by Helen Thompson Narwhals use highly targeted beams of sound to scan their environment for threats and food. In fact, the so-called unicorns of the sea (for their iconic head tusks) may produce the most refined sonar of any living animal. A team of researchers set up 16 underwater microphones to eavesdrop on narwhal click vocalizations at 11 ice pack sites in Greenland’s Baffin Bay in 2013. The recordings show that narwhal clicks are extremely intense and directional — meaning they can widen and narrow the beam of sound to find prey over long and short distances. It’s the most directional sonar signal measured in a living species, the researchers report November 9 in PLOS ONE. The sound beams are also asymmetrically narrow on top. That minimizes clutter from echoes bouncing off the sea surface or ice pack. Finally, narwhals scan vertically as they dive, which could help them find patches of open water where they can surface and breathe amid sea ice cover. All this means that narwhals employ pretty sophisticated sonar. The audio data could help researchers tell the difference between narwhal vocalizations and those of neighboring beluga whales. It also provides a baseline for assessing the potential impact of noise pollution from increases in shipping traffic made possible by sea ice loss. |© Society for Science & the Public 2000 - 2016.

Keyword: Hearing
Link ID: 22856 - Posted: 11.12.2016

By John Bohannon When it comes to influential neuroscience research, University College London (UCL) has a lot to boast about. That's not the opinion of a human but rather the output of a computer program that has now parsed the content of 2.5 million neuroscience articles, mapped all of the citations between them, and calculated a score of each author's influence on the rest. Three of the top 10 most influential (see table below) neuroscientists hail from UCL: Karl Friston (1st), Raymond Dolan (2nd), and Chris Frith (7th). The secret of their success? "We got into human functional brain imaging very early," Frith says. Getting in early made it possible to "be first to do many of the obvious studies." The program, called Semantic Scholar, is an online tool built at the Allen Institute for Artificial Intelligence (AI2) in Seattle, Washington. When it debuted in April, it calculated the most influential computer scientists based on 2 million papers from that field. Since then, the AI2 team has expanded the corpus to 10 million papers, 25% of which are from neuroscience. They hope to expand that to all of the biomedical literature next year, over 20 million papers. When Semantic Scholar looks at a paper published online, what does it actually see? Much more than the typical academic search engine, says Oren Etzioni, CEO of AI2 who has led the project. "We are using machine learning, natural language processing, and [machine] vision to begin to delve into the semantics." © 2016 American Association for the Advancement of Science

Keyword: Miscellaneous
Link ID: 22855 - Posted: 11.12.2016

Ian Sample Science editor Partially-paralysed monkeys have learned to walk again with a brain implant that uses wireless signals to bypass broken nerves in the spinal cord and reanimate the useless limbs. The implant is the first to restore walking ability in paralysed primates and raises the prospect of radical new therapies for people with devastating spinal injuries. Scientists hope the technology will help people who have lost the use of their legs, by sending movement signals from their brains to electrodes in the spine that activate the leg muscles. One rhesus macaque that was fitted with the new implant regained the ability to walk only six days after it was partially paralysed in a surgical procedure that severed some of the nerves that controlled its right hind leg. “It was a big surprise for us,” said Grégoire Courtine, a neuroscientist who led the research at the Swiss Federal Institute of Technology. “The gait was not perfect, but it was almost like normal walking. The foot was not dragging and it was fully weight bearing.” A second animal in the study that received more serious damage to the nerves controlling its right hind leg recovered the ability to walk two weeks after having the device fitted, according to a report published in the journal, Nature. Both monkeys regained full mobility in three months. The “brain-spine interface” is the latest breakthrough to come from the rapidly-advancing area of neuroprosthetics. Scientists in the field aim to read intentions in the brain’s activity and use it to control computers, robotic arms and even paralysed limbs. © 2016 Guardian News and Media Limited

