By Ben Hirschler LONDON (Reuters) - It's not all in the mind -- the so-called placebo effect is real and reaches right down to the spine, German scientists said on Thursday. The finding may help in the hunt for better ways to tackle pain and other disorders. Using modern imaging technology the researchers found that simply believing a pain treatment is effective actually dampens pain signaling in a region of the spinal cord called the dorsal horn, suggesting a powerful biological mechanism is at work. "It is deeply rooted in very, very early areas of the central nervous system. That definitely speaks for a strong effect," lead researcher Falk Eippert of the University Medical Center Hamburg-Eppendorf told Reuters. Eippert and colleagues used functional magnetic resonance imaging, or fMRI, to study changes in spinal cord activity. They applied painful heat to the arms of 15 healthy men and compared the spinal cord responses when they thought they had been treated with either an anesthetic cream or a placebo. Both creams, in fact, were inactive but the fMRI scans showed nerve activity was reduced significantly when subjects believed they were getting the anesthetic.

Keyword: Pain & Touch
Link ID: 13361 - Posted: 10.16.2009

By Tina Hesman Saey Honey’s sweet smell attracts more flies than does vinegar’s sour odor, but the ultimate fruit-fly magnet is eau de nothing. Ditching pheromones makes male and female fruit flies super-sexy to male flies, even to males of other species, Joel Levine, a neurogeneticist at the University of Toronto at Mississauga, and his colleagues report in the October 15 Nature. The discovery suggests pheromones can be back-off rather than come-hither signals. The finding could lead to a better understanding of the chemical signals that help flies and other animals interpret the world, including how to select a mate and how to distinguish other species. “It’s a very careful paper,” says Nicolas Gompel, a neurogeneticist at the Developmental Biology Institute of Marseilles-Luminy in France. “I think it’s raising the bar in the field because of the clarity of the analysis.” Typically fruit flies meet each other over rotten fruit. Often several species of fruit flies mill about the same location. Many of the species look very similar, at least to human eyes. “We geneticists can hardly tell them apart unless we dissect them,” Gompel says. It was a mystery how fruit flies could tell their own species from others. Scientists thought that sight and sound probably played big roles in distinguishing both species and gender. © Society for Science & the Public 2000 - 2009

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 13360 - Posted: 06.24.2010

By Rachel Ehrenberg The light, sparkly fizz of champagne owes its taste to the tongue’s sense of sour. New studies in mice reveal how the tongue tastes carbonation, solving an old puzzle of why some mountain climbers get the “champagne blues.” Tasting fizz begins with a special protein that’s tethered to sour-sensing taste cells on the tongue, researchers report in the Oct. 16 Science. This protein, the enzyme carbonic anhydrase 4, splits carbon dioxide into bicarbonate ions and free protons, which stimulate the sour-sensing cells. Scientists have long thought that the taste of carbonated beverages emerged from the physical bursting of bubbles on the tongue, says study author Charles Zuker, a neuroscientist now at Columbia University who did the work while at the University of California, San Diego. But bubbly drinks still taste distinctly carbonated when they are imbibed in a pressure chamber where bubbles don’t burst. To understand how carbonation fits into the sensory repertoire, Zuker, Nick Ryba of the National Institute of Dental and Craniofacial Research in Bethesda, Md., and their colleagues measured nerve activity in mouse taste cells. When the rodents were given carbon dioxide in the form of club soda or gaseous CO2, their taste cells responded robustly to CO2. The researchers then genetically engineered mice that were missing one of the five kinds of taste cell—sweet, salty, umami, bitter and sour. Taste-sensing nerves fired in response to carbon dioxide except in the “sourless” mice, pinpointing the role of the sour-sensing taste cells. © Society for Science & the Public 2000 - 2009

