By Frances Stead Sellers Carolyn McCaskill remembers exactly when she discovered that she couldn’t understand white people. It was 1968, she was 15 years old, and she and nine other deaf black students had just enrolled in an integrated school for the deaf in Talledega, Ala. When the teacher got up to address the class, McCaskill was lost. “I was dumbfounded,” McCaskill recalls through an interpreter. “I was like, ‘What in the world is going on?’ ” The teacher’s quicksilver hand movements looked little like the sign language McCaskill had grown up using at home with her two deaf siblings and had practiced at the Alabama School for the Negro Deaf and Blind, just a few miles away. It wasn’t a simple matter of people at the new school using unfamiliar vocabularly; they made hand movements for everyday words that looked foreign to McCaskill and her fellow black students. So, McCaskill says, “I put my signs aside.” She learned entirely new signs for such common nouns as “shoe” and “school.” She began to communicate words such as “why” and “don’t know” with one hand instead of two as she and her black friends had always done. She copied the white students who lowered their hands to make the signs for “what for” and “know” closer to their chins than to their foreheads. And she imitated the way white students mouthed words at the same time as they made manual signs for them. Whenever she went home, McCaskill carefully switched back to her old way of communicating. © 1996-2012 The Washington Post

Keyword: Language
Link ID: 17271 - Posted: 09.18.2012

By HARRIET BROWN A few years ago, Mercedes Carnethon, a diabetes researcher at the Feinberg School of Medicine at Northwestern University, found herself pondering a conundrum. Obesity is the primary risk factor for Type 2 diabetes, yet sizable numbers of normal-weight people also develop the disease. Why? In research conducted to answer that question, Dr. Carnethon discovered something even more puzzling: Diabetes patients of normal weight are twice as likely to die as those who are overweight or obese. That finding makes diabetes the latest example of a medical phenomenon that mystifies scientists. They call it the obesity paradox. In study after study, overweight and moderately obese patients with certain chronic diseases often live longer and fare better than normal-weight patients with the same ailments. The accumulation of evidence is inspiring some experts to re-examine long-held assumptions about the association between body fat and disease. Dr. Carl Lavie, medical director of cardiac rehabilitation and prevention at the John Ochsner Heart and Vascular Institute in New Orleans, was one of the first researchers to document the obesity paradox, among patients with heart failure in 2002. He spent more than a year trying to get a journal to publish his findings. “People thought there was something wrong with the data,” he recalled. “They said, ‘If obesity is bad for heart disease, how could this possibly be true?’ ” But there were hints everywhere. One study found that heavier dialysis patients had a lower chance of dying than those whose were of normal weight or underweight. Overweight patients with coronary disease fared better than those who were thinner in another study; mild to severe obesity posed no additional mortality risks. © 2012 The New York Times Company

Keyword: Obesity
Link ID: 17270 - Posted: 09.18.2012

By MyHealthNewsDaily staff In common weight-loss advice, "get more sleep," should figure just as prominently as "eat less" and "move more," two researchers in Canada argue. There is strong evidence that lack of sleep is contributing to the obesity epidemic, they said, and factors that contribute to obesity that have been given less attention than diet and exercise may at least partly explain why weight-loss efforts fail, according to the researchers. "Among the behavioural factors that have been shown to impede weight loss, insufficient sleep is gaining attention and recognition," the researchers write in their editorial published today (Sept. 17) in the Canadian Medical Association Journal. The researchers pointed to a 2010 study in which participants were randomly assigned to sleep either 5.5 hours or 8.5 hours every night for 14 days. They all cut their daily calorie intake by 680 calories, and slept in a lab. Participants who slept for 5.5 hours lost 55 percent less body fat, and 60 percent more of their lean body mass than those who slept for longer. In other words, the sleep-deprived people held onto their fat tissue, and instead lost muscle. In another study, published in July, researchers looked at 245 women in a six-month weight loss program and found that those who slept more than seven hours a night, and those who reported better quality sleep, were 33 percent more likely to succeed in their weight-loss efforts. © 2012 NBCNews.com