Keyword: Movement Disorders; Robotics
Link ID: 22854 - Posted: 11.10.2016

Geoff Brumfiel Scientists have pinpointed the ticklish bit of a rat's brain. The results, published in the journal Science, are another step toward understanding the origins of ticklishness, and its purpose in social animals. Although virtually every human being on the planet has been tickled, scientists really don't understand why people are ticklish. The idea that a certain kind of touching could easily lead to laughter is confusing to a neuroscientist, says Shimpei Ishiyama, a postdoc at the Berstein Center for Computational Nueroscience in Berlin, Germany. "Just a physical touch inducing such an emotional output — this is very mysterious," Ishiyama says. "This is weird." To try and get a handle on how tickling works, Ishiyama studied rats, who seem to enjoy being tickled, according to previous research. He inserted electrodes into the rats' brains, in a region called their somatosensory cortex. When rats enjoy tickling they emit high-pitched "laughter" that can't normally be heard by humans, the scientists found. In this video, the researchers transposed the audio of the squeaks to a lower frequency you can hear. That's a part of the brain that processes touch, and when Ishiyama tickled the rats, it caused neurons in that region to fire. The rats also seemed to giggle hysterically, emitting rapid-fire, ultrasonic squeaks. Earlier research has shown rats naturally emit those squeaks during frisky social interaction, such as when they are playing with other rats. © 2016 npr

Keyword: Emotions; Evolution
Link ID: 22853 - Posted: 11.10.2016

By Alison F. Takemura In the 1980s, neuroscientists were facing an imaging problem. They had developed a new way to detect neuronal activity with calcium dyes, but visualizing the markers proved challenging. The dyes fluoresced in the presence of calcium ions when illuminated with ultraviolet (UV) light, but it was difficult to build UV lenses for confocal microscopes—instruments that allowed scientists to peer hundreds of micrometers deep into the brain. To make matters worse, because biological tissue scatters light so effectively, confocal scopes required excessive light intensities, which caused irreparable damage to samples. “You basically burned your tissue,” says Winfried Denk, director of the Max Planck Institute of Neurobiology in Martinsried, Germany. The time was ripe for a gentler option, and Denk developed two-photon excitation microscopy in 1990. Instead of using a single photon to excite a calcium dye, scientists could use two photons and half the illumination energy—red or infrared lasers, instead of ultraviolet. The scatter of such low-energy rays caused far less damage to surrounding tissue. The technology had another advantage. To excite a molecule, both photons had to reach it simultaneously. This meant the laser could only excite a tiny patch of tissue where its photons were most concentrated, giving scientists a new level of precision. © 1986-2016 The Scientist

Keyword: Brain imaging
Link ID: 22852 - Posted: 11.10.2016

Kathleen Taylor The global rise in dementia should surprise no one. The figures — such as the 9.9 million new diagnoses each year — have been known for decades. As slow as we are to accept such vast changes on a personal, societal and political level, so research is slow to uncover why our brains become fragile with age. Neuroscientist and writer Kathleen Taylor's The Fragile Brain is about that research. But it is much more than a simple reflection on the best published hypotheses. Taylor has crafted a personal, astonishingly coherent review of our current state of knowledge about the causes of Alzheimer's disease and dementia, as well as possible solutions, from lifestyle adjustments to drug developments. Filled with elegant metaphors, her study covers the detail of molecular biology and larger-scale analysis, including epidemiological observations and clinical studies. It extends to dementia due to multiple sclerosis, stroke and encephalitis. For instance, some 5–30% of people who have a first stroke develop dementia. But the book's focus is Alzheimer's disease, and rightly so: it is what up to 80% of people with dementia are diagnosed with. Taylor begins with a shocking juxtaposition, setting the costs of age-related disorders and of dementia alongside the scarcity in funding. In Britain, Australia and the United States, for example, funding for dementia research is a fraction of that for cancer — in the United States, just 18%. She contextualizes with reflections on the history of dementia research, deftly unravelling the roles of pioneering scientists Alois Alzheimer, Franz Nissl and Emil Kraepelin in describing the condition. © 2016 Macmillan Publishers Limited,