Keyword: Chemical Senses (Smell & Taste)
Link ID: 13359 - Posted: 06.24.2010

By Tina Hesman Saey Speech sequenceAn X-ray shows electrodes used to pinpoint the source of epileptic seizures. Researchers also used the electrodes to show that Broca’s area computes the meaning, structure and sound of words in split-second sequences. Ned T. Sahin The brain goes from zero to speech in 600 milliseconds. Scientists have known this fact, but have debated exactly how the brain processes language and then converts the thoughts to speech. Questions have centered on the role of Broca’s area, a language-processing center located on the left side of the brain and first described by the French doctor Pierre Paul Broca in 1865. Since then, researchers have made little progress in understanding the details of how the area helps a person speak, partly because tools such as functional MRI are too slow to measure the activity of single neurons or groups of neurons. Now, patients with epilepsy are giving researchers split-second insight into language processing in Broca’s area. Three people with epilepsy had a rare surgery to implant electrodes in their brains. The surgery allows doctors to pinpoint the source of seizures and treat the condition while sparing parts of the brain that control language, vision and other important processes. The patients gave permission for Ned Sahin of the University of California, San Diego School of Medicine and his colleagues to measure activity in their brains during pre-surgery tests. © Society for Science & the Public 2000 - 2009

Keyword: Language; Epilepsy
Link ID: 13358 - Posted: 06.24.2010

Eric Bland, Discovery News -- An artificial retina could restore sight to the blind, according to new research from the Massachusetts Institute of Technology. The device can be plugged directly into the optic nerve and is based on widely used cochlear implants. "We are skipping the rods and cones in the eye," said Shawn Kelly, a professor at MIT who is developing the artificial retina. "Instead, we are using a camera outside the eye to collect the image, transmitting that image to a chip inside the eye, and using an electric current to directly stimulate the nerves." The artificial retina is designed to help people with advanced macular degeneration or retinitis pigmentosa, progressive diseases that permanently blind patients, usually older patients. Some drugs can delay the process, but once the cells that detect light (rods) and color (cones) die, they are gone. The nerves behind the rods and cones do survive, however. For a patient to see again, something needs to stimulate the nerves. A mild electrical charge, applied using a self-contained, surgically implanted device could stimulate the optical nerves and allow a person to see again. © 2009 Discovery Communications, LLC

Keyword: Vision; Robotics
Link ID: 13357 - Posted: 06.24.2010

by Ewen Callaway AN ATTENTION deficit, rather than an inability to feel emotion, may be what makes psychopathic individuals seem fearless. It's a finding that challenges the common characterisation of such people as cold-blooded predators. "A lot of their problems may be a consequence of something that's almost like a learning difficulty," says Joseph Newman, a psychologist at the University of Wisconsin-Madison who investigated how prisoners with psychopathic personalities react when anticipating pain. Previous experiments have suggested such people may not feel fear, while brain imaging studies have found abnormalities in the amygdala, a region that processes fear and other emotions. This has encouraged the perception that they are "emotionally shallow", Newman says. "People call them cold-blooded predators." But he questioned whether this was the whole story. To tease apart why such people behave the way they do, Newman's team recruited 125 male prisoners convicted of serious crimes and scored them on traits characteristic of a psychopathic personality, including narcissism, impulsivity and callousness. About 20 per cent scored highly enough to be described as psychopathic - a proportion typical for criminals but well above the 1 per cent expected in the general population. The researchers then hooked each prisoner up to a device that measures how strongly they blink - an indication of how afraid they are - and placed a screen in front of them. The subjects were warned that during tasks in which letters flashed on the screen, an electric shock would sometimes follow a red letter, but never a green one. © Copyright Reed Business Information Ltd

