Just one extra hour of sleep a day appears to lower the risk of developing calcium deposits in the arteries, a precursor to heart disease, US researchers said on Tuesday. The finding adds to a growing list of health consequences - including weight gain, diabetes and high blood pressure - linked to getting too little sleep. "We found that people who on average slept longer were at reduced risk of developing new coronary artery calcifications over five years," said Diane Lauderdale of the University of Chicago Medical Center, whose study appears in the Journal of the American Medical Association. "It was surprisingly strong," Lauderdale said. Calcium deposits in the coronary arteries are considered a precursor of future heart disease. "It's a very early marker of future risk," she said. Unlike other studies looking at the risks of getting too little sleep, which use people's own estimates of their sleep patterns, Lauderdale's team set out to measure actual sleep patterns. They fitted 495 people aged 35 to 47 with sophisticated wrist bands that tracked subtle body movements. Information from these recorders was fed into a computer program that was able to detect actual sleep patterns. The team used special computed tomography, or CT, scans to assess the buildup of calcium inside heart arteries, performing one scan at the start of the study and one five years later. © Copyright Reed Business Information Ltd

Keyword: Sleep
Link ID: 12383 - Posted: 06.24.2010

By Rachel Zelkowitz Talk about Dr. Jekyll and Mr. Hyde. Misfolded proteins known as prions cause mad cow disease and other fatal neurodegenerative illnesses. But in their properly folded form, the proteins may be important to survival, helping mice and other animals keep their sniffing skills sharp, new research shows. Prions get the bad reputation--and the lion's share of research attention--but interest in the normal form of prion proteins is increasing. Brain tissue is particularly high in these proteins, and a growing body of research has shown that they help neurons conduct copper and may even protect them from destruction by rogue chemicals in the body. But no one had pegged prion proteins to a particular neurological function such as sight or smell. That's changed, thanks to an intriguing finding by electrophysiologist Stuart Firestein of Columbia University. Firestein and colleagues were studying the sense of smell in mice when they noticed high levels of normal prion protein (PrPc) in the cells that make up the animals' olfactory systems. Wondering whether the protein might play a role in this sense, the researchers hid bits of peanut butter cookies in the shredded bedding of a cage. They then timed how long it took both normal mice and rodents genetically engineered to not make PrPc to sniff out the snack. Normal mice spent an average of 73 seconds searching for the treat before they found it, three times faster than their PrPc-free counterparts. Six of the 20 PrPc-free mice never found the cookie at all, the team reports this week in Nature Neuroscience. © 2008 American Association for the Advancement of Science.

Keyword: Prions; Chemical Senses (Smell & Taste)
Link ID: 12382 - Posted: 06.24.2010

by Jessica Griggs The deep sea is full of surprises, and the four-eyed spookfish is up there with the best of them. It is the first vertebrate found with eyes that use mirrors, rather than a lens, to focus light. In clear water, sunlight can penetrate to a depth of 1000 metres, so some deep-sea fish have developed tubular, upward-looking eyes. "It is like having a telescope on your head that points towards the surface," says Ron Douglas from City University London. However, sunlight is only part of the story. The most important source of light at that depth is other creatures, as 80% emit their own light, called bioluminescence. The unusual spookfish was caught in the deep waters between Samoa and New Zealand, but no one on the research boat knew what it was. "It caught my attention because it looked like it had four eyes, and vertebrates with four eyes don't exist," says Douglas. It turns out that the spookfish (Dolichopteryx longipes) actually has just two eyes, but each eye has two parts, one looking upwards and the other down. The team found that the part looking down uses thousands of tiny reflective crystals – acting like mirrors – that are angled in slightly different directions to focus light onto the retina. This is completely different to a typical fish eye, which uses a single lens to bend light onto a focal point, similar to the way the human eye works. © Copyright Reed Business Information Ltd

