults in the United States have developed a mysterious paralysis. Many of them had fevers before losing strength in one or more limbs, and the cases coincided with a wider epidemic of a little-known respiratory pathogen. That virus, enterovirus D68 (EV-D68), is the leading candidate for the cause of the paralysis, which few children have recovered from. Yet researchers have not definitively linked the two, or determined how the virus could cause the children’s symptoms. A study published on 28 January in The Lancet1 that describes a cluster of cases from Denver, Colorado, strengthens the link, but falls short of providing a 'smoking gun'. Here is what we know about the virus — and what scientists are trying to find out. It belongs to the enterovirus family, which includes poliovirus and the pathogens that cause common colds; it is most similar to the rhinoviruses that cause respiratory infections. Although EV-D68 was first isolated in the 1960s, it is relatively uncommon among enteroviruses circulating worldwide. However, since August 2014, the virus has been linked to more than 1,000 respiratory infections in the United States, some of them severe, and France has seen cases, too. John Watson, a medical epidemiologist at the US Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, says that last year, EV-D68 was the predominant type of enterovirus circulating in the country. “That’s a first,” he says. Genome sequencing2 of viruses recovered from respiratory cases in St Louis, Missouri, shows that the EV-D68 strain circulating in the United States is most closely related to viruses that caused a pneumonia-like illness in three children in Thailand in 20113. What is the evidence that links EV-D68 to the cases of paralysis? © 2015 Nature Publishing Group
Keyword: Movement Disorders
Link ID: 20533 - Posted: 01.29.2015
By Michael Balter Our ancestors likely had sex with Neandertals, but when and where did these encounters take place? The discovery of a 55,000-year-old partial skull of a modern human in an Israeli cave, the first sighting of Homo sapiens in this time and place, offers skeletal evidence to support the idea that Neandertals and moderns mated in the Middle East between 50,000 and 60,000 years ago. What’s more, the skull could belong to an ancestor of the modern humans who later swept across Europe and Asia and replaced the Neandertals. The find supports a raft of recent genetic studies. A 2010 analysis, for example, found that up to 2% of the genomes of today’s Europeans and Asians consist of Neandertal DNA, a clear sign of at least limited interbreeding in the past. Two years later, scientists compared ancient DNA extracted from Neandertal fossils to that of contemporary modern human populations around the world, concluding that this interbreeding took place in the Middle East, most likely between 47,000 and 65,000 years ago. And last year, a 45,000-year-old modern human found in Siberia, the oldest modern to have its genome sequenced, was revealed to have harbored a little more than 2% Neandertal DNA, allowing researchers to refine the interbreeding event to roughly 50,000 to 60,000 years ago. From the Neandertal side, this time and place make sense. That’s because numerous skeletons dated to that time period have been found in caves in Israel and other parts of the Middle East over the years, and Neandertals were still living in the region as late as 49,000 years ago. Yet the other side of this mating partnership has been conspicuously absent from the fossil record of the Middle East. © 2015 American Association for the Advancement of Science
Link ID: 20532 - Posted: 01.29.2015
Criminal psychopaths learn to respond differently to punishment cues than others in jail and may need more reward-focused treatments, new research suggests. Criminals such as Paul Bernardo, Ted Bundy and Clifford Olson, who scored high on psychopathy checklists, were known to be callous and unemotional. Psychopaths derive pleasure from being manipulative and use premeditated aggression to get what they want with no regard for those who are hurt. The search for what makes them tick has shown some physical differences in their brains such as reductions in grey matter. Now researchers in London, Montreal and Bethseda, Md., have used functional MRI imaging to assess how the brains of 12 violent criminals with psychopathy, 20 violent criminals with antisocial personality disorder but not psychopathy (such as those with a history of impulsivity and risk-taking), and 18 healthy people who were not criminals responded differently to rewards and punishment. "In the room with them, there's the sense that the weight of what they've done and the deleterious effect this is having on their lives doesn't really hold for them," said Dr. Nigel Blackwood of King's College London, a senior author of the paper in Wednesday's issue of Lancet Psychiatry. It's only at the moment in the scanner when the sanction of lost points cues them to change their behaviour that the differences between violent psychopaths and those with antisocial personality disorder appear. ©2015 CBC/Radio-Canada
Sara Reardon The US National Institutes of Health (NIH) has modified the way a controversial lab studies stress in monkeys in response to criticism by animal-rights activists and members of Congress who say that the research is inhumane. At issue are experiments led by Stephen Suomi, a psychologist at the US National Institute of Child Health and Human Development (NICHD) in Poolesville, Maryland. Suomi’s lab studies how removing newborn rhesus macaques from their mothers affects biological processes such as brain activity and gene expression, and behaviours such as alcohol consumption in the infants. He has performed similar experiments for about three decades, and has received roughly US$30 million over the past seven years for the work, according to the activist group People for the Ethical Treatment of Animals (PETA), which obtained documents and videos from the lab through a freedom-of-information request. In September, PETA began posting ads in the subway station near NIH’s Bethesda, Maryland, campus, and in newspapers condemning the experiments as “cruel and archaic”, and arguing that they yielded results that were not relevant to human health. The group also posted video of NIH monkey experiments on its website. PETA’s campaign drew the attention of Congress. In December, four Democratic members of the House of Representatives wrote to the NIH, demanding that the agency’s Bioethics Commission investigate the Suomi lab’s practices and the justification for the experiments. “We know what the impact is when children are taken from their parents,” says one of the lawmakers, Lucille Roybal-Allard (Democrat, California). “While [animal] research is necessary in many cases, we can’t just do it without evaluation and having a clear purpose.” © 2015 Nature Publishing Group