Keyword: ADHD; Aggression
Link ID: 13356 - Posted: 06.24.2010

By Nayanah Siva By beaming a laser into the brains of fruit flies, scientists have created new memories from scratch. It's an "amazing piece of work," says neuroscientist Simon Schultz of Imperial College London. The memories are very simple: just the association that a particular stimulus is bad and should be avoided. As a first step to creating this association, neuroscientist Gero Miesenböck of the University of Oxford in the United Kingdom and colleagues studied fruit flies that preferred the odor of either 3-octanol (OCT) or 4-methylcyclohexanol (MCH). Next, the team electrically shocked the flies when one or the other odor was present. Naturally, the flies began to avoid the odor associated with the shock, even if they had preferred that odor in the first place. Miesenböck and colleagues then wanted to see whether they could program the flies to dislike an odor without shocking them first. To do this, they injected an engineered version of ATP--a source of cellular energy--into various neural circuits in the flies' brains. This time, when the flies encountered either OCT or MCH, the researchers flashed laser light into their brains. This released the engineered ATP, which activated neurons that release dopamine, a neurotransmitter believed to create aversive memories in flies. Sure enough, flies exposed to the laser light in the presence of OCT or MCH began to avoid that odor, just as though they had been shocked. © 2009 American Association for the Advancement of Science

Keyword: Learning & Memory
Link ID: 13355 - Posted: 06.24.2010

A VIRTUAL reality system created especially for mice could help to explain how the brain creates maps of its surroundings. When both mice and people navigate, specialised "place" cells in the brain's hippocampus fire. Implanted electrodes that sit next to neurons have in the past detected these signals, which are thought to help the brain build maps of the environment. But researchers have long theorised that activity occurring within place cells, which isn't detected by this type of brain implant, is also key to map-making. The trouble is that recording activity within neurons is a more delicate process, which gets disrupted by the physical movement necessary to trigger place-cell activity. Now David Tank at Princeton University, and colleagues, have overcome this problem using virtual reality. To create rodent VR, the team tweaked an open-source version of the first-person-shooter Quake II. They used the game's underlying physics engine to create a 3D virtual corridor that changes as a harnessed mouse walks atop a floating styrofoam ball. "The mouse is playing a video game," says Tank. The mice treated their VR world like the real one - moving up and down the hallway to receive a reward - but without making head movements, enabling recordings to be made from within neurons (Nature, DOI: 10.1038/nature08499). © Copyright Reed Business Information Ltd

Keyword: Learning & Memory
Link ID: 13354 - Posted: 06.24.2010

The chemical urate, which is known to cause gout, appears to slow the progression of Parkinson's disease, US researchers have concluded. The team found that a study confirmed their previous suspicions about urate, which occurs naturally in the blood. Urate is a potent antioxidant and so counteracts oxygen-related cell damage thought to contribute to Parkinson's, they report in Archives of Neurology. Trials are under way to find a safe way to raise urate levels as a therapy. With support from the Michael J Fox Foundation, the researchers will recruit 90 recently diagnosed Parkinson's patients for treatment with a chemical which helps to produce urate - called inosine - to see if this can raise urate levels so as to slow or halt disease progression. Diets which are rich in foods like liver, seafood and dried beans and peas, as well as alcohol, can also increase blood urate levels. But too much urate in the blood can cause gout, a painful joint disease. Dr Michael Schwarzschild and colleague Dr Alberto Ascherio originally made the link between urate and Parkinson's when analysing data from a previous clinical trial. Their latest work confirms their hunch that urate is protective, they say. They looked at samples of both blood and cerebrospinal fluid - the fluid that surrounds the brain and spinal cord - and measured urate levels. Among the 800 Parkinson's patients in the study there was a clear trend linking higher urate levels and slower disease progression. Dr Schwarzschild, associate professor of neurology at Massachusetts General Hospital in Boston, said: "Urate is a major antioxidant and it can protect brain cells in the lab, which makes this a compelling possibility; but we don't yet know if it's urate itself or some urate-determining factor that helps people with Parkinson's." (C)BBC