Keyword: Vision; Evolution
Link ID: 12381 - Posted: 06.24.2010

By Nathan Seppa People who kick and lash out while fast asleep in bed face a high risk of developing Parkinson’s disease and certain forms of dementia, scientists report online December 24 in Neurology. The condition, called rapid-eye-movement sleep behavior disorder, results when a person’s muscles fail to relax during sleep. “During REM sleep, with the most vivid dreaming, mostly we’re paralyzed,” says neurologist Ronald Postuma of McGill University in Montreal. “The brain shuts off muscle tone. We want to run but we can’t.” But in people with REM sleep behavior disorder, muscle tone isn’t shut down. “As a consequence, you act out your dreams,” he says. People with the condition have been known to break a hand on a wall, hurt a spouse or fall out of bed, he says. Postuma and his colleagues have monitored the progress of 93 people who were diagnosed with REM sleep behavior disorder between 1989 and 2006 at Sacré Coeur Hospital, also in Montreal. The team followed some patients for 15 years or more. Roughly 80 percent are men, and most were enrolled while in their 60s. Of the 93 participants, 26 have developed a neurodegenerative disease during the study years. Of these, 14 developed Parkinson’s disease, and seven developed Lewy body dementia, which is marked by the appearance of Lewy bodies — abnormal protein deposits — in the brain. Four other study participants were diagnosed with Alzheimer’s disease, but the researchers suspect that these patients might actually have Lewy body dementia. One person developed a less common neurodegenerative condition called multiple system atrophy. © Society for Science & the Public 2000 - 2008

Keyword: Parkinsons; Sleep
Link ID: 12380 - Posted: 06.24.2010

Experiments in rats may have revealed why some painkilling drugs are less effective in women compared with men. US researchers found brain differences affecting the potency of opioids such as morphine. The Journal of Neuroscience study also found drug effectiveness varied during the rats' menstrual cycles. Another expert said it showed the growing importance of tailoring pain relief to match the individual needs of the patient. Morphine remains one of the most widely used drugs to alleviate severe persistent pain and doctors have noticed that it frequently does not work as well in women. However, the study from Georgia State University claims to be the first to pinpoint the reason why. It looked closely at a tiny area of the brain called the periaqueductal grey area (PAG), which is important in the way that pain signals are interpreted. Many neurons in this region have, on their surface, "receptors" designed to receive and lock onto the molecules found in opioid drugs. These "mu-opioid receptors", when locked onto an opioid drug, send a message telling the brain to stop responding to pain signals, reducing the sensation of pain. The Georgia State team found that, in the rat brain, females had a lower level of mu-opioid receptors in this part of the brain, suggesting that the potential potency of morphine is much reduced. Additional tests suggested that the response to morphine varied depending on which part of the menstrual cycle the female rat was in. Professor Anne Murphy, who led the research, said: "It is increasingly clear that morphine is significantly less potent in women compared with men - until now, the mechanism driving the phenomenon was unknown. "Additional research with the inclusion of female subjects needs to be devoted to determining a more potent treatment for persistent pain in women." (C)BBC

Keyword: Pain & Touch; Sexual Behavior
Link ID: 12379 - Posted: 12.25.2008

CHICAGO - U.S. scientists have created the first human model for studying a devastating nerve disease, which allows them to watch how the disease develops and could help researchers find a way to treat it. Using skin cells from a child with spinal muscular atrophy, a genetic disease that attacks motor neurons in the spinal cord, researchers grew batches of nerve cells with the same genetic defects. The finding allowed scientists to watch the nerve cells die off. "Now we can start from the beginning of development and replay the disease process in the lab dish," Clive Svendsen of the University of Wisconsin-Madison said in a telephone interview. The finding, reported on Sunday in the journal Nature, marks the latest advance in research that reprograms ordinary cells to look and act like embryonic stem cells — the master cells of the body that can produce any type of tissue or blood cell. Spinal muscular atrophy is the most common cause of childhood death caused by a genetic mutation, Svendsen said. It is caused by a deficiency of a protein called SMN, for survival of motor neurons. "That SMN protein is important for motor neuron survival. They are the cells that make muscles move," Svendsen said. Copyright 2008 Reuters.