By Nicholas Weiler If you find people watching oddly compelling, you’re not alone. A new study suggests that gregarious European starlings (Sturnus vulgaris) get a kick out of looking at their fellow birds, even if it’s just on a computer screen. Researchers took 10 captive starlings from their flock and isolated them for 4 days in a cage with plenty of food and water and a large flat-screen monitor. Most of the birds quickly discovered that poking their beaks into one sensor in the cage flashed a life-size photograph of an unknown starling onto the screen, while a second sensor produced a picture of a suburban landscape. The lonely birds seemed to enjoy looking at other starlings, the researchers found. On average, they triggered a new starling photo every 6 minutes, 7 hours a day, for 4 days. They only threw in a landscape every 20 minutes or so. It wasn’t just that the landscapes were boring. Given the choice between photos of starlings and photos of monkeys, a second group of five birds also pecked to view their own kind three times more often. The results suggest starlings have a natural yearning for social stimulation, the authors report online this month in Animal Cognition. In the future, starlings’ drive to view photos of one another could be used to study the social rewards that knit communities together. © 2015 American Association for the Advancement of Science
Alison Abbott If you have to make a complex decision, will you do a better job if you absorb yourself in, say, a crossword puzzle instead of ruminating about your options? The idea that unconscious thought is sometimes more powerful than conscious thought is attractive, and echoes ideas popularized by books such as writer Malcolm Gladwell’s best-selling Blink. But within the scientific community, ‘unconscious-thought advantage’ (UTA) has been controversial. Now Dutch psychologists have carried out the most rigorous study yet of UTA — and find no evidence for it. Their conclusion, published this week in Judgement and Decision Making, is based on a large experiment that they designed to provide the best chance of capturing the effect should it exist, along with a sophisticated statistical analysis of previously published data1. The report adds to broader concerns about the quality of psychology studies and to an ongoing controversy about the extent to which unconscious thought in general can influence behaviour. “The bigger debate is about how clever our unconscious is,” says cognitive psychologist David Shanks of University College London. “This carefully constructed paper makes a great contribution.” Shanks published a review last year that questioned research claiming that various unconscious influences, including UTA, affect decision making2. © 2015 Nature Publishing Group
|By Daniel Yudkin Imagine you are with some friends at a concert, and the bouncer approaches the group and says that, because you are all looking so ravishing tonight, he’s been instructed to offer one of you—just one!—a backstage pass to meet the artist. Do you raise your hand? For most people, this would be a no-brainer: who wouldn’t leap at the chance to meet a famous singer or secure a long-sought autograph? The results of a recent study, published in Psychological Science by Gus Cooney, Daniel Gilbert, and Timothy Wilson, however, suggest taking a second’s pause before snapping up that backstage pass. Cooney, Gilbert, and Wilson suspected that extraordinary experiences—like meeting a musical idol—carry hidden costs. They hypothesized that, while such occurrences undoubtedly make us happier in the moment, they also risk separating us from our peers, leading to a sense of isolation so unpleasant as to outweigh whatever enjoyment they initially confer. To test this idea, the researchers recruited subjects in groups of four and had them watch a video clip. Of the group, three were told that they would watch a clip that previous viewers had given a 2-star rating; the remaining subject, by contrast, was granted the opportunity to view a special 4-star clip. After watching the videos, all four subjects were given some time to talk amongst themselves, and then each reported on their general happiness. © 2015 Scientific American
Link ID: 20527 - Posted: 01.28.2015
Ian Sample, science editor People who carry a mutated gene linked to longer lifespan have extra tissue in part of the brain that seems to protect them against mental decline in old age. The finding has shed light on a biological pathway that researchers now hope to turn into a therapy that slows the progression of Alzheimer’s disease and other forms of dementia. Brain scans of more than 400 healthy men and women aged 53 and over found that those who carried a single copy of a particular gene variant had a larger brain region that deals with planning and decision making. Further tests on the group found that those with an enlarged right dorsolateral prefrontal cortex (rDLPFC), as the brain region is known, fared better on a series of mental tasks. About one in five people inherits a single copy of the gene variant, or allele, known as KL-VS, which improves heart and kidney function, and on average adds about three years to human lifespan, according to Dena Dubal, a neurologist at University of California, San Francisco. Her latest work suggests that the same genetic mutation has broader effects on the brain. While having a larger rDLPFC accounted for only 12% of the improvement in people’s mental test scores, Dubal suspects the gene alters the brain in other ways, perhaps by improving the connections that form between neurons.
/ by Tanya Lewis, LiveScience You know the feeling: the dryness in the mouth, the stickiness in the throat and the creeping salivation — thirst. But what causes feelings of thirst in the brain? In a new study, scientists used laser light to activate groups of neurons in the brains of mice. By targeting specific neuron groups, the scientists could make the animals drink even if they weren't thirsty, and stop drinking even if they were thirsty. Understanding how the brain causes feelings of thirst could help scientists learn what goes awry in disorders that make people drink too much or too little fluid, researchers say. "Thirst has attracted a lot of interest because it is such a basic function for all organisms," said Yuki Oka, a neuroscientist currently at the California Institute of Technology and co-author of the study published today (Jan. 26) in the journal Nature. Before this study, scientists knew which brain regions were activated by dehydration and hydration. "But key information was missing as to which were controlling thirst," Oka told Live Science. In the new study, Oka and a team of colleagues at Columbia University used a technique called optogenetics to pinpoint the origin of thirst impulses in the brains of mice. The researchers injected the mouse brains with a virus that made certain cells sensitive to laser light, and when scientists shone the laser on those cells, it caused them to turn nerve impulses "on" or "off." © 2015 Discovery Communications, LLC.
Link ID: 20525 - Posted: 01.28.2015