Keyword: Parkinsons
Link ID: 13353 - Posted: 10.13.2009

by Anil Ananthaswamy THE young man woke feeling dizzy. He got up and turned around, only to see himself still lying in bed. He shouted at his sleeping body, shook it, and jumped on it. The next thing he knew he was lying down again, but now seeing himself standing by the bed and shaking his sleeping body. Stricken with fear, he jumped out of the window. His room was on the third floor. He was found later, badly injured. What this 21-year-old had just experienced was an out-of-body experience, one of the most peculiar states of consciousness. It was probably triggered by his epilepsy (Journal of Neurology, Neurosurgery and Psychiatry, vol 57, p 838). "He didn't want to commit suicide," says Peter Brugger, the young man's neuropsychologist at University Hospital Zurich in Switzerland. "He jumped to find a match between body and self. He must have been having a seizure." In the 15 years since that dramatic incident, Brugger and others have come a long way towards understanding out-of-body experiences. They have narrowed down the cause to malfunctions in a specific brain area and are now working out how these lead to the almost supernatural experience of leaving your own body and observing it from afar. They are also using out-of-body experiences to tackle a long-standing problem: how we create and maintain a sense of self. Dramatised to great effect by such authors as Dostoevsky, Wilde, de Maupassant and Poe - some of whom wrote from first-hand knowledge - out-of-body experiences are usually associated with epilepsy, migraines, strokes, brain tumours, drug use and even near-death experiences. It is clear, though, that people with no obvious neurological disorders can have an out-of-body experience. By some estimates, about 5 per cent of healthy people have one at some point in their lives. © Copyright Reed Business Information Ltd

Keyword: Miscellaneous
Link ID: 13352 - Posted: 06.24.2010

By Katherine Harmon Chinese dyslexia may be much more complex than the English variety, according to a new paper published online today in Current Biology. English speakers who have developmental dyslexia usually don't have trouble recognizing letters visually, but rather just have a hard time connecting them to their sounds. What about languages based on full-word characters rather than sound-carrying letters? Researchers looking at the brains of dyslexic Chinese children have discovered that the disorder in that language often stems from two separate, independent problems: sound and visual perception. The pronunciation of detailed and complex Chinese characters must be memorized, rather than sounded out like words in alphabet-based languages. That requirement led researchers to suspect that disabilities in the visual realm might come into play in dyslexia in that language. "A fine-grained visuospatial analysis must be preformed by the visual system in order to activate the characters' phonological and semantic information," said lead author Wai Ting Siok of the University of Hong Kong, in a prepared statement. To see whether Chinese dyslexics had trouble comprehending visual details, researchers used functional magnetic resonance imaging (fMRI) to study the brains of 12 Chinese children with dyslexia. When asked to complete a task that involved visually judging size, the dyslexic children had less activation in an area of the brain that is charged with visual-spatial processing (the left intraparietal sulcus) than did Chinese children with normal reading levels. Previous research had also shown that the dyslexic group had weak activation in areas that process phonological information (the left middle frontal gyrus) when tested with a rhyming task. © 1996-2009 Scientific American Inc.

Keyword: Dyslexia
Link ID: 13351 - Posted: 06.24.2010

By NATALIE ANGIER Imagine what a dinner conversation would be like if you had decent table manners, but the ears of a lizard. Not only would you have to stop eating whenever you wanted to speak, but, because parts of your ears are now attached to your jaw, you’d have to stop eating whenever you wanted to hear anybody else, as well. With no fork action on your end, your waiter would soon conclude that you were obviously “done working on that” and would whisk your unbreached baked ziti away. Sometimes it’s the little things in life that make all the difference — in this case, the three littlest bones of the human body. Tucked in our auditory canal, just on the inner side of the eardrum, are the musically named malleus, incus and stapes, each minibone, each ossicle, about the size of a small freshwater pearl and jointly the basis of one of evolution’s greatest inventions, the mammalian middle ear. The middle ear gives us our sound bite, our capacity to masticate without being forced to turn a momentarily deaf ear to the world, as most other vertebrates are. Who can say whether we humans would have become so voraciously verbal if not for the practice our ancestors had of jawboning around the wildebeest spit. The middle ear also explains why mammals, as a group, have the sharpest hearing on Earth and the greatest diversity of listening styles, from the bats and dolphins that can detect pressure waves bouncing around at the spiky, ultrasonic end of the bandwidth, to elephants and humpbacked whales that can hear infrasonically, capturing the long, low sound prints muttered by their peers for miles around. All told, a new study suggests, the middle ear was such a great invention, such an essential part of being a mammal, that once evolution had seized upon it, no crude substitute or older model would do. Copyright 2009 The New York Times Company

