By Nathan Seppa In science’s struggle to keep up with life on the streets, smoking cannabis for medical purposes stands as Exhibit A. Medical use of cannabis has taken on momentum of its own, surging ahead of scientists’ ability to measure the drug’s benefits. The pace has been a little too quick for some, who see medicinal joints as a punch line, a ruse to free up access to a recreational drug. But while the medical marijuana movement has been generating political news, some researchers have been quietly moving in new directions — testing cannabis and its derivatives against a host of diseases. The scientific literature now brims with potential uses for cannabis that extend beyond its well-known abilities to fend off nausea and block pain in people with cancer and AIDS. Cannabis derivatives may combat multiple sclerosis, Crohn’s disease and other inflammatory conditions, the new research finds. Cannabis may even kill cancerous tumors. Many in the scientific community are now keen to see if this potential will be fulfilled, but they haven’t always been. Pharmacologist Roger Pertwee of the University of Aberdeen in Scotland recalls attending scientific conferences 30 years ago, eager to present his latest findings on the therapeutic effects of cannabis. It was a hard sell. “Our talks would be scheduled at the end of the day, and our posters would be stuck in the corner somewhere,” he says. “That’s all changed.” © Society for Science & the Public 2000 - 2010

Keyword: Drug Abuse
Link ID: 14207 - Posted: 06.26.2010

by Andy Coghlan Fetuses aged 24 weeks or less do not have the brain connections to feel pain, according to a working party report published this week by the UK Royal College of Obstetricians and Gynaecologists (RCOG). Its conclusion is the latest to challenge the rationale for a law introduced in the US state of Nebraska in April. This law, which bans almost all abortions beyond 20 weeks of pregnancy, was introduced primarily on the grounds that the fetus feels pain. The report, which reviews recent scientific literature on the subject, also concludes that the fetus is sedated throughout pregnancy by chemicals such as adenosine contained in the amniotic fluid that surrounds it. Because the fetus is unable to feel pain before 24 weeks, no pain relief is needed for medical procedures up to that time, including abortion, the report concludes. This reverses the position the RCOG took in its previous report on fetal pain in 1997, which supported the use of analgesia. "We have now advised that analgesia is not indicated up to 24 weeks," says Allan Templeton, chairman of the working group that produced the report. He adds that administering painkillers carries risks of harming the fetus. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch; Development of the Brain
Link ID: 14206 - Posted: 06.26.2010

by Ewen Callaway Why would anyone put people who are afraid of snakes into a brain scanner, alongside the cause of their fear? To work out what is going on in the brain when people display courage, of course. This was the strategy used by Uri Nili and Yadin Dudai, at the Weizmann Institute in Rehovot, Israel, and it showed that courage does not come when we completely banish fear, but through overcoming it enough to act. "A firefighter having to go into a burning building should display courage, but that firefighter is not fearless," Dudai says. Their observations suggest an area of the brain that could be targeted in efforts to rid people of their phobias. The researchers examined the brain activity of 39 people with an abnormally strong fear of snakes as they lay on their backs in a functional MRI (fMRI) brain scanner. They were given the option to move a venomless 1.5-metre-long corn snake further away from their heads along a conveyer belt, or to bring it closer, to within a distance as small as 20 centimetres. One participant panicked so much that they had to withdraw from the study, and all said they were scared when they had to choose which way to move the snake. The nearer the snake was, the more scared volunteers said they felt. © Copyright Reed Business Information Ltd.

Keyword: Emotions; Stress
Link ID: 14205 - Posted: 06.26.2010

By ALICIA CHANG LOS ANGELES - Dozens of people who were blinded or otherwise suffered severe eye damage when they were splashed with caustic chemicals had their sight restored with transplants of their own stem cells — a stunning success for the burgeoning cell-therapy field, Italian researchers reported Wednesday. The treatment worked completely in 82 of 107 eyes and partially in 14 others, with benefits lasting up to a decade so far. One man whose eyes were severely damaged more than 60 years ago now has near-normal vision. "This is a roaring success," said ophthalmologist Dr. Ivan Schwab of the University of California, Davis, who had no role in the study — the longest and largest of its kind. Stem cell transplants offer hope to the thousands of people worldwide every year who suffer chemical burns on their corneas from heavy-duty cleansers or other substances at work or at home. The approach would not help people with damage to the optic nerve or macular degeneration, which involves the retina. Nor would it work in people who are completely blind in both eyes, because doctors need at least some healthy tissue that they can transplant. In the study, published online by the New England Journal of Medicine, researchers took a small number of stem cells from a patient's healthy eye, multiplied them in the lab and placed them into the burned eye, where they were able to grow new corneal tissue to replace what had been damaged. Since the stem cells are from their own bodies, the patients do not need to take anti-rejection drugs. Copyright 2010 The Associated Press.

