By Lisa M. Krieger Physicists from the University of California-Santa Cruz have built a tool that studies how the eye processes the busy world around it, transforming the chaos of incoming light into elegantly moving images. The tiny device, which detects patterns of signals sent from the eye to the brain, could someday be used to help design retinal prosthetic devices - or even artificial vision. "We're able to see patterns of electrical activity in a large population of neurons," said Alan Litke of the Santa Cruz Institute for Particle Physics at UCSC. "There could be applications of this technology to many different areas of neuroscience." As described in today's issue of the weekly Journal of Neuroscience, the tool helps explain why seeing is believing. Eyes are exquisite interpreters of light, able to extract life-saving information from a mere pattern of rays - such as whether an oncoming truck is about to flatten you, or has slowed down to allow you to cross safely. Upon absorbing a single particle of light, or photon, retina cells fire off an electrical signal to the brain via the optic nerve. As few as six of these photon signals are required for the brain to perceive a flash. But how does the retina convert light into messages to the brain? Copyright 2007 San Jose Mercury News

Keyword: Vision; Robotics
Link ID: 10835 - Posted: 10.11.2007

Research into the brain's response to speech when under sedation has revealed reduced activity in areas critical for memory and understanding language. Cambridge University scientists used brain imaging to find evidence which may influence the amount of anaesthetic given to patients undergoing surgery. It may also affect attitudes to patients in a coma or vegetative state. Researchers said: "The brain processes speech when sedated but it appears not to fully comprehend or remember it." Using a scanning technique called functional magnetic resonance imaging (fMRI) that registers brain activity, Dr Matt Davis, a cognitive neuroscientist at Cambridge University, and his colleagues mapped speech-related brain activity in volunteers at varying levels of sedation. Their aim was to show how the brain's response to speech changed as people became more sedated and whether understanding of speech might continue even while consciousness and memory were impaired. Professor David Menon, professor of anaesthesia at the University of Cambridge, said the research has important parallels in two clinical situations. "A small proportion of anaesthetised patients report memories of events that occurred in the operating theatre, implying an inadvertent return of consciousness. It is possible that even more patients may have some awareness of events during anaesthesia, but this may fail to be detected because patients have no memories of the event afterwards. (C)BBC

Keyword: Miscellaneous
Link ID: 10834 - Posted: 10.10.2007

US scientists have repaired the nerve damage caused by multiple sclerosis in lab experiments on mice. The team, from the Mayo Clinic in Rochester, hope their work will eventually lead to new treatments. MS is caused by a defect in the body's immune system, which turns in on itself, and attacks the fatty myelin sheath which coats the nerves. The researchers used a human antibody to re-grow myelin in mice with the progressive form of MS. They told a meeting of the American Neurological Association they hope to begin patient trials after perfecting the technique further in animal tests. MS affects around 85,000 people in the UK. Damage to the myelin coating undermines the ability of the nerves to work properly, leading to symptoms including blurred vision, loss of balance and, in some cases paralysis. Although the symptoms can be managed to some degree, there is currently no way to restore damaged myelin. Researcher Dr Moses Rodriguez said: "The concept of using natural human antibodies to treat disease of this kind has not yet been tested in humans, but these research findings are very promising". His colleague Dr Arthur Warrington said: "The findings could eventually lead to new treatments that could limit permanent disability". Myelin repair normally occurs in the body spontaneously, but MS appears to sabotage this mechanism. (C)BBC

Keyword: Multiple Sclerosis
Link ID: 10833 - Posted: 10.10.2007

By JOHN TIERNEY In 1988, the surgeon general, C. Everett Koop, proclaimed ice cream to a be public-health menace right up there with cigarettes. Alluding to his office’s famous 1964 report on the perils of smoking, Dr. Koop announced that the American diet was a problem of “comparable” magnitude, chiefly because of the high-fat foods that were causing coronary heart disease and other deadly ailments. He introduced his report with these words: “The depth of the science base underlying its findings is even more impressive than that for tobacco and health in 1964.” That was a ludicrous statement, as Gary Taubes demonstrates in his new book meticulously debunking diet myths, “Good Calories, Bad Calories” (Knopf, 2007). The notion that fatty foods shorten your life began as a hypothesis based on dubious assumptions and data; when scientists tried to confirm it they failed repeatedly. The evidence against Häagen-Dazs was nothing like the evidence against Marlboros. It may seem bizarre that a surgeon general could go so wrong. After all, wasn’t it his job to express the scientific consensus? But that was the problem. Dr. Koop was expressing the consensus. He, like the architects of the federal “food pyramid” telling Americans what to eat, went wrong by listening to everyone else. He was caught in what social scientists call a cascade. Copyright 2007 The New York Times Company