Keyword: Movement Disorders; Genes & Behavior
Link ID: 12378 - Posted: 06.24.2010

By Amelia Tomas Spiders are bizarre sex freaks. But it’s all harmless fun ... no wait, actually it’s very harmful. Girl kills guy or guy kills girl — there’s shrill crying, plugged orifices, torn-off genitals, eaten body parts, and psychedelic rituals. And you thought humans had crazy sex lives? Mounting evidence in recent years shows just how crazy spider sex is. For example, in the case of redback spiders (Latrodectus hasselti), courtship tends to last an average of 50 minutes when males are competing head-to-head for mating rights and 4.5 hours for single, non-competing males. It seems as if the larger male redbacks would always be favored, but scientists recently discovered that the smaller ones actually get more action than their bigger counterparts because they mature faster and are quicker on their feet. Meanwhile, mature jumping spiders sport crucial glowing patches on their bodies to lure in mates, as if dressed for a rave. The males exhibit UV-reflecting scales that glow in bright white and green, and the females’ have front appendages that similarly glow in a bright green hue. Turns out, females and males will ignore each other if not seen under full-spectrum light, suggesting that both partners must show their glowing bodies to prove their health before courtship can proceed. © 2008 LiveScience.com.

Keyword: Sexual Behavior
Link ID: 12377 - Posted: 06.24.2010

By MARC E. AGRONIN, M.D. The forest still stands, but the people are gone. Only a stone memorial guards their place, surrounded by tall grasses that hide bits of ash and bone deep beneath their roots. On this spot on Feb. 4, 1942, more than 920 Jewish men, women and children from the town of Rakov in what is now Belarus were rounded up by the Nazis and herded into the synagogue. Several shrieking children were stabbed with bayonets and thrown over the heads of the weeping Jews just before the doors and windows were sealed and the building was doused with kerosene. An unspeakable scene of wailing ensued as the once vibrant Jewish community was annihilated in the fire. My patient, now 98, still weeps when he describes witnessing this horror from a hidden perch in a tree. He gasps audibly when he recalls watching his father being pummeled by a Nazi soldier before he was thrust into the doomed crowd. When this survivor first told me his story, I was speechless. He held tight to my arm, and I imagined myself as the branches of the tree that supported him during this trauma. I was now a witness. As his psychiatrist I am obliged to ease his suffering, but no medicine of mine can touch such a memory. I have tried hard to understand how he and others managed to mentally survive such traumatic experiences. These aging Holocaust survivors, in particular, have taught me what I have come to call “lessons from fire.” Copyright 2008 The New York Times Company

Keyword: Learning & Memory; Stress
Link ID: 12376 - Posted: 06.24.2010

By NATALIE ANGIER When considering the behavior of putative scam operators like Bernard “Ponzi scheme” Madoff or Rod “Potty Mouth” Blagojevich, feel free to express a sense of outrage, indignation, disgust, despair, amusement, schadenfreude. But surprise? Don’t make me laugh. Sure, Mr. Madoff may have bilked his clients of $50 billion, and Governor Blagojevich, of Illinois, stands accused of seeking personal gain through the illicit sale of public property — a United States Senate seat. Yet while the scale of their maneuvers may have been exceptional, their apparent willingness to lie, cheat, bluff and deceive most emphatically was not. Deceitful behavior has a long and storied history in the evolution of social life, and the more sophisticated the animal, it seems, the more commonplace the con games, the more cunning their contours. In a comparative survey of primate behavior, Richard Byrne and Nadia Corp of the University of St. Andrews in Scotland found a direct relationship between sneakiness and brain size. The larger the average volume of a primate species’ neocortex — the newest, “highest” region of the brain — the greater the chance that the monkey or ape would pull a stunt like this one described in The New Scientist: a young baboon being chased by an enraged mother intent on punishment suddenly stopped in midpursuit, stood up and began scanning the horizon intently, an act that conveniently distracted the entire baboon troop into preparing for nonexistent intruders. Copyright 2008 The New York Times Company

Keyword: Emotions; Evolution
Link ID: 12375 - Posted: 06.24.2010

By Moheb Costandi The body image is a mental representation of one's physical appearance, constructed by the brain from past experiences and present sensations. It is an essential component of self-identity, which, when altered, can have dramatic effects on how one perceives oneself. For example, a small proportion of migraine sufferers experience visual hallucinations just before the onset of a headache, in which the body parts appear larger or smaller than they actually are. Lewis Carroll, who is known to have suffered from migraines, documented such hallucinations in Alice in Wonderland.

 These body image distortions can have bizarre consequences. Otherwise healthy people report that they have always percived a part of their body as feeling "wrong," and opt to have it removed by amputation; some brain-damaged or psychiatric patients experience alien hand syndrome, in which they deny ownership of a limb, and insist that it is under the control of external forces. Our perception of our own body can, of course, be easily manipulated. As we walk through a house of mirrors at a fair, for example, we may view ourselves as being very short and fat one minute, and then very tall and thin the next. By looking through a pair of binoculars, a limb can be made to appear disproportionately large or small. © 1996-2008 Scientific American Inc.