Keyword: Vision; Stem Cells
Link ID: 14204 - Posted: 06.24.2010

By GINA KOLATA Dr. Daniel Skovronsky sat at a small round table in his corner office, laptop open, waiting for an e-mail message. His right leg jiggled nervously. A few minutes later, the message arrived — results that showed his tiny start-up company might have overcome one of the biggest obstacles in diagnosing Alzheimer’s disease. It had found a dye and a brain scan that, he said, can show the hallmark plaque building up in the brains of people with the disease. The findings, which will be presented at an international meeting of the Alzheimer’s Association in Honolulu on July 11, must still be confirmed and approved by the Food and Drug Administration. But if they hold up, it will mean that for the first time doctors would have a reliable way to diagnose the presence of Alzheimer’s in patients with memory problems. And researchers would have a way to figure out whether drugs are slowing or halting the disease, a step that “will change everyone’s thinking about Alzheimer’s in a dramatic way,” said Dr. Michael Weiner of the University of California, San Francisco, who is not part of the company’s study and directs a federal project to study ways of diagnosing Alzheimer’s. Still, the long tale behind this finding shows just how difficult this disease is and why progress toward preventing or curing it has been so slow. Ever since Alzheimer’s disease was described by a German doctor, Alois Alzheimer, in 1906, there was only one way to know for sure that a person had it. A pathologist, examining the brain after death, would see microscopic black freckles, plaque, sticking to brain slices like barnacles. Without plaque, a person with memory loss did not have the disease. Copyright 2010 The New York Times Company

Keyword: Alzheimers; Brain imaging
Link ID: 14203 - Posted: 06.24.2010

Michael J. Thorpy, M.D. Michael J. Thorpy, M.D. “Everybody suffers from a few sleepless nights, but most people do not suffer from the disorder of insomnia,” explains Dr. Michael Thorpy, a neurologist and director of the Sleep-Wake Disorders Center at Montefiore Medical Center in the Bronx. “Insomnia disorder typically occurs when the sleeplessness occurs for at least one month, though even a few days of bad sleep may be sufficient to require treatment.” Shelby Freedman Harris, Psy.D. Shelby Freedman Harris, Psy.D. Dr. Thorpy and Shelby Freedman Harris, a psychologist and director of the center’s behavioral sleep medicine program, recently took readers’ questions about insomnia on the Consults blog. Here, Dr. Thorpy and Dr. Harris respond to a reader inquiring whether insomnia is always a result of some underlying condition like stress or pain, or whether it can exist as a standalone disorder. Q. Is insomnia always coupled with an underlying cause (chronic pain, stress, anxiety disorder, etc) or is it truly possible to have insomnia and not have any underlying condition? Moreover, if you solve the underlying condition of your insomnia, is it possible to still suffer from insomnia? wiparker824, Chandler, Ariz. Great question, and something that has caused a lot of debate in sleep medicine over the years. Briefly, you can have an underlying condition and insomnia. But once the original condition is treated, the insomnia may remain and require its own treatment. Copyright 2010 The New York Times Company

Keyword: Sleep
Link ID: 14202 - Posted: 06.24.2010

By Jeremy Laurance, Health Editor To sceptics of alternative medicine, it will come as a surprise. Applying magnets to the brains of Alzheimer's disease sufferers helps them understand what is said to them. The finding by Italian scientsts, who conducted a randomised controlled trial of the treatment, suggests that magnets may alter "cortical activity" in the brain, readjusting unhealthy patterns caused by disease or damage. The study was small, involving just 10 patients, and the results are preliminary. But the scientists from Brescia and Milan say they "hold considerable promise, not only for advancing our understanding of brain plasticity mechanisms, but also for designing new rehabilitation strategies in patients with neurodegenerative disease." Sweeping claims are made for magnet therapy, including stimulating hair growth, boosting energy and warding off arthritis. Magnetic bracelets and jewellery, hairbrushes, insoles and even dog bowls are a lucrative branch of the alternative medicine industry. Evidence for most of these claims is dubious or non-existent. But one product gained sufficient credence in orthodox circles to to be made available on the NHS. Since 2006 a device called the 4UlcerCare – a strap containing four magnets that is wrapped around the leg – has been available on prescription from GPs. Its maker, the Bristol-based firm Magnopulse, claims that it speeds the healing of leg ulcers and prevents their recurrence. It is believed that the magnets stimulate the circulation but it is not known how. ©independent.co.uk