Keyword: Obesity
Link ID: 10832 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — Ever wonder what your dog does when you aren't around? The answer might surprise you, suggests a new study that found our canine companions behave more logically in our absence. People exert a strong influence on canine choices, it seems, and not always for the better. Dogs are so attuned to our actions, in fact, that they will sometimes abandon logic entirely to please us. But abandoning reason for obedience may serve our pets well in the end. "I do not think that domestication made dogs less intelligent," lead author Anes Erdohegyi told Discovery News. "On the contrary, dogs seem to show special sophistication in understanding social situations." "However," she added, "it is true that focusing on the human...sometimes leads to erroneous behavior." Erdohegyi is a researcher in the Department of Ethology at Budapest's Eotvos Lorand University. She and her colleagues recruited 42 adult pet dogs and their owners for the study, which has been accepted for publication in the journal Animal Behavior. The only criterion for selection was that the dogs had to be "highly motivated to play with a toy." © 2007 Discovery Communications

Keyword: Evolution
Link ID: 10831 - Posted: 06.24.2010

Roxanne Khamsi The reason why even professional basketball and soccer players sometimes miss an easy shot may be partly explained by spontaneous fluctuations of electrical activity within the brain, a study suggests. An experiment conducted by researchers at Washington University, in Missouri, US, found that fluctuations in brain activity caused volunteers to subconsciously exert slightly less physical force when pressing a button on cue. Crucially, this activity is independent of any external stimulus and does not appear related to attention or anticipation. The scientists involved say it is the first direct evidence that internal instabilities – so-called "spontaneous brain activity" – may play an important role in the variability of human behaviour. From the mid-1990s onwards, brain-scanning techniques have revealed variable brain activity that appears unrelated to external stimuli and occurs even when a person is asleep or anaesthetized. But just how such fluctuations in neuronal firings may influence physical behaviour has proven different to untangle. To explore the issue, Michael Fox at Washington University and colleagues designed an experiment that involved monitoring volunteers' brains using functional magnetic resonance imaging (fMRI) as they performed a simple finger-tapping task. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging
Link ID: 10830 - Posted: 06.24.2010

By TARA PARKER-POPE Doctors are writing a new prescription for menopause: the antidepressant. It’s not that all menopausal women are depressed. Instead, the antidepressant has emerged as the drug of choice among women searching for new ways to cool the hot flash. There is no way to track how often antidepressants are prescribed to treat hot flashes, the unpredictable, sticky wave of heat that for many women is the defining symptom of menopause. None are specifically approved for hot flashes, and doctors who prescribe them are doing so “off label.” Menopause researchers say antidepressant use is becoming increasingly common as both women and doctors seek alternatives to menopause hormones. The use of hormone drugs has fallen precipitously since 2002, when a government study linked hormone use in older women to stroke and breast cancer. It isn’t clear why antidepressants seem to cool hot flashes, at least in some women. The link was made by chance in studies of women with breast cancer. Some cancer drugs set off hot flashes, and researchers noticed that women who were also taking the antidepressants known as a selective serotonin reuptake inhibitors had fewer flashes. Studies looking at the use of these and other serotonin-altering drugs to treat hot flashes in healthy menopausal women have been disappointing. Two, Wyeth’s Effexor and GlaxoSmithKline’s Paxil, have shown a meaningful benefit in high-quality controlled studies, according to a review published last year in The Journal of the American Medical Association. Copyright 2007 The New York Times Company