Keyword: Obesity; Sleep
Link ID: 17269 - Posted: 09.18.2012

By Scicurious It’s often interesting to look over the scientific literature, and to see, for lack of a better term, “fashion trends”. Not what style of kahkis the PIs are wearing this fall, but rather neurotransmitters, techniques, behaviors, or models that you can watch go in and out of fashion. There are lots of different reasons for why this occurs, sometimes a new, better model comes along, sometimes the technique is not a versatile as first thought, sometimes the new neurotransmitter field gets extremely “crowded” and people feel they need to branch out. But it’s interesting to see things wax and wane, and to try and see if you can predict where some things are going. For example, when it first appeared on the scene, the technique of optogenetics (stimulating cells to fire by hitting them with light, because you have infected them with a light sensitive channel) was the new hot thing. Optogenetics is still very “now”, and promises to stick around for a bit, as the flexibility of the technique is still being tested. Knockout mice, on the other hand, though they were wildly popular (and are still), are being replaced with things like targeted knockouts of genes that are localized to specific regions, or inducible knockouts that will only become knockouts when you stimulate the system with something in the diet. It’s a more specific technique and so the older technique is gradually becoming less popular. It works the same way for neurotransmitters, the chemicals released between neurons to convey messages. And I’ve been noticing a new one that I think is going to be an up and comer. This chemical is called orexin (or hypocretin, two groups characterized it at the same time and the name war has continued for years now. It looks like orexin is winning out, for while hypocretin is more functionally accurate…orexin sounds a lot better and is easier to say). Orexin was originally noticed due to two main behaviors: sleep, and appetite. Orexin is a powerful mediator of something called arousal (what you might also call attention or wakefulness, though it’s not quite the same as either). In fact, the most common form of narcolepsy is due to a lack of orexin in the brain. © 2012 Scientific American

Keyword: Obesity; Anorexia & Bulimia
Link ID: 17268 - Posted: 09.18.2012

by Michael Marshall The human brain may be the most complex object in the universe, but its construction mostly depends on one thing: the shape of neurons. Different kinds of neuron are selective about which other neurons they connect to and where they attach. Specific signalling chemicals are thought to be vital in guiding this process. Henry Markram of the Swiss Federal Institute of Technology in Lausanne and colleagues built 3D computer models of the rat somatosensory cortex, each containing a random mix of cell types found in rat brains, but no signalling chemicals. Nevertheless, 74 per cent of the connections ended up in the correct place, merely by allowing the cells to develop into their normal shape. The results suggest that much of the brain could be mapped without incorporating signalling chemicals. This is good news for neuroscientists struggling to map the brain's dizzying web of connections. "It would otherwise take decades to map each synapse in the brain," says Markram. The work could also help untangle the causes of conditions like schizophrenia that are thought to be caused by flaws in brain wiring. If Markram's work proves correct, malformed neurons that don't connect up properly could be a factor. Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1202128109 © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain
Link ID: 17267 - Posted: 09.18.2012

By Melinda Wenner Moyer Read any Web forum, and you'll agree: people are meaner online than in “real life.” Psychologists have largely blamed this disinhibition on anonymity and invisibility: when you're online, no one knows who you are or what you look like. A new study in Computers in Human Behavior, however, suggests that above and beyond anything else, we're nasty on the Internet because we don't make eye contact with our compatriots. Researchers at the University of Haifa in Israel asked 71 pairs of college students who did not know one another to debate an issue over Instant Messenger and try to come up with an agreeable solution. The pairs, seated in different rooms, chatted in various conditions: some were asked to share personal, identifying details; others could see side views of their partner's body through webcams; and others were asked to maintain near-constant eye contact with the aid of close-up cameras attached to the top of their computer. Far more than anonymity or invisibility, whether or not the subjects had to look into their partner's eyes predicted how mean they were. When their eyes were hidden, participants were twice as likely to be hostile. Even if the subjects were both unrecognizable (with only their eyes on screen) and anonymous, they rarely made threats if they maintained eye contact. Although no one knows exactly why eye contact is so crucial, lead author and behavioral scientist Noam Lapidot-Lefler, now at the Max Stern Yezreel Valley College in Israel, notes that seeing a partner's eyes “helps you understand the other person's feelings, the signals that the person is trying to send you,” which fosters empathy and communication. © 2012 Scientific American,