Keyword: Hearing; Evolution
Link ID: 13350 - Posted: 06.24.2010

By Chadrick Lane My mother is a more patient human being after having raised a child who incessantly asked, “Are we there yet?” That information, often out of reach for a frustrated toddler, carries with it a feeling of reward. The majority of us are all too familiar with the urge to know more about the future, whether it is an exam grade, an experimental result, or the status of a new job. Prior knowledge frequently has no effect on the actual outcome of the event – we’ll get the same grade regardless – and yet we still desperately want to know. This leads to what scientists refer to as “information-seeking behavior” – our mind craves relevant information. The neural basis behind this seemingly universal desire has eluded scientists for some time, but the wait is over. Contemporary theories of reinforcement learning are rooted in the dopaminergic reward system. Dopamine neurons in parts of the midbrain, such as the ventral tegmental area and substantia nigra pars compacta, play a vital role in the expectation of reward. Most of what is known about these neurons comes from electrode recording experiments with rhesus monkeys. Not surprisingly, these neurons respond to primitive rewards, such as food and water. They signal a monkey’s expectation of rewards, but what was not known until now is whether these same neurons might also signal expectation of information. To test for this preference for information, which is a cognitive reward, a new paradigm needed to be put in place. Ethan Bromberg-Martin and Okihide Hikosaka, both at the National Eye Institute, developed a brilliant behavioral task that opened the door. © 1996-2009 Scientific American Inc.

Keyword: Drug Abuse
Link ID: 13349 - Posted: 06.24.2010

Children can be taught to use their imagination to tackle frequent bouts of stomach pain, research shows. A relaxation-type CD, asking children to imagine themselves in scenarios like floating on a cloud led to dramatic improvements in abdominal pain. The US researchers said the technique worked particularly well in children as they have such fertile imaginations. It has been estimated that frequent stomach pain with no identifiable cause affects up to one in five children. The research, published in the journal Pediatrics, follows on from studies showing hypnosis is an effective treatment for a range of conditions known as functional abdominal pain, which includes things like irritable bowel syndrome. In this study, the children had 20 minute sessions of "guided imagery" - a technique which prompts the subject to imagine things which will reduce their discomfort. One example is letting a special shiny object melt into their hand and then placing their hand on their belly, spreading warmth and light from the hand inside the tummy to make a protective barrier inside that prevents anything from irritating the belly. The researchers, from the University of North Carolina and Duke University Medical Center, said a lack of therapists led them to the idea of using a CD to deliver the sessions. In all 30 children aged between six and 15 years took part in the study - half of whom used the CDs daily for eight weeks and the rest of whom got normal treatment. Among those who had used the CDs, 73.3% reported that their abdominal pain was reduced by half or more by the end of the treatment course compared with 26.7% in the standard care group. In two-thirds of children the improvements were still apparent six months later. (C)BBC