Keyword: Alzheimers
Link ID: 14201 - Posted: 06.24.2010

By Larry O'Hanlon It turns out that most parents are freaking kids out when children are about to undergo a painful medical procedure. A new study has started to crack the mystery behind why saying, "Don't worry," to kids causes them to be more anxious than ever, while children whose parents just talk about something else cope better. "It seems counterintuitive that reassurance can hurt," said Meghan McMurty of the Departments of Psychology, Pediatrics and Psychiatry at Dalhousie University in Halifax, Nova Scotia. But it's a well established fact that when parents try to soothe kids facing a needle, it nearly always backfires. To find out just what aspects of reassurance were heightening the fear in children, McMurty and her colleagues recruited 100 children between ages 5 and 10 and their parents. All the children were having blood drawn for tests in an outpatient blood lab. By videotaping the parents' behaviors and playing them back to children before they left the clinic, along with video vignettes by actors recreating the same behaviors, the researchers hoped to separate out the effects of whether the parents reassured them, their facial expressions as well as the tones of parents' voices. The children rated what they saw in the videos. © 2010 Discovery Communications, LLC.

Keyword: Pain & Touch
Link ID: 14200 - Posted: 06.24.2010

by Andy Coghlan A FAULTY internal clock in the cells in the pancreas that produce insulin could be behind type 2 diabetes - a condition in which the body is unable to produce or use insulin properly. The finding suggests that disruption of natural night and day cycles through artificial lighting may be a factor in the emergence of type 2 diabetes in adults. It also fits with studies showing that shift workers are unusually prone to the condition. Insulin is produced by beta cells to control glucose levels in the blood. Joseph Bass of Northwestern University in Evanston, Illinois, and colleagues grew mouse beta cells in the lab to monitor insulin secretion. They found that beta cells lacking circadian "clock" genes produced 50 per cent less insulin, showing that these genes are essential for normal insulin production (Nature, DOI: 10.1038/nature09253). Likewise, live mice with disrupted clock genes rapidly developed type 2 diabetes. The next step, says Bass, is to identify the "switch" in beta cells that responds to the clock, and use it to develop a treatment. "The key thing the researchers have shown is that disruption of this internal clock causes a defect in insulin secretion," says Noel Morgan of the Peninsula Medical School in Exeter, UK, who studies type 1 diabetes, in which the body's own immune system destroys its beta cells. © Copyright Reed Business Information Ltd.

Keyword: Biological Rhythms; Obesity
Link ID: 14199 - Posted: 06.24.2010

David Perlman, Chronicle Science Editor In the Afar language of Ethiopia, he's called Kadanuumuu, and to the Ethiopia-born anthropologist who found his bones, he could be called "Big Man," or even "Big Guy." But to everyone else interested in the discovery of new fossil evidence for the ancestry of the human lineage, he'll be known as "Lucy's great-grandfather." A team of noted fossil hunters reports this week the discovery of a creature in the same species as Lucy, but at least 400,000 years older than that famed female whose discovery in 1974 was hailed as a major step in piecing together the story of human evolution. From the newfound fossils, their leading discoverer says scientists have determined that the creature - nicknamed Kadanuumuu, but known scientifically as Australopithecus afarensis - walked upright on two feet. It means that bipedalism was fully established as a normal way of life in human ancestry at least 3.58 million years ago, when this remote forebear lived. The finding is reported in the current issue of Proceedings of the National Academy of Sciences. Yohannes Haile-Selassie, director of anthropology at the Cleveland Museum of Natural History who earned his doctorate at UC Berkeley, led the international team of fossil hunters in Ethiopia's arid Afar Desert that discovered evidence of the creature in 2005. They first found its single lower arm bone and kept digging for five more years before they assembled enough bones to identify it. © 2010 Hearst Communications Inc.