Keyword: Aggression; Emotions
Link ID: 17266 - Posted: 09.17.2012

Nicky Guttridge Subtle differences in the DNA of honeybees are reflected in the bees' roles within the hive. These DNA modifications are normally fixed, but research published today in Nature Neuroscience1 reveals the first example of reversible changes to DNA associated with behaviour. All honeybees (Apis mellifera) are born equal, but this situation doesn’t last long. Although genetically identical, the bees soon take on the specific roles of queen or worker. These roles are defined not just by behavioural differences, but by physical ones. Underlying them are minor modifications to their DNA: ‘epigenetic’ changes that leave the DNA sequence intact, but that add chemical tags in the form of methyl (CH3) molecules to sections of the DNA. This in turn alters the way a gene is expressed2. Once a bee is a queen or worker, they fulfil that role for life — the change is irreversible. But that is not the case for the subdivisions among the workers. The workers start out as nurses, which look after and feed the queen and larvae, and most then go on to become foragers, which travel out from the hive in search of pollen. Again the two types have very different methylation patterns in their DNA. This time, however, as the latest results show, the DNA modifications are reversible: if a forager reverts to being a nurse, its methylation pattern reverts too. © 2012 Nature Publishing Group

Keyword: Genes & Behavior; Epigenetics
Link ID: 17265 - Posted: 09.17.2012

By Jorge Cham and Dwayne Godwin [Graphic novel format.] Dwayne Godwin is a neuroscientist at the Wake Forest University School of Medicine. Jorge Cham draws the comic strip Piled Higher and Deeper at www.phdcomics.com. © 2012 Scientific American,

Keyword: Pain & Touch
Link ID: 17264 - Posted: 09.17.2012

By James Gallagher Health and science reporter, BBC News Having a highly demanding job, but little control over it, could be a deadly combination, UK researchers say. They analysed 13 existing European studies covering nearly 200,000 people and found "job strain" was linked to a 23% increased risk of heart attacks and deaths from coronary heart disease. The risk to the heart was much smaller than for smoking or not exercising, the Lancet medical journal report said. The British Heart Foundation said how people reacted to work stress was key. Job strain is a type of stress. The research team at University College London said working in any profession could lead to strain, but it was more common in lower skilled workers. Doctors who have a lot of decision-making in their jobs would be less likely to have job strain than someone working on a busy factory production line. Freedom There has previously been conflicting evidence on the effect of job strain on the heart. In this paper, the researchers analysed combined data from 13 studies. At the beginning of each of the studies, people were asked whether they had excessive workloads or insufficient time to do their job as well as questions around how much freedom they had to make decisions. BBC © 2012