Keyword: Alzheimers; Learning & Memory
Link ID: 22851 - Posted: 11.10.2016

By Anna Azvolinsky In January 1983, 22-year-old Amita Sehgal arrived in New York City from India to visit her oldest sister, who was due to have a baby. Sehgal had just been rejected from the molecular biology PhD programs at Rockefeller University and Columbia University. “I felt that I had no prospects,” says the University of Pennsylvania professor of neuroscience. She had heard about a Cornell University in NYC, so she and her other sister walked the streets of Manhattan asking its whereabouts. “Someone told us Cornell was hundreds of miles away in Ithaca, and that I must have been asking about the medical school. I had no idea, but I said ‘Yes’ and was directed to the Upper East Side.” Sehgal walked into the medical school, inquired about their PhD program, and was told that the application deadline for the program was that very day. “I sat in the office and filled out the application, wrote my essay, and handed it in!” she says. A few months later, Sehgal was admitted into the genetics program. Sehgal’s parents had also joined the visit and were returning to India in July, shortly before she started the PhD program. “It was fortuitous the way things worked out. My parents were comfortable leaving me in New York because my oldest sister was living there.” One month later, however, her sister and family moved to Florida, and Sehgal was alone, living in Cornell housing. “The first six months were really, really rough,” she says. Cornell had dissolved the genetics program to which Sehgal had been admitted and offered her tuition support with no stipend—and that only for the first semester. “My parents and sister were in no position to help me financially,” she says. Sehgal found a professor at the adjacent Memorial Sloan Kettering Cancer Center (MSKCC), Raju Chaganti, who gave her part-time work with no expectation that she join his lab. She had little money and survived on ramen noodles. © 1986-2016 The Scientist

Keyword: Sleep
Link ID: 22850 - Posted: 11.10.2016

By LESLEY ALDERMAN Take a deep breath, expanding your belly. Pause. Exhale slowly to the count of five. Repeat four times. Congratulations. You’ve just calmed your nervous system. Controlled breathing, like what you just practiced, has been shown to reduce stress, increase alertness and boost your immune system. For centuries yogis have used breath control, or pranayama, to promote concentration and improve vitality. Buddha advocated breath-meditation as a way to reach enlightenment. Science is just beginning to provide evidence that the benefits of this ancient practice are real. Studies have found, for example, that breathing practices can help reduce symptoms associated with anxiety, insomnia, post-traumatic stress disorder, depression and attention deficit disorder. “Breathing is massively practical,” says Belisa Vranich, a psychologist and author of the book “Breathe,” to be published in December. “It’s meditation for people who can’t meditate.” How controlled breathing may promote healing remains a source of scientific study. One theory is that controlled breathing can change the response of the body’s autonomic nervous system, which controls unconscious processes such as heart rate and digestion as well as the body’s stress response, says Dr. Richard Brown, an associate clinical professor of psychiatry at Columbia University and co-author of “The Healing Power of the Breath.” Consciously changing the way you breathe appears to send a signal to the brain to adjust the parasympathetic branch of the nervous system, which can slow heart rate and digestion and promote feelings of calm as well as the sympathetic system, which controls the release of stress hormones like cortisol. © 2016 The New York Times Company