Keyword: Evolution
Link ID: 14198 - Posted: 06.24.2010

By Jesse Bering There must be something in the water here in Lanesboro, Minnesota, because last night I dreamt of an encounter with a very muscular African-American centaur, an orgiastic experience with – gasp – drunken members of the opposite sex and (as if that weren’t enough) then being asked by my hostess to wear a white wedding dress while giving a scientific keynote presentation. “Does it make me look too feminine?” “Not at all,” she assured me, “it’s a man’s dress.” Now Freud might raise his eyebrows at such a lurid dreamscape, but if these images represent my repressed sexual yearnings, then there’s a side of me that I apparently have yet to discover. But I doubt that this is the case. Dreams with erotic undertones are like most other dreams during REM sleep—runaway trains with a conductor who is helpless to do anything about the surrealistic directions they take. Rather, if you really want to know about a person’s hidden sexual desires, then find out what’s on his or her mind’s eye during the deepest throes of masturbation. This conjuring ability to create fantasy scenes in our heads that literally bring us to orgasm when conveniently paired with our dexterous appendages is an evolutionary magic trick that I suspect is uniquely human. It requires a cognitive capacity called mental representation (an internal “re-presentation” of a previously experienced image or some other sensory input) that many evolutionary theorists believe is a relatively recent hominid innovation. © 2010 Scientific American,

Keyword: Sexual Behavior; Evolution
Link ID: 14197 - Posted: 06.24.2010

By Dara Greenwood If your children are like 99 percent of boys and 94 percent of girls, they play video games. And, if they are like 50 percent of boys and 14 percent of girls, they prefer games with “mature” – read: violent -- themes, such as Grand Theft Auto, an urban dystopia of gun fights, car chases, pole dancers and prostitutes, where blood splatters realistically on the “camera lens.” Should you worry whether such a game will warp your children’s minds? A new paper by Cheryl Olson, a public health specialist at Harvard, suggests the answer may be: au contraire. Olson surveyed children’s reported motivations for video game playing and found that their top rated choices were to have fun, compete well with others, and to be challenged. She then elaborates on the psychological benefits such play might afford, describing how video games facilitate self-expression, role play, creative problem-solving, cognitive mastery, positive social interactions and leadership. Sounds more utopian than dystopian, right? If only it were that simple. As laudable as it is to debunk negative stereotypes about non-violent game play, it is less laudable to gloss over the negative effects of violent video games. Olson’s rosy spin on violent video games positions her on one side of a heated academic debate with staggering stakes in policy and industry. (See recent salvos here, here and here.) One contingent warns that violent games reduce empathy and effective anger management skills, and promote aggression. The other contingent rebuts that such research plays into “moral panic,” exaggerates the negative impact and ignores the positive effects of violent game play. Given the sheer popularity of violent video games, their psychological impact is an urgent issue for society, and for the millions of parents whose children dive into virtual worlds for hours every day. Let’s take a closer look at the research in question. © 2010 Scientific American,

Keyword: Aggression
Link ID: 14196 - Posted: 06.24.2010

How much sleep is enough? Is how sleepy you feel a good judge of whether or not you are getting enough sleep? If you get less sleep than some ideal amount but you feel fine, could you be damaging your health anyway? Are we getting less than we used to? Recent research provides some surprising answers. Adults typically need seven to nine hours of sleep each night to feel fully rested and function at their best. However, Americans are getting less sleep than they did in the past. A 2005 National Sleep Foundation poll found that Americans averaged 6.9 hours of sleep per night, which represents a drop of about two hours per night since the 19th century, one hour per night over the past 50 years, and about 15 to 25 minutes per night just since 2001. Unfortunately, we are not very good at perceiving the detrimental effects of sleep deprivation. Researchers at the University of Pennsylvania restricted volunteers to less than six hours in bed per night for two weeks. The volunteers perceived only a small increase in sleepiness and thought they were functioning relatively normally. However, formal testing showed that their cognitive abilities and reaction times progressively declined during the two weeks. By the end of the two-week test, they were as impaired as subjects who had been awake continuously for 48 hours. COMPLETE COVERAGE: Keys to a Healthy Life » Moreover, cognitive and mood problems may not be the only consequences of too little sleep. Researchers at the University of Chicago have shown that too little sleep changes the body’s secretion of some hormones. The changes promote appetite, reduce the sensation of feeling full after a meal, and alter the body’s response to sugar intake—changes that can promote weight gain and increase the risk of developing diabetes. Since then, multiple epidemiological studies have shown that people who chronically get too little sleep are at greater risk of being overweight and developing diabetes. © 2010 Newsweek, Inc