Keyword: Stress
Link ID: 17263 - Posted: 09.17.2012

By BENEDICT CAREY Scientists have designed a brain implant that sharpened decision making and restored lost mental capacity in monkeys, providing the first demonstration in primates of the sort of brain prosthesis that could eventually help people with damage from dementia, strokes or other brain injuries. The device, though years away from commercial development, gives researchers a model for how to support and enhance fairly advanced mental skills in the frontal cortex of the brain, the seat of thinking and planning. The new report appeared Thursday in The Journal of Neural Engineering. In just the past decade, scientists have developed brain implants that improve vision or allow disabled people to use their thoughts to control prosthetic limbs or move computer cursors. The new paper, led by researchers at Wake Forest Baptist Medical Center and the University of Southern California, describes a device that improves brain function internally, by fine-tuning communication among neurons. Previous studies have shown that a neural implant can do this for memory in rodents, but the new report extends that work significantly, experts said — into brains that are much closer to those of humans. In the study, researchers at Wake Forest trained five rhesus monkeys to play a picture-matching game. The monkeys saw an image on a large screen — of a toy, a person, a mountain range — and tried to select the same image from a larger group of images that appeared on the same screen a little while later. The monkeys got a treat for every correct answer. After two years of practice, the animals developed some mastery, getting about 75 percent of the easier matches correct and 40 percent of the harder ones, markedly better than chance guessing. © 2012 The New York Times Company

Keyword: Learning & Memory; Robotics
Link ID: 17262 - Posted: 09.15.2012

By Susan Milius Male killer whale thirtysomethings appear to live longer when mom’s nearby, especially if mom has stopped reproducing. This survival bonus for mama’s boys could be the first evidence from nonhuman animals for an evolutionary advantage to living long after reproduction stops. In the Pacific Northwest, a male killer whale’s risk of disappearing, presumably from dying, seems to jump almost 14-fold if he’s older than 30 and his post-reproductive mom dies, says marine biologist Emma Foster of the University of Exeter in England. Daughters get a more modest fivefold boost, Foster and her colleagues report in the Sept. 14 Science. Both sons and daughters typically spend their lives swimming with mom and other maternal relatives. Even though a female killer whale may stop having babies in her 30s or 40s, she can live into her 90s. Males typically don’t live as long, but they can keep siring offspring throughout their lives. Keeping sons alive as long as possible should therefore maximize the chances that the mom’s genes will be carried into further generations. So, Foster says, the whale survival boost may help explain how female killer whales have evolved the longest post-reproductive life span known among nonhuman animals. “Menopause is still one of the great mysteries of biology,” Foster says. Evolution works as genes for traits multiply through greater numbers of offspring, so what drives the evolution of a no-babies phase of adulthood has been a puzzle. Some theorists have argued that this post-reproductive life span is just a side effect of other survival-boosting traits, but other biologists have searched for some benefit in staying alive post-baby-bearing. The evidence is “quite heavily debated,” as Foster puts it. © Society for Science & the Public 2000 - 2012

Keyword: Sexual Behavior; Evolution
Link ID: 17261 - Posted: 09.15.2012

Sandrine Ceurstemont, editor, New Scientist TV It's not yet possible to make Silvio Berlusconi disappear, but now a new illusion can shrink his head. Created by Tim Meese and colleagues at Aston University in Birmingham, UK, the animation tricks our brain with moving circles of different sizes before presenting the mind-altering images of his face. To perceive the effect, fix your eyes on the cross in the center of the video. Once the motion stops and the head pictures are flashed on-screen, the image on the left should appear smaller than the one on the right. If you pause the video, you'll notice that in fact both heads are the same size. According to Daniel Baker, a member of the team, the trick occurs because our brain adapts to the size of the moving circles, tiring out the mechanisms that respond to those sizes. So after viewing the large circle on the left, the head presented in its place looks smaller and vice versa. The same type of effect can also alter an object's orientation after staring at tilted patterns. The team was surprised to find that the illusion takes place with any image, regardless of the pattern it's filled in with. "It's rare for an effect to be so general," says Baker. "You could adapt to pictures of kittens and it would still work." © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 17260 - Posted: 09.15.2012