Keyword: Stress
Link ID: 22849 - Posted: 11.09.2016

Elie Dolgin There are not a lot of things that could bring together people as far apart on the US political spectrum as Republican Newt Gingrich and Democrat Bob Kerrey. But in 2007, after leading a three-year commission that looked into the costs of care for elderly people, the political rivals came to full agreement on a common enemy: dementia. At the time, there were fewer than 30 million people worldwide diagnosed with the condition, but it was clear that the numbers were set to explode. By 2050, current predictions suggest, it could reach more than 130 million, at which point the cost to US health care alone from diseases such as Alzheimer’s will probably hit US$1 trillion per year in today’s dollars. “We looked at each other and said, ‘You know, if we don’t get a grip on Alzheimer’s, we can’t get anything done because it’s going to drown the system,’” recalls Gingrich, the former speaker of the US House of Representatives. He still feels that sense of urgency, and for good reason. Funding has not kept pace with the scale of the problem; targets for treatments are thin on the ground and poorly understood; and more than 200 clinical trials for Alzheimer’s therapies have been terminated because the treatments were ineffective. Of the few treatments available, none addresses the underlying disease process. “We’re faced with a tsunami and we’re trying to deal with it with a bucket,” says Gingrich. But this message has begun to reverberate around the world, which gives hope to the clinicians and scientists. Experts say that the coming wave can be calmed with the help of just three things: more money for research, better diagnostics and drugs, and a victory — however small — that would boost morale. © 2016 Macmillan Publishers Limited

Keyword: Alzheimers
Link ID: 22848 - Posted: 11.09.2016

Nancy Shute Erik Vance didn't go to a doctor until he was 18; he grew up in California in a family that practiced Christian Science. "For the first half of my life, I never questioned the power of God to heal me," Vance writes in his new book, Suggestible You: Placebos, False Memories, Hypnosis, and the Power of Your Astonishing Brain. As a young man, Vance left the faith behind, but as he became a science journalist he didn't stop thinking about how people's beliefs and expectations affect their health, whether it's with placebo pills, mystical practices or treatments like acupuncture. The answer, he found, is in our brains. Erik and I chatted about the book while attending a recent meeting of the National Association of Science Writers. Here are highlights of our conversation, edited for length and clarity. You point out that even though most of us didn't grow up Christian Scientist, we often use belief to manage our health. I've learned from writing this book that there are a lot of people around the world who really rely on expectation and placebos. And I grew up in the most extreme possible group, but it's not that different from seeing a homeopath. You're using faith to manage your body; what a psychologist would call expectation. Having had that experience really prepared me to ask some of these questions. How would your mom take care of you when you were sick? As a kid we might have 7UP with orange juice; we might go that far because it made you feel better. But the treatment was to call a practitioner, to call a healer. © 2016 npr

Keyword: Pain & Touch
Link ID: 22847 - Posted: 11.09.2016

Sara Reardon Major brain-mapping projects have multiplied in recent years, as neuroscientists develop new technologies to decipher how the brain works. These initiatives focus on understanding the brain, but the World Health Organization (WHO) wants to ensure that they work to translate their early discoveries and technological advances into tests and treatments for brain disorders. “We think there are side branches from projects that could be pursued with a very small investment to benefit public health,” says Shekhar Saxena, director of the WHO’s mental-health and substance-abuse department. Saxena will make that case on 12 November at the annual meeting of the Society for Neuroscience in San Diego, California — continuing a discussion that began in July at the WHO’s headquarters in Geneva, Switzerland. Among the roughly 70 people who attended that first meeting were leaders of the major brain initiatives, including the US BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative, launched in 2013; the European Human Brain Project, started in 2013; and the Japanese Brain/MINDS project, launched in 2014. All of these projects focus on basic research on the brain or the development of sophisticated tools to study it. Clinical applications are an ultimate, rather than an immediate, goal. But at the Geneva meeting, project leaders agreed, in principle, that they should do more to adapt brain-imaging technologies for use in clinical diagnoses. “The WHO is concerned that the emphasis on building these very expensive devices could worsen the health disparities that we have now between the developed and underdeveloped world,” says Walter Koroshetz, director of the US National Institute of Neurological Disorders and Stroke, which is part of the BRAIN Initiative. © 2016 Macmillan Publishers Limited

