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For the first time, the barrier that protects the brain has been opened without damaging it, to deliver chemotherapy drugs to a tumour. The breakthrough could be used to treat pernicious brain diseases such as cancer, Parkinson’s and Alzheimer’s, by allowing drugs to pass into the brain. The blood-brain barrier keeps toxins in the bloodstream away from the brain. It consists of a tightly packed layer of endothelial cells that wrap around every blood vessel throughout the brain. It prevents the passage of viruses, bacteria and other toxins, while ushering in vital molecules such as glucose via specialised transport mechanisms. The downside of this is that the blood-brain barrier also blocks the vast majority of drugs. There are a few exceptions, but those drugs that are able to sneak through can also penetrate every cell in the body, which makes for major side effects. Now researchers at Sunnybrook Health Sciences Centre in Toronto, Canada, say they have successfully used ultrasound to temporarily open the blood-brain barrier, with the ultimate aim of treating a brain tumour. The procedure took place on 4 November. Ultrasound prises open brain's protective barrier for first time The team, led by neurosurgeon Todd Mainprize and physicist Kullervo Hynynen, injected the chemotherapy drug doxorubicin along with tiny gas-filled microbubbles, into the blood of a patient with a brain tumour. The microbubbles and the drug spread throughout their body, including into the blood vessels that serve the brain. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging; Parkinsons
Link ID: 21625 - Posted: 11.11.2015

By James Gallagher Health editor, BBC News website A mass vaccination programme against meningitis A in Africa has been a "stunning success", say experts. More than 220 million people were immunised across 16 countries in the continent's meningitis belt. In 2013 there were just four cases across the entire region, which once faced thousands of deaths each year. However, there are fresh warnings from the World Health Organization that "huge epidemics" could return unless a new vaccination programme is started. The meningitis belt stretches across sub-Saharan Africa from Gambia in the west to Ethiopia in the east. In the worst epidemic recorded, in 1996-97, the disease swept across the belt infecting more than a quarter of a million people and led to 25,000 deaths. Unlike other vaccines, the MenAfriVac was designed specifically for Africa and in 2010 a mass vaccination campaign was started. "The disease has virtually disappeared from this part of the world," said Dr Marie-Pierre Preziosi from the World Health Organization. The mass immunisation programme was aimed at people under 30. However, routine vaccination will be needed to ensure that newborns are not vulnerable to the disease. Projections, published in the journal Clinical Infectious Diseases, showed the disease could easily return. Dr Preziosi told the BBC News website: "What could happen is a huge epidemic that could sweep the entire area, that could target hundreds of thousands of people with 5-10% deaths at least. © 2015 BBC

Keyword: Miscellaneous
Link ID: 21624 - Posted: 11.11.2015

By Virginia Morell Plunge a live crab into a pot of boiling water, and it’s likely to try to scramble out. Is the crab’s behavior simply a reflex, or is it a sign of pain? Many scientists doubt that any invertebrate (or fish) feels pain because they lack the areas in the brain associated with human pain. Others argue this is an unfair comparison, noting that despite the major differences between vertebrate and invertebrate brains, their functions (such as seeing) are much the same. To get around this problem, researchers in 2014 argued that an animal could be classified as experiencing pain if, among other things, it changes its behavior in a way that indicates it’s trying to prevent further injury, such as through increased wariness, and if it shows a physiological change, such as elevated stress hormones. To find out whether crabs meet these criteria, scientists collected 40 European shore crabs (Carcinus maenas), shown in the photo above, in Northern Ireland. They placed the animals into individual tanks, and gave half 200-millisecond electrical shocks every 10 seconds for 2 minutes in their right and left legs. The other 20 crabs served as controls. Sixteen of the shocked crabs began walking in their tanks, and four tried to climb out. None of the control crabs attempted to clamber up the walls, but 14 walked, whereas six didn’t move at all. There was, however, one big physiological difference between the 16 shocked, walking crabs and the 14 control walkers, the scientists report in today’s issue of Biology Letters: Those that received electrical jolts had almost three times the amount of lactic acid in their haemolymph, a fluid that’s analogous to the blood of vertebrates—a clear sign of stress. Thus, crabs pass the bar scientists set for showing that an animal feels pain. © 2015 American Association for the Advancement of Science.