By Laura Sanders Changes in the brains of mice that were isolated as young pups may help explain the profound behavioral problems of severely neglected children. The mouse experiments suggest that neglect during a specific developmental window irreversibly stunts brain development, researchers report in the Sept. 14 Science. Over the last decade, researchers have catalogued brain deficits and behavioral problems in Romanian orphans who were raised in bare-bones environments with little social stimulation. Many of these children display hyperactivity, impulsivity and compulsive behavior such as arm flapping. Although superficially friendly, these kids have trouble forming meaningful relationships. By studying mice that had been isolated early in life, researchers led by Gabriel Corfas of Children’s Hospital Boston and Harvard Medical School hoped to uncover how social deprivation can affect the developing brain. After the mice had weaned, the researchers put them into one of three environments: One was a deluxe suite, enriched with fresh toys every other day and populated by friends of similar ages, one was a standard laboratory cage holding four mice, and one was a holding cell for total isolation. After two weeks, mice in the deluxe suite and the regular cage showed no abnormalities in their behavior or brains. But mice that were isolated showed big changes. These animals were socially stunted, showing less signs of exploratory behavior and a diminished working memory. What’s more, the researchers uncovered stunted development in the brain’s white matter, which helps nerve cells communicate. © Society for Science & the Public 2000 - 2012

Keyword: Stress; Glia
Link ID: 17259 - Posted: 09.15.2012

By Judy Stone In one sense, it is refreshing to see men being the target of pharma, after all these years of women being the focus of relentless—and misleading—advertising. On the other, we’re seeing the start of yet another pharma campaign to dupe the public by the unnecessary medicalization of symptoms to create new drug markets. I used to be a fairly enthusiastic pharma fan, but over recent years have become increasingly disillusioned. The hype over testosterone is the latest example of why. With so many pressing problems in the world, I wish pharma would focus their attention on doing something more useful with their energies. I thought it started with drugs for “hot flashes,” but Karen Roush set me straight about hormone therapy, reporting that “It all started with men in ancient civilizations eating the penis and testicles of animals as a cure for impotence.” (And to think that Maryn McKenna just warned us of the dangers of kissing cats! This early hormone therapy sounds a bit dicier.) In the 1940s, estrogen was able to be extracted from horse urine in large quantities, enabling a supply for treating women “suffering from estrogen deficiency.” Dr. Robert Wilson, a prominent New York gynecologist, founded a private trust in 1963 to promote estrogen use. Pharmaceutical companies provided $1.3 million to this “trust;” they, of course, stood to profit handsomely from their investment in Wilson’s endeavor. Wilson is described as being “evangelical” in his crusade to save women from the “decay” of menopause. He was quite successful, with his 1966 book, Feminine Forever, selling 100,000 copies in the first seven months alone. His theme, “A Plea for the Maintenance of Adequate Estrogen from Puberty to Grave,” expounded in a mainstream medical journal, was adopted both by the medical profession and by the popular press. © 2012 Scientific American

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 17258 - Posted: 09.15.2012

Excerpted from The Chemistry Between Us: Love, Sex and the Science of Attraction, by Larry Young, PhD, and Brian Alexander, by arrangement with Current, a member of Penguin Group (USA), Inc., Copyright © Larry J. Young and Brian Alexander, 2012. To investigate the rodent version of getting hugs, and what happens in the absence of hugs from a bonded partner, Bosch took virgin males and set them up in vole apartments with roommates—either a brother they hadn't seen in a long time or an unfamiliar virgin female. As males and females are wont to do, the boy-girl roommates mated and formed a bond. After five days, he split up half the brother pairs, and half the male-female pairs, creating what amounted to involuntary vole divorce. Then he put the voles through a series of behavioral tests. The first is called the forced-swim test. Bosch likens it to an old Bavarian proverb about two mice who fall into a bucket of milk. One mouse does nothing and drowns. The other tries to swim so furiously the milk turns into butter and the mouse escapes. Paddling is typically what rodents will do if they find themselves in water; they'll swim like crazy because they think they'll drown if they don't. (Actually, they'll float but apparently no rodent floaters have ever returned to fill in the rest of the tribe.) The voles that were separated from their brothers paddled manically. So did the voles who stayed with their brothers and the voles who stayed with their female mates. Only the males who'd gone through vole divorce floated listlessly as if they didn't care whether they drowned. "It was amazing," Bosch recalls. "For minutes, they would just float. You can watch the video and without knowing which group they were in, you can easily tell if it's an animal separated from their partner, or still with their partner." Watching the videos of them bob limply, it's easy to imagine them moaning out "Ain't No Sunshine When She's Gone" with their tiny vole voices. © 2012 Scientific American,