Keyword: Brain imaging
Link ID: 22846 - Posted: 11.09.2016

By STEPH YIN Neanderthals and modern humans diverged from a common ancestor about half a million years ago. Living in colder climes in Eurasia, Neanderthals evolved barrel chests, large skulls and strong hands. In Africa, modern humans acquired shorter faces, a prominent chin and slender limbs. Then, roughly 50,000 years ago, the two species encountered one another and interbred, as modern humans spread out of Africa. The legacy of this interbreeding has been the subject of much scientific inquiry in the past few years. Today, up to 4 percent of the genes of non-Africans are Neanderthal in origin.. These may have influenced a diverse range of traits, including keratin production, disease risk and the propensity to sneeze after eating dark chocolate. Where did all the other Neanderthal DNA go? Why did a Neanderthal-human hybrid not prevail? Two recent studies converge on an explanation. They suggest the answer comes down to different population sizes between Neanderthals and modern humans, and this principle of population genetics: In small populations, natural selection is less effective. “Neanderthals have this small population over hundreds of thousands of years, presumably because they’re living in very rough conditions,” said Graham Coop, a genetics professor at the University of California, Davis, and an author of one of the studies, published Tuesday in PLOS Genetics. As a result, Neanderthals were more inbred than modern humans and accumulated more mutations that have a slightly adverse effect, such as increasing one’s risk of disease, but do not prevent one from reproducing (and thus, passing such mutations along). © 2016 The New York Times Company

Keyword: Evolution; Genes & Behavior
Link ID: 22845 - Posted: 11.09.2016

Ian Sample Science editor US military scientists have used electrical brain stimulators to enhance mental skills of staff, in research that aims to boost the performance of air crews, drone operators and others in the armed forces’ most demanding roles. The successful tests of the devices pave the way for servicemen and women to be wired up at critical times of duty, so that electrical pulses can be beamed into their brains to improve their effectiveness in high pressure situations. The brain stimulation kits use five electrodes to send weak electric currents through the skull and into specific parts of the cortex. Previous studies have found evidence that by helping neurons to fire, these minor brain zaps can boost cognitive ability. The technology is seen as a safer alternative to prescription drugs, such as modafinil and ritalin, both of which have been used off-label as performance enhancing drugs in the armed forces. But while electrical brain stimulation appears to have no harmful side effects, some experts say its long-term safety is unknown, and raise concerns about staff being forced to use the equipment if it is approved for military operations. Others are worried about the broader implications of the science on the general workforce because of the advance of an unregulated technology. © 2016 Guardian News and Media Limited

Keyword: Learning & Memory; Sleep
Link ID: 22844 - Posted: 11.08.2016

By Simon Oxenham Isy Suttie has felt “head squeezing” since she was young. The comedian, best known for playing Dobbie in the BBC sitcom Peep Show, is one of many people who experience autonomous sensory meridian response (ASMR) – a tingly feeling often elicited by certain videos or particular mundane interactions. Growing up, Suttie says she had always assumed everyone felt it too. Not everyone feels it, but Suttie is by no means alone. On Reddit, a community of more than 100,000 members share videos designed to elicit the pleasurable sensation. The videos, often described as “whisper porn”, typically consist of people role-playing routine tasks, whispering softly into a microphone or making noises by crinkling objects such as crisp packets. The most popular ASMR YouTuber, “Gentle Whispering”, has over 250 million views. To most of us, the videos might seem strange or boring, but the clips frequently garner hundreds of thousands of views. These videos often mimic real-life situations that provoke ASMR in susceptible people. Suttie says her strongest real-world triggers occur during innocuous interactions with strangers, like talking about the weather – “it’s almost as if the more superficial the subject the better,” Suttie says. She feels the sensation particularly strongly when someone brushes past her. For Suttie, the feelings are so powerful that she often feels floored by them, and they even overcome pain and emotional distress. During a trip to the dentist, she still experiences the pleasurable tingles when the assistant brushes past her, she says. © Copyright Reed Business Information Ltd.