Keyword: Pain & Touch
Link ID: 12374 - Posted: 06.24.2010

by Justin Mullins The number of people suffering seriously impaired vision due to damaged retinas is increasing in the developed world, as populations age and diabetes becomes more common. The search for a technological solution to the problem has led to growing interest in "bionic eyes". Devices developed so far have usually involved installing a silicon chip into the eye to electrically stimulate the retina's nerves in response to light. Some impressive results have been achieved in this way, but implanted chips do have drawbacks. Their relatively large size means they block light that would have fallen on healthy parts of the retina and they can also cause tissue damage, such as tearing. So Jeffrey Olsen at the University of Colorado Hospital has come up with another method entirely – amplifying the light that reaches the retina using the eye's still functioning light-sensitive cells. Light amplification could be achieved by implanting quantum dots – nanoscale specks of semiconductor – into the retina, he says. These fluoresce when hit by photons and would have the effect of making any received retinal image brighter. © Copyright Reed Business Information Ltd.

Keyword: Vision; Robotics
Link ID: 12373 - Posted: 06.24.2010

Alison Abbott A man with brain damage that makes him clinically blind can navigate an obstacle course, seemingly by using a primitive part of his brain to perceive the objects in his path. This remarkable ability, discovered through a chance observation, is shedding light on a curious phenomenon known as blindsight. The man, known as patient TN, was studied by a multinational team led by Beatrice de Gelder at Tilburg University in The Netherlands and Alan Pegna of the Geneva University Hospitals in Switzerland. The researchers tested TN extensively to confirm that he was completely blind. They used brain imaging to show that there was no activity in his visual cortex, the part of the brain that processes most of the information coming from the retina. They then persuaded TN to set his stick aside and walk down a corridor strewn with lab equipment. He was able to do so flawlessly, despite being unable to consciously see any of the obstacles. Head down and hands loose by his side, he twisted his body to slalom slowly but surely between a camera tripod and a swingbin, and neatly stepped around a random series of smaller items. "At first he was nervous," says de Gelder. "He said he wouldn't be able to do it because he was blind." The scientists broke into spontaneous cheers when he succeeded. The results are reported today in Current Biology1. © 2008 Nature Publishing Group,

Keyword: Vision
Link ID: 12372 - Posted: 06.24.2010

By Sara Coelho What would we do without bees? They give us honey and pollinate hundreds of staple food crops throughout the world. Now it seems that the insects may play yet another role in keeping us well fed: Their buzz protects crops and other plants from caterpillar damage. Caterpillars destroy plants by feeding on leaves, flowers, and fruits. But they have a predator of their own: the wasp. To defend itself, the caterpillar has developed sensory hairs that "feel" the air vibrations caused by the beating of wasp wings. If a wasp approaches, the caterpillar stops moving or drops off the plant for safety. Jürgen Tautz, a biologist at the University of Würzburg in Germany, wondered whether bees, whose wings beat with a similar frequency to those of wasps, would have a similar effect. Tautz and his Würzburg colleague Michael Rostás built two cube-shaped tents in the botanical garden of their university, each enclosing 10 bell pepper plants. They then placed about 10 beet armyworm caterpillars (Spodoptera exigua), a notorious crop pest, on each plant. One tent had a window connected to a beehive, and feeders filled with a sugar solution attracted bees inside. The second tent was closed to the outside world. After about 2 weeks, Tautz and Rostás collected the leaves from the bell pepper plants. © 2008 American Association for the Advancement of Science.