Keyword: Sexual Behavior
Link ID: 17257 - Posted: 09.15.2012

Drivers who take certain antidepressants, anti-anxiety or sleeping pills could be at higher risk for motor vehicle collisions. Psychotropic drugs can impair a driver's ability to control a vehicle, but there's been less research on newer drugs used to treat insomnia. To learn more, researchers in Taiwan compared drug use among 5,183 people involved in motor vehicle accidents with a second group of 31,093 people of the same age and gender who went for outpatient care between 2000 and 2009. In Thursday's issue of the British Journal of Clinical Pharmacology, they concluded that those taking two types of antidepressants, sleep aids known as Z-drugs, and benzodiazepines used to treat anxiety and insomnia, face increased risk of motor vehicle accidents compared with people not taking those types of drugs. The antidepressants studied included selective serotonin re-uptake inhibitors or SSRIs like paroxitine or Paxil and fluoxetine or Prozac and tricyclic or TCA antidepressants such as amiptriptyline. "The findings underscore that subjects taking these psychotropic medications should pay increased attention to their driving performance in order to prevent …motor vehicle accidents," lead researcher Hui-Ju Tsai, of the National Health Research Institutes in Zhunan, Taiwan, and co-authors concluded. © CBC 2012

Keyword: Sleep; Attention
Link ID: 17256 - Posted: 09.13.2012

by Douglas Heaven The versatile cannabis plant may have a new use: it could be used to control epileptic seizures with fewer side effects than currently prescribed anti-convulsants. Ben Whalley at the University of Reading, UK, and colleagues worked with GW Pharmaceuticals in Wiltshire, UK, to investigate the anti-convulsant properties of cannabidivarin (CBDV), a little-studied chemical found in cannabis and some other plants. There is "big, historical, anecdotal evidence" that cannabinoids can be used to control human seizures, says Whalley, but the "side-effect baggage" means there have been relatively few studies of its pharmaceutical effect on this condition. The team investigated the effectiveness of CBDV – one of around 100 non-psychoactive cannabinoids found in cannabis – as an anti-convulsant. They induced seizures in live rats and mice that had been given the drug. These animals experienced less severe seizures and lower mortality compared with animals given a placebo. The drug also had fewer side effects and was better tolerated than three of the most widely prescribed anticonvulsants. Epileptic seizures affect about one per cent of the population. Left uncontrolled, they can lead to depression, cognitive decline and death. If you control the seizures, says Whalley, "the chances of death drop away completely". The decision about whether to test the drug in humans will be made next year. © Copyright Reed Business Information Ltd