Keyword: Vision; Sexual Behavior
Link ID: 22843 - Posted: 11.08.2016

Anesthesia during early childhood surgery poses little risk for intelligence and academics later on, the largest study of its kind suggests. The results were found in research on nearly 200,000 Swedish teens. School grades were only marginally lower in kids who'd had one or more common surgeries with anesthesia before age 4, compared with those who'd had no anesthesia during those early years. Whether the results apply to sicker children who have riskier surgeries with anesthesia is not known. But the researchers from Sweden's Karolinska Institute and doctors elsewhere called the new results reassuring, given experiments in young animals linking anesthesia drugs with brain damage. Previous studies of children have been relatively small, with conflicting results. The new findings, published Monday in JAMA Pediatrics, don't provide a definitive answer and other research is ongoing. The study authors and other doctors say the harms from postponing surgery must be considered when evaluating any potential risks from anesthesia in young children. The most common procedures in the study were hernia repairs; ear, nose or throat surgeries; and abdominal operations. The researchers say the operations likely lasted an hour or less. The study did not include children with other serious health problems and those who had more complex or risky operations, including brain, heart and cancer surgeries. The research involved about 33,500 teens who'd had surgery before age 4 and nearly 160,000 who did not. ©2016 CBC/Radio-Canada.

Keyword: Development of the Brain; Sleep
Link ID: 22842 - Posted: 11.08.2016

By Jessica Boddy Glasses may be trendy now, but for centuries they were the stodgy accessories of the elderly worn only for failing eyes. Now, new research suggests that aging bonobos might also benefit from a pair of specs—not for reading, but for grooming. Many older bonobos groom their partners at arm’s length instead of just centimeters away, in the same way that older humans often hold newspapers farther out to read. This made researchers think the apes might also be losing their close-up vision as they age. To see whether their hypothesis held, the researchers took photos of 14 different bonobos of varying ages as they groomed one another (above) and measured the distance between their hands and faces. By analyzing how this so-called grooming distance varied from ape to ape, the researchers found that grooming distance increased exponentially with age, they report today in Current Biology. And because both humans and bonobos shows signs of farsightedness around age 40, deterioration in human eyes might not be the mere result of staring at screens and small text, the scientists say. Rather, it might be a deep-rooted natural trait reaching back to a common ancestor. © 2016 American Association for the Advancement of Science.

Keyword: Vision
Link ID: 22841 - Posted: 11.08.2016

By Felicity Muth Kirsty Graham is a PhD student at the University of St Andrews, Scotland, who works on gestural communication of chimpanzees and bonobos in Uganda and DRCongo. I recently asked her some questions about the work that she does and some exciting recent findings of hers about how these animals communicate. How did you become interested in communication, and specifically gestures? Languages are fascinating – the diversity, the culture, the learning – and during undergrad, I became interested in the origins of our language ability. I went to Quest University Canada (a small liberal arts university) and learned that I could combine my love of languages and animals and being outdoors! Other great apes don’t have language in the way that humans do, but studying different aspects of communication, such as gestures, may reveal how language evolved. Although my interest really started from an interest in languages, once you get so deep into studying other species you become excited about their behaviour for its own sake. In the long run, it would be nice to piece together how language evolved, but for now I’m starting with a very small piece of the puzzle – bonobo gestures. How do you study gestures in non-human primates? There are a few different approaches to studying gestures: in the wild or in captivity; through observation or with experiments; studying one gesture in detail or looking at the whole repertoire. I chose to observe wild bonobos and look at their whole repertoire. Since not much is known about bonobo gestural communication, this seemed like a good starting point. During my PhD, I spent 12 months at Wamba (Kyoto University’s research site) in the DRCongo. I filmed the bonobos, anticipating the beginning of social interactions so that I could record the gestures that they use. Then I spent a long time watching the videos, finding gestures, and coding information about the gestures. © 2016 Scientific American