Keyword: Sleep
Link ID: 14195 - Posted: 06.24.2010

By PAM BELLUCK No one who knows Justin Kaplan would ever have expected this. A Pulitzer Prize-winning historian with a razor intellect, Mr. Kaplan, 84, became profoundly delirious while hospitalized for pneumonia last year. For hours in the hospital, he said, he imagined despotic aliens, and he struck a nurse and threatened to kill his wife and daughter. “Thousands of tiny little creatures,” he said, “some on horseback, waving arms, carrying weapons like some grand Renaissance battle,” were trying to turn people “into zombies.” Their leader was a woman “with no mouth but a very precisely cut hole in her throat.” Attacking the group’s “television production studio,” Mr. Kaplan fell from his hospital bed, cutting himself and “sliding across the floor on my own blood,” he said. The hospital called security because “a nurse was trying to restrain me and I repaid her with a kick.” Mr. Kaplan’s hallucinations lifted as doctors treated his pneumonia. But hospitals say many patients are experiencing such inexplicable disorienting episodes. Doctors call it “hospital delirium,” and are increasingly trying to prevent or treat it. Disproportionately affecting older people, a rapidly growing share of patients, hospital delirium affects about one-third of patients over 70, and a greater percentage of intensive-care or postsurgical patients, the American Geriatrics Society estimates. Copyright 2010 The New York Times Company

Keyword: Alzheimers
Link ID: 14194 - Posted: 06.24.2010

By JR Minkel Marijuana gives people with schizophrenia a quick rush but worsens their psychotic symptoms within a few hours, a new study reveals. Researchers in the Netherlands recruited 48 psychiatric patients and 47 healthy people to record what they were doing and how they felt 12 times a day for six days. All the study participants were regular pot smokers. The results showed that schizophrenia sufferers were more sensitive than healthy individuals to both the positive and negative effects of marijuana, or cannabis. "People feel better when they use cannabis, and that's logical, because otherwise they wouldn't use cannabis," said study researcher Cecile Henquet of Maastricht University Medical Center in the Netherlands. "In spite of that, in the long run it's not so good for their psychotic symptoms." Researchers have long wondered whether the mentally ill are using reefer to alleviate the classic symptoms of the disease: delusions, hallucinations and jumbled thoughts. The new studies turn that reasoning on its head, said Deepak Cyril D'Souza, a psychiatrist at Yale University who was not involved in the study. "What the data clearly show are that, if anything, the core symptoms of schizophrenia actually get worse after using cannabis," he said. © 2010 LiveScience.com

Keyword: Schizophrenia; Drug Abuse
Link ID: 14193 - Posted: 06.24.2010

By Ferris Jabr Here's a little experiment. You know "Greensleeves"—the famous English folk song? Go ahead and hum it to yourself. Now choose the emotion you think the song best conveys: (a) happiness, (b) sadness, (c) anger or (d) fear. Almost everyone thinks "Greensleeves" is a sad song—but why? Apart from the melancholy lyrics, it's because the melody prominently features a musical construct called the minor third, which musicians have used to express sadness since at least the 17th century. The minor third's emotional sway is closely related to the popular idea that, at least for Western music, songs written in a major key (like "Happy Birthday") are generally upbeat, while those in a minor key (think of The Beatles' "Eleanor Rigby") tend towards the doleful. The tangible relationship between music and emotion is no surprise to anyone, but a study in the June issue of Emotion suggests the minor third isn't a facet of musical communication alone—it's how we convey sadness in speech too. When it comes to sorrow, music and human speech might speak the same language. In the study, Meagan Curtis of Tufts University's Music Cognition Lab recorded undergraduate actors reading two-syllable lines—like "let's go" and "come here"—with different emotional intonations: anger, happiness, pleasantness and sadness (listen to the recordings here). She then used a computer program to analyze the recorded speech and determine how the pitch changed between syllables. Since the minor third is defined as a specific measurable distance between pitches (a ratio of frequencies), Curtis was able to identify when the actors' speech relied on the minor third. What she found is that the actors consistently used the minor third to express sadness. © 2010 Scientific American