Keyword: Epilepsy; Drug Abuse
Link ID: 17255 - Posted: 09.13.2012

The U.S. national campaign to reduce the risk of sudden infant death syndrome has entered a new phase and will now encompass all sleep-related, sudden unexpected infant deaths, officials of the National Institutes of Health announced today. The campaign, which has been known as the Back to Sleep Campaign, has been renamed the Safe to Sleep Campaign. The NIH-led Back to Sleep Campaign began in 1994, to educate parents, caregivers, and health care providers about ways to reduce the risk of sudden infant death syndrome (SIDS). The campaign name was derived from the recommendation to place healthy infants on their backs to sleep, a practice proven to reduce SIDS risk. SIDS is the sudden death of an infant under 1 year of age that cannot be explained, even after a complete death scene investigation, autopsy, and review of the infant's health history. Sudden unexpected infant death (SUID) includes all unexpected infant deaths: those due to SIDS, and as well as those from other causes. Many SUID cases are due to such causes as accidental suffocation and entrapment, such as when an infant gets trapped between a mattress and a wall, or when bedding material presses on or wraps around an infant’s neck. In addition to stressing the placement of infants on their backs for all sleep times, the Safe to Sleep Campaign emphasizes other ways to provide a safe sleep environment for infants. This includes placing infants to sleep in their own safe sleep environment and not on an adult bed, without any soft bedding such as blankets or quilts. Safe to Sleep also emphasizes breast feeding infants when possible, which has been associated with reduced SIDS risk, and eliminating such risks to infant health as overheating, exposure to tobacco smoke, and a mother’s use of alcohol and illicit drugs.

Keyword: Sleep
Link ID: 17254 - Posted: 09.13.2012

By Ingrid Wickelgren In a room tucked next to the reception desk in a colorful lobby of a Park Avenue office tower, kids slide into the core of a white cylinder and practice something kids typically find quite difficult: staying still. Inside the tunnel, a child lies on her back and looks up at a television screen, watching a cartoon. If her head moves, the screen goes blank, motivating her to remain motionless. This dress rehearsal, performed at The Child Mind Institute, prepares children emotionally and physically to enter a real magnet for a scan of their brain. The scan is not part of the child’s treatment; it is his or her contribution to science. What scientists learn from hundreds to thousands of brain scans from children who are ill, as well as those who are not, is likely to be of enormous benefit to children in the future. The Child Mind Institute is a one-of-a-kind facility dedicated to the mental health of children. Its clinicians offer state-of-the-art treatments for children with psychiatric disorders. (For more on its clinical services see my previous post, “Minding Our Children’s Minds.”) In addition to spotting and treating mental illness, The Child Mind Institute is dedicated to improving both through science. Its researchers are helping build a repository of brain scans to better understand both ordinary brain development and how mental illness might warp that process. Tracking the developmental trajectory of mental illness is a critical, overlooked enterprise. Almost three quarters of psychiatric disorders start before age 24 and psychological problems in childhood often portend bona fide, or more severe, diagnoses in adults. If scientists can pinpoint changes that forecast a mental disorder, they might be able to diagnose an incipient disease, when it might be preventable, and possibly target the troublesome circuits through therapy. Certain brain signatures might also provide information about disease risk and prognosis, and about what types of treatments might work best for an individual. © 2012 Scientific American

Keyword: Development of the Brain; Schizophrenia
Link ID: 17253 - Posted: 09.13.2012

by Sarah C. P. Williams Scientists have enabled deaf gerbils to hear again—with the help of transplanted cells that develop into nerves that can transmit auditory information from the ears to the brain. The advance, reported today in Nature, could be the basis for a therapy to treat various kinds of hearing loss In humans, deafness is most often caused by damage to inner ear hair cells—so named because they sport hairlike cilia that bend when they encounter vibrations from sound waves—or by damage to the neurons that transmit that information to the brain. When the hair cells are damaged, those associated spiral ganglion neurons often begin to degenerate from lack of use. Implants can work in place of the hair cells, but if the sensory neurons are damaged, hearing is still limited. "Obviously the ultimate aim is to replace both cell types," says Marcelo Rivolta of the University of Sheffield in the United Kingdom, who led the new work. "But we already have cochlear implants to replace hair cells, so we decided the first priority was to start by targeting the neurons." In the past, scientists have tried to isolate so-called auditory stem cells from embryoid bodie—aggregates of stem cells that have begun to differentiate into different types. But such stem cells can only divide about 25 times, making it impossible to produce them in the quantity needed for a neuron transplant. © 2010 American Association for the Advancement of Science.

Keyword: Hearing; Stem Cells
Link ID: 17252 - Posted: 09.13.2012