Keyword: Pain & Touch; Evolution
Link ID: 21623 - Posted: 11.11.2015

Laura Sanders In an unexpected twist, two antibodies designed to fight Alzheimer’s disease instead made nerve cells in mice misbehave more. The results, published online November 9 in Nature Neuroscience, highlight how little is known about how these drugs actually work, says study coauthor Marc Aurel Busche of Technical University Munich. “We need to understand what these antibodies do in the brains of patients better,” he says. The treatment approach relies on antibodies that target amyloid-beta, a protein that builds up in the brains of people with Alzheimer’s. One of the antibodies used in the new study, bapineuzumab, failed to show benefits in much-anticipated trials described in the New England Journal of Medicine in 2014. Despite that setback, some researchers say antibodies are still the best option to halt Alzheimer’s. The bapineuzumab trial was flawed, says neurologist Dennis Selkoe of Harvard Medical School and Brigham and Women’s Hospital. And the new results, which come from mice, have little relevance for ongoing tests of other antibodies in people, he says. “A-beta immunotherapy is the most promising approach right now, and nothing in their paper undercuts that,” he says. Several other antibodies have recently shown modest benefits in people with Alzheimer’s, he adds. Representatives from Eli Lilly and Biogen, pharmaceutical companies that are developing antibody treatments, declined to comment on the new study. © Society for Science & the Public 2000 - 2015

Keyword: Alzheimers; Neuroimmunology
Link ID: 21622 - Posted: 11.10.2015

By Simon Makin Optogenetics is probably the biggest buzzword in neuroscience today. It refers to techniques that use genetic modification of cells so they can be manipulated with light. The net result is a switch that can turn brain cells off and on like a bedside lamp. The technique has enabled neuroscientists to achieve previously unimagined feats and two of its inventors—Karl Deisseroth of Stanford University and the Howard Hughes Medical Institute and Ed Boyden of Massachusetts Institute of Technology—received a Breakthrough Prize in the life sciences on November 8 in recognition of their efforts. The technology is able to remotely control motor circuits—one example is having an animal run in circles at the flick of a switch. It can even label and alter memories that form as a mouse explores different environments. These types of studies allow researchers to firmly establish a cause-and-effect relationship between electrical activity in specific neural circuits and various aspects of behavior and cognition, making optogenetics one of the most widely used methods in neuroscience today. As its popularity soars, new tricks are continually added to the optogenetic arsenal. The latest breakthroughs, promise to deliver the biggest step forward for the technology since its inception. Researchers have devised ways of broadening optogenetics to enter into a dynamic dialogue with the signals moving about inside functioning brains. © 2015 Scientific American

Keyword: Brain imaging
Link ID: 21621 - Posted: 11.10.2015

By Arlene Karidis Several years ago, Peggy Chenoweth began having excruciating cramping in her ankle. It felt severely sprained and as if her toe were twisting to the point where it was being ripped off her foot. “The pain is right here,” she told an orthopedic surgeon, “in my ankle and foot.” But the 41-year-old Gainesville, Va., resident no longer had that ankle and foot. Her leg had been amputated below the knee after a large piece of computer equipment fell off a cart, crushed her foot and caused nerve damage. Further, she insisted that since the amputation, she could feel her missing toes move. Chenoweth’s surgeon knew exactly what was going on: phantom pain. Lynn Webster, an anesthesiologist and past president of the American Academy of Pain Medicine, explains the phenomenon: “With ‘phantom pain,’ nerves that transmitted information from the brain to the now-missing body part continue to send impulses, which relay the message of pain.” It feels as if the removed part is still there and hurting, but pain is actually in the brain. The sensation ranges from annoying itching to red-hot burning. Physicians wrote about phantom pain as early as the 1860s, but U.S. research on this condition has increased recently, spurred by the surge of amputees returning from warfare in Iraq and Afghanistan and by increasing rates of diabetes. (Since 2003, nearly 1,650 service members have lost limbs, according to the Congressional Research Service. In 2010, about 73,000 amputations were performed on diabetics in the United States, according to the Centers for Disease Control and Prevention.)