Keyword: Pain & Touch
Link ID: 13348 - Posted: 10.12.2009

by Jessica Hamzelou Juggling boosts the connections between different parts of the brain by tweaking the architecture of the brain's "white matter" – a finding that could lead to new therapies for people with brain injuries. White matter describes all areas of the brain that contain mostly axons – outgrowths of nerve cells that connect different cells. It might be expected that learning a new, complex task such as juggling should strengthen these connections, but previous work looking for changes in the brains of people who had learned how to juggle had only studied increases in grey matter, which contains the nerve cells' bodies. Now Jan Scholz and his colleagues at the University of Oxford have discovered that juggling changes white matter, too. They gave 24 young men and women training packs for juggling and had them practise for half an hour a day for six weeks. Before and after this training period, the researchers scanned the brains of the jugglers along with those of 24 people who didn't do any juggling, using a technique called diffusion tensor imaging that reveals the structure of white matter. They found that there was no change in the brains of the non-jugglers, but the jugglers grew more white matter in a part of the parietal lobe – an area involved in connecting what we see to how we move. The same transformation was seen in all the jugglers, regardless of how well they could perform. This suggests that it's the learning process itself that is important for brain development, not how good you are. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 13347 - Posted: 06.24.2010

by Henry Nicholls IN 2003, while geneticist Svante Pääbo was visiting Novosibirsk, Russia's third-largest city, he decided to look in on a famous experiment run by the Institute of Cytology and Genetics, which is based in the city. Fifty years ago, the then head of the IC&G, geneticist Dmitry Belyaev, had begun breeding silver foxes to see how easily they could be tamed. What Pääbo didn't know, though, is that Belyaev had also set up another experiment in the 1970s involving rats. This time, one line of rats was selected for tameness and another selected for aggression. When Pääbo saw them, he was stunned. After just 30 years of selection, the IC&G researchers had fashioned two populations that could hardly be more different. "I could take the tame ones out of the cage with my bare hands. They would creep under my shirt and seemed to actually seek and enjoy contact," recalls Pääbo. "The aggressive animals were so aggressive I got the feeling that 10 or 20 of them would probably kill me if they got out of the cages." The aggressive rats were so aggressive I got the feeling that 10 or 20 of them would kill me if they got out of the cage Here was a great opportunity to uncover the genetic changes responsible for the behavioural differences, Pääbo realised. Back at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, Pääbo and his team have been trying to do just this. If they succeed, their findings could have far-reaching consequences. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 13346 - Posted: 06.24.2010

By Emily Anthes In his speech to America’s schoolchildren last month, President Obama had a clear directive about video games: Put them away. It wasn’t the first time he had sounded this particular alarm, warning of the dangers of days spent at gaming consoles. But the latest science shows that there’s a lot more to video games than their dark reputations suggest. “There’s still a tendency to think of video games as a big wad of time-wasting content,’’ said Cheryl Olson, co-director of the Center for Mental Health and Media at Massachusetts General Hospital. “You would never hear a parent say we don’t allow books in our home, but you’ll still hear parents say we don’t allow video games in our home. “Games are a medium. They’re not inherently good or bad.’’ After years of focusing on the bad - and there are still legitimate concerns, for instance, about the psychological effects of certain violent games - scientists are increasingly examining the potential benefits of video games. Their studies are revealing that a wide variety of games can boost mental function, improving everything from vision to memory. Still unclear is whether these gains are long-lasting and can be applied to non-game tasks. But video games, it seems, might actually be good for the brain. The very structure of video games makes them ideal tools for brain training. © 2009 NY Times Co.