Keyword: Language; Emotions
Link ID: 14192 - Posted: 06.24.2010

By Laura Beil Throughout the leaner epochs of human history, when food supplies were unreliable, the species would not have survived without a way to hoard calories for later use. That is, without fat. Once a meal has supplied the body’s immediate energy needs, any unused fuel gets converted into long molecules called triglycerides, which are dispatched to fatty tissue where they wait for a signal that the body needs them. But in an era of high-calorie smorgasbords and 24/7 convenience, unused energy can just pile on year after year, a major reason why one-third of the U.S. adult population is struggling with obesity. Laws of physics — the ones about conservation of matter and energy — dictate that schemes for burning off all that fat are pretty much limited to two options: Diet to lower the amount of energy consumed, or exercise to increase the amount of energy the body needs. Most current antiobesity drugs work on the diet half of the equation, helping people limit calories by dampening appetite or by interfering with the digestion of food. Approaches that knock down cravings are based largely on research in the 1990s that worked out some of the biological underpinnings of hunger. More recently, though, experiments have deepened scientists’ understanding of the way fat locks up and releases surplus calories — providing hope that future therapies may offer a kind of virtual exercise. While there’s still no getting around the laws of thermodynamics, scientists are getting closer to finding ways to trick fat cells into releasing their stockpiled fuel. © Society for Science & the Public 2000 - 2010

Keyword: Obesity
Link ID: 14191 - Posted: 06.24.2010

By Rachel Ehrenberg Truster-Pro and the Vericator may sound like devices Wile E. Coyote would order from the Acme Co., but they are real technologies for detecting lies. Unlike the traditional polygraph, which zeroes in on factors such as pulse and breathing rate, these analyzers aim to assess veracity based solely on speech. Police departments shell out thousands of dollars on such devices — known collectively as voice stress analyzers — in an attempt to tune in to vocal consequences of lying. Airports are considering versions for security screening purposes, and insurance companies may employ the polygraph alternatives to detect fraud. But beyond their crime-fighting objective, these tools have something less noble in common with their predecessor: a poor track record in actually telling truth from deception. Scientists evaluating Truster-Pro, the Vericator and newer analyzer models repeatedly report lackluster results. Now research finds that two of the most commonly used voice stress analyzers can discern lies from truth at roughly chance levels — no better than flipping a coin. “Quite frankly, they’re bogus. There’s no scientific basis whatsoever for them,” says John H.L. Hansen, head of the Center for Robust Speech Systems at the University of Texas at Dallas. “Law enforcement agencies — they’re spending a lot of money on these things. It just doesn’t make sense.” © Society for Science & the Public 2000 - 2010

Keyword: Stress
Link ID: 14190 - Posted: 06.24.2010

by Ewen Callaway Baby rats are born explorers, able to map their world before they crawl so much as a centimetre. So suggest two studies that found newborn rats open their eyes equipped with the same brain mechanisms that adults use for navigation. Rats, and possibly humans too, rely on three kinds of neuron to navigate: direction cells fire when an animal faces a specific direction; place cells fire in a specific location and only that location; and grid cells fire at regular intervals as the animal moves trough space, creating something like an internal grid for their world. These cells have been studied in older rodents – and observed in adult humans – but researchers know little about how such cells come to guide navigation, says Edvard Moser, a neuroscientist at the Norwegian University of Science and Technology in Trondheim. To find out how and when these cells develop, Moser and his colleagues implanted microelectrodes into the brains of 2-week-old rat pups. They then recorded the electrical activity of the cells as the animals opened their eyes for the first time and began to explore their cage. Another group led by Tom Wills and John O'Keefe at University College London performed similar tests. Without any real exposure to the world through movement or sight, the pups seemed to have direction and place cells that worked nearly as well as those of adults, both Moser and Wills found. Moser's team found the grid cells working right away, while Wills's suggest these cells start firing a few days later. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain
Link ID: 14189 - Posted: 06.24.2010

Cold sensing in the newborn develops well after birth, suggests a new American study. The researchers used mice for the study and found neural circuits in newborn mice take around two weeks to become fully active. The study, led by David McKemy of the University of Southern California, appears online in Neuroscience. McKemy, an assistant professor of neurobiology, said: "About three or four days before the animal is born, the protein is expressed. However, the axons of these nerves going into the spinal cord are not fully formed until probably two weeks after birth." The delay in development of cold sensing is plausible, added McKemy. He said: "In the womb, when would we ever feel cold?" By contrast, mice are born with a keen sense of smell, which they need to breast feed successfully. Direct study of the cold sensing protein TRPM8 in humans is not yet possible. While sensory development differs in mice and humans - mice are born blind, for example - the study suggests a possible biological basis for findings of altered cold sensitivity in premature infants. © Copyright Sify Technologies Ltd, 1998-2010.

Keyword: Pain & Touch; Development of the Brain
Link ID: 14188 - Posted: 06.24.2010