Keyword: Pain & Touch
Link ID: 21620 - Posted: 11.10.2015

By Jason G. Goldman When a monkey has the sniffles or a headache, it doesn't have the luxury of popping a few painkillers from the medicine cabinet. So how does it deal with the common colds and coughs of the wildlife world? University of Georgia ecologist Ria R. Ghai and her colleagues observed a troop of more than 100 red colobus monkeys in Uganda's Kibale National Park for four years to figure out whether the rain forest provides a Tylenol equivalent. Monkeys infected with a whipworm parasite were found to spend more time resting and less time moving, grooming and having sex. The infected monkeys also ate twice as much tree bark as their healthy counterparts even though they kept the same feeding schedules. The findings were published in September in the journal Proceedings of the Royal Society B. The fibrous snack could help literally sweep the intestinal intruder out of the simians' gastrointestinal tracts, but Ghai suspects a more convincing reason. Seven of the nine species of trees and shrubs preferred by sick monkeys have known pharmacological properties, such as antisepsis and analgesia. Thus, the monkeys could have been self-medicating, although she cannot rule out other possibilities. The sick individuals were, however, using the very same plants that local people use to treat illnesses, including infection by whipworm parasites. And that “just doesn't seem like a coincidence,” Ghai says. © 2015 Scientific American,

Keyword: Drug Abuse; Evolution
Link ID: 21619 - Posted: 11.10.2015

By Katherine Ellison Last year, Sinan Sonmezler of Istanbul refused to keep going to school. His eighth-grade classmates called him “weird” and “stupid,” and his teachers rebuked him for his tendency to stare out the window during class. The school director told his parents he was “lazy.” Sinan has attention-deficit hyperactivity disorder, a condition still little understood in many parts of the world. “He no longer believes he can achieve anything, and has quit trying,” said Sinan’s father, Umit Sonmezler, a mechanical engineer. While global diagnoses of A.D.H.D. are on the rise, public understanding of the disorder has not kept pace. Debates about the validity of the diagnosis and the drugs used to treat it — the same that have long polarized Americans — are now playing out from Northern and Eastern Europe to the Middle East and South America. Data from various nations tell a story of rapid change. In Germany, A.D.H.D. diagnosis rates rose 381 percent from 1989 to 2001. In the United Kingdom, prescriptions for A.D.H.D. medications rose by more than 50 percent in five years to 657,000 in 2012, up from 420,000 in 2007. Consumption of A.D.H.D. medications doubled in Israel from 2005 to 2012. The surge in use of the medications has prompted skepticism that pharmaceutical firms, chasing profits in an $11 billion international market for A.D.H.D. drugs, are driving the global increase in diagnoses. In 2007, countries outside the United States accounted for only 17 percent of the world’s use of Ritalin. By 2012, that number had grown to 34 percent. © 2015 The New York Times Company

Keyword: ADHD
Link ID: 21618 - Posted: 11.10.2015

By Michelle Roberts Health editor, BBC News online An increasingly warped sense of humour could be an early warning sign of impending dementia, say UK experts. The University College London study involved patients with frontotemporal dementia, with the results appearing in the Journal of Alzheimer's Disease. Questionnaires from the friends and family of the 48 patients revealed many had noticed a change in humour years before the dementia had been diagnosed. This included laughing inappropriately at tragic events. Experts say more studies are now needed to understand how and when changes in humour could act as a red flag for dementia. There are many different types of dementia and frontotemporal dementia is one of the rarer ones. The area of the brain it affects is involved with personality and behaviour, and people who develop this form of dementia can lose their inhibition, become more impulsive and struggle with social situations. Dr Camilla Clark and colleagues recruited 48 patients from their dementia clinic at University College London. And they asked the friends or relatives of the patients to rate their loved one's liking for different kinds of comedy - slapstick comedy such as Mr Bean, satirical comedy such as Yes, Minister or absurdist comedy such as Monty Python - as well as any examples of inappropriate humour. Nearly all of the respondents said, with hindsight, that they had noticed a shift in the nine years before the dementia had been diagnosed. Many of the patients had developed a dark sense of humour - for example, laughing at tragic events in the news or in their personal lives. The dementia patients also tended to prefer slapstick to satirical humour, when compared with 21 healthy people of a similar age. © 2015 BBC.

Keyword: Alzheimers
Link ID: 21617 - Posted: 11.10.2015

Angus Chen English bursts with consonants. We have words that string one after another, like angst, diphthong and catchphrase. But other languages keep more vowels and open sounds. And that variability might be because they evolved in different habitats. Consonant-heavy syllables don't carry very well in places like windy mountain ranges or dense rainforests, researchers say. "If you have a lot of tree cover, for example, [sound] will reflect off the surface of leaves and trunks. That will break up the coherence of the transmitted sound," says Ian Maddieson, a linguist at the University of New Mexico. That can be a real problem for complicated consonant-rich sounds like "spl" in "splice" because of the series of high-frequency noises. In this case, there's a hiss, a sudden stop and then a pop. Where a simple, steady vowel sound like "e" or "a" can cut through thick foliage or the cacophony of wildlife, these consonant-heavy sounds tend to get scrambled. Hot climates might wreck a word's coherence as well, since sunny days create pockets of warm air that can punch into a sound wave. "You disrupt the way it was originally produced, and it becomes much harder to recognize what sound it was," Maddieson says. "In a more open, temperate landscape, prairies in the Midwest of the United States [or in Georgia] for example, you wouldn't have that. So the sound would be transmitted with fewer modifications." © 2015 npr