Keyword: Learning & Memory
Link ID: 13345 - Posted: 06.24.2010

By Tina Hesman Saey For many people, days just don’t seem long enough. In order to cram everything into one 24-hour period, something has to give. Judging by many surveys of Americans, it’s sleep. Sleep is regarded by some as unproductive, wasteful downtime. People who would rather hit the hay than the dance floor are told that only losers snooze and that they can sleep when they’re dead. But new data about sleep’s benefits suggest that losing sleep might speed up death’s arrival. Recent research also shows that people who don’t snooze enough face a higher risk of losing their health than those who regularly get a good night’s sleep. “What is certain is that we can’t do without sleep,” says Peter Meerlo, a neuroscientist at the University of Groningen in the Netherlands. Some of the consequences of lost sleep are immediate, obvious and unpleasant, such as a toddler’s crabbiness after missing a nap. Older children and adults get irritable when tired, too. Sleepy students don’t learn or perform as well as their well-rested peers (SN: 09/09/06, p. 174). And nodding off at work probably won’t help anyone get a promotion. Other penalties for staying up too late can be far more serious, even deadly. Studies have linked chronic sleep loss to obesity (SN: 11/17/07, p. 318; SN: 4/1/06, p. 195), heart disease, high blood pressure, diabetes (SN: 1/3/09, p. 5; SN: 1/19/08, p. 46) and shorter lives (SN: 2/8/03, p. 85) in people and laboratory animals. And now, a new study links sleep loss in mice to Alzheimer’s disease plaques (SN: 10/24/09, p. 11). And some evidence suggests that stinting on sleep night after night may cause long-term — maybe even permanent — changes in the brain, some of which may predispose people to mental disorders such as depression. © Society for Science & the Public 2000 - 2009

Keyword: Sleep; Neuroimmunology
Link ID: 13344 - Posted: 06.24.2010

By Laura Sanders If Ben Franklin had been able to live by his own advice, he might have been even healthier, wealthier and wiser. But he was a notorious insomniac, rumored to have been such a poor sleeper that he required two beds so he could always crawl into one with cool sheets when he couldn’t sleep. Getting a good night’s sleep turned out to be more difficult than taming lightning, heating houses or designing bifocal specs. Today millions of people afflicted by sleep disorders know how Franklin felt. Some people can’t fall asleep even when they’re exhausted. Yet other people fall asleep when they should be wide awake. Although sleep disorders take many different forms, they do have one thing in common: The more researchers learn, the more they have left to figure out. Sleep problems present a constellation of symptoms, trigger overlapping diagnoses and divulge no clear causes. “We always feel like we’re one step away from getting all of the answers,” says Adi Aran of Stanford University, “but I really believe that in the next decade we will understand much more about sleep disorders.” Already, some recent advances have brought scientists closer to discerning the ultimate causes of such disorders, even suggesting possible treatments. Masashi Yanagisawa of the University of Texas Southwestern Medical Center at Dallas believes researchers are poised to “crack open the black box of sleep regulation.” © Society for Science & the Public 2000 - 2009

Keyword: Sleep; Narcolepsy
Link ID: 13343 - Posted: 06.24.2010

By Tina Hesman Saey In a lab at MIT, a small black mouse named Buddy sleeps alone inside a box. A cone resembling a satellite dish sits atop his head. But the dish doesn’t receive signals from outer space. Instead it sends transmissions from deep inside Buddy’s brain to a bank of computers across the room. Scientists like Jennie Young eavesdrop on the transmissions, essentially reading Buddy’s mind, or at least that part of his mind occupied with a recent trip along a Plexiglas track littered with chocolate sprinkles. Young and her colleagues in Susumu Tonegawa’s laboratory are monitoring nerve cells inside the hippocampus, one of the brain’s most important learning and memory centers. Some of the cells in the sea horse–shaped hippocampus fired bursts of electrical energy as Buddy moved along the track. As he sleeps in his black box, those same cells spark to life again, replaying progress along the track in fast-forward or rapid reverse. By recording the slumbering Buddy’s brain cell activity, the scientists hope to glean clues to one of biology’s greatest mysteries: the reason for sleep. Although sleep is among the most basic of behaviors, its function has proved elusive. Scientists say sleep’s job is to save energy, or to build up substances needed during waking or to tear down unneeded connections between brain cells. Some emphasize sleep’s special role in learning and memory. Others suggest that sleep regulates emotions. Or strengthens the immune system. And some scientists believe sleep is simply something that emerges naturally from having networks of neurons wired together. © Society for Science & the Public 2000 - 2009

Keyword: Sleep; Learning & Memory
Link ID: 13342 - Posted: 06.24.2010