Keyword: Language; Evolution
Link ID: 22840 - Posted: 11.07.2016

By LISA SANDERS, M.D. Yesterday we challenged Well readers to take on the case of a 63-year-old artist who, over the course of several months, developed excruciating headaches, along with changes in his personality, his thinking, even in the way he painted. We provided you with some of the doctor’s notes and medical imaging results that led the doctor who finally made the diagnosis in the right direction. After an extensive evaluation, that doctor asked a single question that led him to make the diagnosis. We asked Well readers to figure out the question the doctor asked and the diagnosis it suggested. It must have been a tough case — or else you were all too worried about the coming election to rise to the challenge — because we got just over 200 responses, fewer than usual. Of those, only six of you figured out the right diagnosis, and only three of you got the question right as well. Despite that, I was very impressed by the thinking of even those who didn’t come up with the right diagnosis. Many of you thought about environmental factors like his recent retirement and his exposure to possible toxins from his painting, and that kind of thinking was, in my opinion, the very essence of thinking like a doctor. Strong work, all of you. The question the doctor asked that led him to the correct diagnosis was: Can you hear your heartbeat in your ears? The patient could. And that suggested the diagnosis: A dural-arteriovenous fistula, or DAVF © 2016 The New York Times Company

Keyword: Pain & Touch
Link ID: 22839 - Posted: 11.07.2016

By Esther Crawley We know almost nothing about chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME). And yet it causes misery and suffering for hundreds of thousands of people, including many children. One in a hundred teenagers in the UK miss a day a week or more of school because of it, and 2 per cent are probably missing out on the normal stuff that teenagers do. Those I see in my clinic are sick with disabling fatigue, memory and concentration problems, and terrible pain. On average, they miss a year of school, on top of which mothers give up work and siblings suffer. Yet progress on this illness is being hampered by controversy, with some people disputing both its cause and treatment. Some still dismiss it as a non-illness; others decry attempts to treat it with psychological therapy. The result is that few patients are offered treatment and there is almost no research on the condition. This illness is more common than leukaemia and more disabling than childhood arthritis, but few specialists treat it. How have we arrived at a position where the biggest reason for teenagers to miss school long-term is rarely studied and society allows so few to receive treatment? Part of the difficulty is that CFS/ME is not a single illness. Both children and adults have different clusters of symptoms that may represent different illnesses with different biology, requiring different treatments. This may explain why treatments only work for some – and is a problem for those trying to develop them and for people who don’t get better. © Copyright Reed Business Information Ltd.

Keyword: Depression; Neuroimmunology
Link ID: 22838 - Posted: 11.07.2016

By Neuroskeptic A new paper could prompt a rethink of a basic tenet of neuroscience. It is widely believed that the motor cortex, a region of the cerebral cortex, is responsible for producing movements, by sending instructions to other brain regions and ultimately to the spinal cord. But according to neuroscientists Christian Laut Ebbesen and colleagues, the truth may be the opposite: the motor cortex may equally well suppress movements. Ebbesen et al. studied the vibrissa motor cortex (VMC) of the rat, an area which is known to be involved in the movement of the whiskers. First, they determined that neurons within the VMC are more active during periods when the rat’s whiskers are resting: for instance, like this: whiskerThe existence of cells whose firing negatively correlates with movement is interesting, but by itself it doesn’t prove that much. Maybe those cells are just doing something else than controlling movement? However, Ebbesen et al. went on to show that electrical stimulation of the VMC caused whiskers to stop moving, while applying a drug (lidocaine) to suppress VMC activity caused the rat’s whiskers to whisk harder. Ebbesen et al. go on to say that the inhibitory role of VMC may extend to other regions of the rat motor cortex, and to other movements beyond the whiskers: Rats can perform long sequences of skilled, learned motor behaviors after motor cortex ablation, but motor cortex is required for them to learn a task of behavioral inhibition (they must learn to postpone lever presses)35. When swimming, intact rats hold their forelimbs still and swim with only their hindlimbs. After forelimb motor cortex lesions, however, rats swim with their forelimbs also36.

Keyword: Movement Disorders
Link ID: 22837 - Posted: 11.07.2016