Keyword: Hearing
Link ID: 12371 - Posted: 06.24.2010

The brain protein which has a hand, when defective, in the lethal disease CJD may also be involved in aiding our sense of smell. Mice bred to lack the prion protein could not find buried food or choose between smells. Columbia University scientists said some symptoms of prion disease might be due to the loss of the protein's original role. The study was published in the journal Nature Neuroscience. The prion protein has historically received something of a bad press, being blamed in its misshapen form for degenerative brain diseases in humans and other animals. However, many scientists have been trying to uncover what it actually does when it is behaving correctly. Dr Stuart Firestein's team believe that one of these roles is to help us smell. While his prion-protein free mice were still able to detect scents, they had lost some higher functions which required that smell information to be analysed and processed by the brain. The scientists found changes in the communication between neurons in the nerve cells of the olfactory bulb, part of the forebrain which deals with odours. When the protein was restored to this part of the brain, the ability to discriminate between odours came back. The scientists said that while the discovery had no direct link to the diseases caused by faulty prion proteins, it might help account for some of the symptoms experienced by patients, which might be due to the failure of the proteins to do their normal job properly, rather than the damage caused by accumulation of defective prions. (C)BBC

Keyword: Prions; Chemical Senses (Smell & Taste)
Link ID: 12370 - Posted: 12.22.2008

By Bruce Bower It’s not mealtime for certain bottlenose dolphins living off Australia’s coast unless they sport cone-shaped sea sponges on their beaks. These mammals are not following a strange, marine-based dress code. Their behavior has been identified as the first clear case of tool use by wild dolphins or whales, a new study concludes. These dolphins dive to the bottom of deep channels and poke their sponge-covered beaks into the sandy ocean floor to flush out small fish that dwell there, says a team led by biologist Janet Mann of Georgetown University in Washington, D.C. Foragers then drop their sponges, gobble up available fish and retrieve the implements for another sweep, the scientists report online December 10 in PLoS ONE. Dolphins hold the sponge with the bottom of their beaks and can sweep away much more sand than they could otherwise. Mann’s team documented this behavior among 41 bottlenose dolphins, most of them female, out of a population of several thousand that inhabits Australia’s Shark Bay. The researchers estimate that sponge-carrying dolphins, or spongers for short, devote at least 17 percent of their time to ferreting out bottom-dwelling fish using these beak-borne prods. “It turns out the brainiacs of the marine world can also be tool-using workaholics, spending more time hunting with tools than any nonhuman animal,” Mann says. Chimpanzees and other nonhuman primates spend a small amount of time using tools. One population of woodpecker finches spends an estimated 10 percent of its time using twigs and cactus spines to pry insects and spiders out of tree holes. © Society for Science & the Public 2000 - 2008

Keyword: Evolution
Link ID: 12369 - Posted: 06.24.2010

By Bruce Bower The brain saves face similarly in chimpanzees and people, and possibly in macaque monkeys as well. Chimps recognize their compatriots’ faces by utilizing many of the same brain regions that have already been linked to people’s ability to identify familiar faces, a new study suggests. Neural regions that enable efficient discrimination of one individual’s face from another’s may have evolved between 8 million and 6 million years ago in a common ancestor of chimps and humans, propose psychobiologist Lisa Parr of Emory University in Atlanta and her colleagues. Similar neural elements of face discrimination also appear in macaques, another study finds, suggesting that this ability evolved even earlier. Parr’s group has already conducted studies indicating that chimps recognize other chimps’ faces nearly as well as people recognize other people’s faces. “For the most part, similar brain regions are responsible for this ability in chimps and humans,” Parr says. In her work, macaques’ proficiency at face recognition falls short of that displayed by chimps. Parr’s new brain-scan investigation, published online December 18 in Current Biology, comes on the heels of evidence that a closer link exists between face-responsive parts of macaque and human brains than was previously suspected. Part of the brain known as the temporal lobe hosts a handful of face-sensitive regions in macaques and people, according to a team led by neuroscientist Doris Tsao of the University of Bremen in Germany. Parr’s group also found largely temporal-lobe responses in chimps. © Society for Science & the Public 2000 - 2008

Keyword: Miscellaneous
Link ID: 12368 - Posted: 06.24.2010

JUDGES in the US are waking up to the potential misuse of brain-scanning technologies. Last month, Judge John Kennedy of the New Jersey Judiciary rallied 50 of his peers to discuss protecting courts from junk neuroscience. In September, an Indian court jailed a murder suspect for life, partly on the basis of a brain scan. Meanwhile Cephos of Tyngsboro, Massachusetts, is one of several US companies that claim to be able to show whether someone is lying using a functional MRI brain scan. Ethical issues aside, many neuroscientists say the scans have not been tested rigorously enough to be admitted in court, and that they could produce false positives. Now judges are coming to the same conclusion. Kennedy's gathering, at the New Jersey Judicial College in Teaneck, agreed that brain scans, if accompanied by the opinion of a medical professional, can reveal if a person is in pain or mentally competent to stand trial, but cannot be used to determine a state of guilt. Scans can reveal if a person is in pain or mentally competent to stand trial, but not guilt No judge in the US has yet accepted fMRI scans in a trial, but Kennedy expects attempts to admit them to increase. "We're taking a peek over the horizon to see what's coming," he says. Such considerations are spurred in part by the "Daubert standard" - a Supreme Court ruling that extended a judge's authority to challenge the credibility of scientific evidence in court. © Copyright Reed Business Information Ltd