Keyword: Language; Evolution
Link ID: 21616 - Posted: 11.07.2015

By Elahe Izadi The days growing shorter and colder can be more than just a nuisance; the seasonal change can also trigger clinical depression. Those who suffer from seasonal affective disorder, or SAD, may turn to a light box to help make them feel better. But a new study suggests another form of therapy could be more powerful and enduring: talking. The benefits of cognitive behavioral therapy — a form of talk therapy — outlasted light therapy sessions for people suffering from SAD, according to a study published Thursday in the American Journal of Psychiatry. "Light therapy is a treatment that suppresses symptoms as long as you're using it," said lead author Kelly Rohan, a psychology professor at the University of Vermont. "So if you're not using it, there's no reason to expect the continued benefit for a treatment that works that way, whereas cognitive behavioral therapy teaches skills." And the people who learn those skills can use them long after their therapy sessions. For the study, researchers tracked 177 people who suffer from major depression that follows a recurring seasonal pattern. About half of the subjects received six weeks of daily light therapy; the others received 12 sessions of cognitive behavioral therapy over the same period of time.

Keyword: Depression; Biological Rhythms
Link ID: 21615 - Posted: 11.07.2015

By Rachel E. Gross For decades, Michael Jackson had struggled to fall asleep at night. But in 2009 the pop singer was preparing for his worldwide comeback tour, and he couldn’t afford to be at anything less than 100 percent. Desperate for sleep, he convinced an unscrupulous physician to give it to him synthetically in the form of an anesthetic so strong that it sent him almost immediately into a “druglike coma.” At first, Jackson would wake up feeling refreshed. But the nightly injections conferred only the shadow of true sleep, with none of the deep, dream-filled REM cycles that his body needed. Soon he was fading fast, his mind and mood slipping away. Within two months Jackson was dead of an overdose. If that hadn’t killed him, doctors later testified during his wrongful death trial, he would have died of sleep deprivation. Jackson’s is a particularly dramatic case. But his struggle for oblivion rings true to anyone who has dealt with insomnia. “I’m for anything that gets you through the night,” Frank Sinatra once said, “be it prayer, tranquilizers, or a bottle of Jack Daniel’s.” If you have insomnia, you’ll understand this sentiment, and you’re not alone: Regular sleep eludes up to 15 percent of the population, making insomnia the most commonly diagnosed sleep problem in America. Fortunately, the nighttime affliction is becoming steadily less mysterious—at least from the perspective of neuroscience. While insomniacs toss and turn, researchers are finally starting to understand this elusive disease. As it turns out, chronic insomnia may be more hard-wired into our brains than we had thought, and indicative of larger differences that separate the brains of the sleepless from those who so effortlessly enter the land of dreams. © 2015 The Slate Group LLC

Keyword: Sleep
Link ID: 21614 - Posted: 11.07.2015

by Laura Sanders Babies’ minds are mysterious. Thoughts might be totally different in a brain that lacks words, and sensations might feel alien in a body so new. Are babies’ perceptions like ours, or are they completely different? Even if babies could talk, words would surely fail to convey what it’s like to experience, oh, every single thing for the first time. A recent paper offers a sliver of insight into young babies’ inner lives. The study, published October 19 in Current Biology, finds an example in which 4-month-old babies are happily oblivious to the external world. The research focuses on a perceptual trick that suckers adults and 6-month-old babies alike. When the hands are crossed, people often mistake which hand feels a touch. Let’s say your left hand (now crossed over to the right side of your body) gets a tickle. Your eyes would see a hand on the right side of your body get touched — a place usually claimed by your right hand, but now occupied by your left. Those mismatches between sight, touch and expectation can thwart you from quickly and correctly saying which hand was touched. Here’s the twist: 4-month-old babies don’t fall for this trick, Andrew Bremner of Goldsmiths, University of London and his colleagues found. In the experiment, a researcher would hold infants’ legs in either a crossed position or straight, while one of two remote-controlled buzzers taped to their feet tickled one foot. The researchers then watched which foot or leg wiggled as a result. If the buzzed foot moved, that meant that the baby got it right. © Society for Science & the Public 2000 - 2015.