Keyword: Brain imaging; Stress
Link ID: 12367 - Posted: 06.24.2010

Led Zeppelin's immortal song Dazed and Confused might well have been a clinical observation on the state of their audience's brains, say Australian researchers who have found over-enthusiastic head-banging can cause mild brain injury. In a study published in this week's Christmas issue of the British Medical Journal, two University of New South Wales (UNSW) researchers concluded that head-banging to a typical heavy metal tempo could cause mild traumatic brain injury or concussion, and neck injury, particularly as the tempo of the music and angle of movement increased. "Clearly it's a serious issue," says Prof. Andrew McIntosh, co-author and professor of biomechanics at UNSW. "If you observe people after concerts, they clearly look dazed, confused and incoherent, so something must be going on and we wanted to look into it." Beats per minute After careful observation of the behaviour of heavy metal concert-goers, McIntosh and honours student Declan Patton constructed a theoretical head-banging model to better understand the mechanics of the practice. They also spoke to a focus group of local musicians to identify 10 popular songs to head-bang to. © CBC 2008

Keyword: Brain Injury/Concussion
Link ID: 12366 - Posted: 06.24.2010

By Amy Norton NEW YORK (Reuters Health) - Older adults might want to take an interest in their grandchildren's' video games, if early research on the brain benefits of gaming is correct. In a study of 40 adults in their 60s and 70s, researchers found that those who learned to play a strategy-heavy video game improved their scores on a number of tests of cognitive function. Men and women who trained in the game for about a month showed gains in tests of memory, reasoning and the ability to "multi-task." The findings suggest that video games that keep players "on their toes" might help older adults keep their brains sharp, the researchers report in the journal Psychology and Aging. This is the first published study to suggest as much, so it's important not to overstate the findings, said senior researcher Dr. Arthur F. Kramer, a professor of psychology at the University of Illinois at Urbana-Champaign. Still, he told Reuters Health, the results are "very promising," as they suggest that strategy-based video games can enhance reasoning, memory and other cognitive abilities that often decline with age. © 2008 Reuters

Keyword: Alzheimers; Learning & Memory
Link ID: 12365 - Posted: 06.24.2010

By Coco Ballantyne A little over a year ago, a 25-year-old woman visited University Hospital Birmingham in England complaining of frequent 10-second bouts of nausea and lightheadedness, which was sometimes so intense it caused her to pass out. "She was very thin, she was pale, a very sensible young woman," says Una Martin, a clinical pharmacologist at the hospital assigned to the case shortly after the woman's first visit. She had no history of smoking, heavy drinking or psychiatric disorders. Strangely, her fainting episodes coincided with eating sandwiches and drinking fizzy beverages. By the time Martin saw her, the woman had been bounced from one physician to the next and hospitalized twice, once in 2001 and once in 2007—but her condition remained a mystery. "She felt she had been passed from doctor to doctor [and] was beginning to feel it was all in her head," Martin says. Some of the physicians she had visited thought she was suffering from petit mal seizures—brief epileptic brain episodes characterized by loss of consciousness but without the violent shaking associated with the larger grand mal seizures. Yet neurological tests showed no evidence of epilepsy. Martin suspected there might be something wrong with the patient's heart, so she sent her patient home with an external loop electrocardiogram recorder, a device worn on the wrist or waist to monitor heart rhythm for extended periods of time. Whenever the young woman felt lightheaded, she would press a button on the device, causing it to record one to two minutes of heart activity. After monitoring her heart for a week, the woman returned the device to Martin who interpreted the results. © 1996-2008 Scientific American Inc.

Keyword: Miscellaneous
Link ID: 12364 - Posted: 06.24.2010