Keyword: Development of the Brain; Pain & Touch
Link ID: 21613 - Posted: 11.07.2015

By Erika Beras From the backseat of a cab, the moves a driver makes may at times seem, let’s say, daring. In fact, cabbies may actually be better, more agile drivers than the rest of us. Because they know their streets so well. Previous research found that the hippocampus in the brain of a typical cab driver is enlarged. That’s the part of the brain used in navigation. But now a study confirms that learning detailed navigation information does indeed cause that part of the brain to grow. The findings are in the journal NeuroImage. Researchers had young adults who were not regular gamers play a driving simulation game. Some practiced maneuvering the same route 20 times, while other players were confronted with 20 different routes. The participants’ brains were scanned before they performed the simulated driving and again after. Researchers found that subjects who kept repeating the same route increased their speed more than those driving multiple routes. The single-route drivers were also much better able to put in order a sequence of random pictures taken along the way and to draw a map of the route. The investigators also found increases in the single-route drivers in the functional connectivity between the hippocampus and other parts of the brain involved with navigation. And the amount of change was directly related to the amount of improvement each participant displayed. © 2015 Scientific American

Keyword: Learning & Memory
Link ID: 21612 - Posted: 11.07.2015

By Kelli Whitlock Burton More than half of Americans over the age of 70 have cataracts, caused by clumps of proteins collecting in the eye lens. The only way to remove them is surgery, an unavailable or unaffordable option for many of the 20 million people worldwide who are blinded by the condition. Now, a new study in mice suggests eye drops made with a naturally occurring steroid could reverse cataracts by teasing apart the protein clumps. “This is a game changer in the treatment of cataracts,” says Roy Quinlan, a molecular biologist at Durham University in the United Kingdom who was not part of the study. “It takes decades for the cataracts to get to that point, so if you can reverse that by a few drops in the eye over a couple of weeks, that’s amazing.” The proteins that make up the human lens are among the oldest in the body, forming at about 4 weeks after fertilization. The majority are crystallins, a family of proteins that allow the eye to focus and keep the lens clear. Two of the most abundant crystallins, CRYAA and CRYAB, are produced in response to stress or injury. They act as chaperones, identifying and binding to damaged and misfolded proteins in the lens, preventing them from aggregating. But over the years, as damaged proteins accumulate in the lens, these chaperones become overwhelmed. The mutated proteins then clump together, blocking light and producing the tell-tale cloudiness of cataracts. © 2015 American Association for the Advancement of Science

Keyword: Vision
Link ID: 21611 - Posted: 11.06.2015

THINK twice before you tell that fib. By watching courtroom videos, a computer has learned to predict if someone is telling the truth or a lie. A machine learning algorithm trained on the faces of defendants in recordings of real trials, including that of Andrea Sneiderman (above) who was convicted of lying, correctly identified truth-tellers about 75 per cent of the time. Humans managed just 59.5 per cent. The best interrogators can reach 65 per cent. “We’re actually pretty bad lie detectors,” says Rada Mihalcea at the University of Michigan in Ann Arbor. Mihalcea and her colleagues took 121 videos from sources such as the Innocence Project, a non-profit group in Texas dedicated to exonerating people with wrongful convictions. This is superior to simulated conversation because the speakers are more invested in what they are saying. Transcriptions of the videos that included the speaker’s gestures and expressions were fed into a machine learning algorithm, along with the trial’s outcome. To hone it further, the team plans to feed in even more data. Such a system could one day spot liars in real-time in court or at airport customs, says Mihalcea, who will present the work at the International Conference on Multimodal Interaction this month in Seattle, Washington. © Copyright Reed Business Information Ltd.

Keyword: Emotions
Link ID: 21610 - Posted: 11.06.2015

Nancy Shute In September, we reported on a charming little study that found people who feel blue after watching sad videos have a harder time perceiving colors on the blue-yellow axis. Now the researchers may be feeling blue themselves. On Thursday they retracted their study, saying that errors in how they structured the experiment skewed the results. Shortly after the study was published online, commenters started looking skeptically at the results. And because the researchers had posted their data online, those commenters were able to run the numbers themselves. They didn't like what they found. As one blogger wrote: "A major problem is that the authors are claiming that they've found an interaction between video condition and color axis, but they haven't actually tested this interaction, they've just done a pair of independent t-tests and found different results." As the indefatigable crew at the Retraction Watch blog points out, it's not the first time scientists have messed this up. "This exact experimental oversight occurs all too often, according to a 2011 paper in Nature Neuroscience, which found that the same number of papers performed the procedure incorrectly as did it correctly." And there were other problems, too, such as not testing participants' color perception before the study. © 2015 npr

Keyword: Emotions; Vision
Link ID: 21609 - Posted: 11.06.2015

David Cyranoski A Chinese neuroscientist has been sacked after reporting he had used magnetic fields to control neurons and muscle cells in nematode worms (pictured), using a protein that senses magnetism. Tsinghua University in Beijing has sacked a neuroscientist embroiled in a dispute over work on a long-sought protein that can sense magnetic fields. The university has not given a specific reason for its dismissal, however, and the scientist involved, Zhang Sheng-jia, says that he will contest their action. In September, Zhang reported in the journal Science Bulletin1 that he could manipulate neurons in worms by applying a magnetic field — a process that uses a magnetic-sensing protein. But a biophysicist at neighbouring Peking University, Xie Can, who claims to have discovered the protein’s magnetic-sensing capacity and to have a paper detailing his research under review, complained that Zhang should not have published his paper before Xie’s own work appeared. Xie said that by publishing, Zhang violated an agreement that the pair had reached — although the two scientists tell different versions about the terms of their agreement, and have different explanations of how Zhang came to be working with the protein. © 2015 Nature Publishing Group

Keyword: Animal Migration
Link ID: 21608 - Posted: 11.06.2015

Paul Ibbotson and Michael Tomasello The natural world is full of wondrous adaptations such as camouflage, migration and echolocation. In one sense, the quintessentially human ability to use language is no more remarkable than these other talents. However, unlike these other adaptations, language seems to have evolved just once, in one out of 8.7 million species on earth today. The hunt is on to explain the foundations of this ability and what makes us different from other animals. The intellectual most closely associated with trying to pin down that capacity is Noam Chomsky. He proposed a universal grammatical blueprint that was unique to humans. This blueprint operated like a computer program. Instead of running Windows or Excel, this program performed “operations” on language – any language. Regardless of which of the 6000+ human languages that this code could be exposed to, it would guide the learner to the correct adult grammar. It was a bold claim: despite the surface variations we hear between Swahili, Japanese and Latin, they are all run on the same piece of underlying software. As ever, remarkable claims require remarkable evidence, and in the 50 years since some of these ideas were laid out, history has not been kind. First, it turned out that it is really difficult to state what is “in” universal grammar in a way that does justice to the sheer diversity of human languages. Second, it looks as if kids don’t learn language in the way predicted by a universal grammar; rather, they start with small pockets of reliable patterns in the language they hear, such as Where’s the X?, I wanna X, More X, It’s a X, I’m X-ing it, Put X here, Mommy’s X-ing it, Let’s X it, Throw X, X gone, I X-ed it, Sit on the X, Open X, X here, There’s a X, X broken … and gradually build their grammar on these patterns, from the “bottom up”. © 2015 Guardian News and Media Limited

Keyword: Language
Link ID: 21607 - Posted: 11.06.2015

Laura Sanders Specialized cells that make up the brain’s GPS system have an expanding job description. In addition to mapping locations, these cells can keep track of distance and time, too, scientists report in the Nov. 4 Neuron. Those specialized cells, called grid cells, were thought to have a very specific job, says neuroscientist Loren Frank of the University of California, San Francisco. But, he says, the new study says, “not so fast, everybody.” These cells’ ability to detect time and distance is unexpected. “And I think it’s important,” Frank says. The growing to-do list of grid cells shows that the brain’s navigational system is surprisingly flexible. The discovery of grid cells, found in a part of the brain called the entorhinal cortex, was recognized with the Nobel Prize last year (SN Online: 10/6/14). These brain cells fire off regular signals as animals move around in space, partially forming an internal map of the environment. Neuroscientist Howard Eichenbaum of Boston University and colleagues wondered what those cells do when an animal stays put. By training rats to run on a treadmill, the researchers had a way to study grid cells as time and distance marched forward, but location remained the same. Unlike recently discovered “speed cells” (SN: 8/8/15, p. 8), these grid cells don’t change their firing rates to correspond to changes in the rats’ swiftness, the researchers found. Instead, these cells stay tuned to distance or time, or both. © Society for Science & the Public 2000 - 2015.

Keyword: Learning & Memory
Link ID: 21606 - Posted: 11.05.2015