Keyword: Hormones & Behavior; Depression
Link ID: 10829 - Posted: 06.24.2010

By NICHOLAS WADE Royal is a cantankerous old male baboon whose troop of some 80 members lives in the Moremi Game Reserve in Botswana. A perplexing event is about to disturb his day. From the bushes to his right, he hears a staccato whoop, the distinctive call that female baboons always make after mating. He recognizes the voice as that of Jackalberry, the current consort of Cassius, a male who outranks Royal in the strict hierarchy of male baboons. No hope of sex today. But then, surprisingly, he hears Cassius’s signature greeting grunt to his left. His puzzlement is plain on the video made of his reaction. You can almost see the wheels turn slowly in his head: “Jackalberry here, but Cassius over there. Hmm, Jackalberry must be hooking up with some one else. But that means Cassius has left her unguarded. Say what — this is my big chance!” The video shows him loping off in the direction of Jackalberry’s whoop. But all that he will find is the loudspeaker from which researchers have played Jackalberry’s recorded call. Copyright 2007 The New York Times Company

Keyword: Evolution
Link ID: 10828 - Posted: 06.24.2010

By Sandra G. Boodman An avid hockey player since age 6, Lucio "Lou" Battista is no stranger to pain. "He has a very high tolerance," his mother, Liz Battista, said of her only child. Last year while playing defense for his roller hockey team, Lou, then 15, was body-slammed from behind and hurled chest first into the board that separates the rink from spectators, then played two more games before realizing something was wrong. The blow was so forceful it fractured the hyoid bone in his neck, tore his esophagus and forced air into the space in the chest between his lungs, endangering his heart. He spent five days in the hospital and has fully recovered from injuries that could have been fatal. But that experience, he said, paled in comparison with his ordeal last May, when he developed eye pain so searing it literally made him weep. "It was unbearable," recalled Lou, a high school senior in Hopewell Junction, N.Y., who will turn 17 in two weeks. Unlike the hockey injuries, which were diagnosed quickly, it took doctors a week to figure out the reason for the stabbing pain and why his left eye went from 20/20 vision to being legally blind in a matter of days. His doctors were baffled in part because an array of sophisticated tests -- CT scans, MRIs, a spinal tap and extensive blood work -- were all normal. It was a pediatric neurologist, the second he had seen, who quickly diagnosed the problem and within hours initiated treatment that stopped the pain and restored his sight. © 2007 The Washington Post Company

Keyword: Vision
Link ID: 10827 - Posted: 06.24.2010

By Sandra G. Boodman The titles lure aspirational parents eager to do what's best for their infants: Baby Einstein, Baby Galileo, Baby Shakespeare and even Brainy Baby with its original motto, "a little genius in the making." But do these enormously popular and profitable videos and DVDs devised for viewers too young even to sit up provide educational enrichment, as supporters contend? Or are they a skillful marketing scheme for products that may actually impede cognitive development, as critics say? Those questions have been reignited by a highly publicized study by veteran child development researchers at the University of Washington. The Seattle team surveyed more than 1,000 families in February 2006 and found that infants between 8 and 16 months who regularly watched Baby Einstein and Brainy Baby videos knew substantially fewer words -- six to eight out of 90 -- than infants who did not watch them, according to parental reports. The deficit, which increased with each hour of video viewing, was not seen among babies who watched other programming, such as "Sesame Street" or "SpongeBob SquarePants" or adult shows such as "Oprah." © 2007 The Washington Post Company

Keyword: Development of the Brain; Intelligence
Link ID: 10826 - Posted: 06.24.2010

Charles Glatt For centuries, philosophers, theologians and biologists have debated the relative roles of inborn traits versus environmentally defined experiences in determining what and who we are. This nature-nurture debate carries fundamental implications for our understanding of self-determination, or free will. Indeed, as research has begun to identify genetic risk factors for certain behavioral traits, these risk factors have already been used in court (see here and here)to argue that punishment should be lessened for convicted felons -- the presumption being that their genes made them inherently more likely to misbehave. The importance and challenge of the nature-nurture debate in behavior has recently spawned a new area of research that looks at the interaction between genetic risk factors and experience in the development of psychopathology. A study led by Joan Kaufman and Joel Gelernter, both of Yale, and published in Biological Psychiatry, has demonstrated what many of us have intuitively concluded, which is that both nature and nurture contribute to who we are. In this particular study, genetic and environmental factors interact to determine risk for depression. In their study, "Brain-Derived Neurotrophic Factor-5-HTTLPR Gene Interactions and Environmental Modifiers of Depression in Children," Kaufman, Gelernter and colleagues found distinct gene-environment interactions in the risk for depressive symptoms. Other studies have found similar interactions, but looked mainly at interactions between single genetic and single environmental risk factors. This study ups the ante by examining various interactions among two genetic and two environmental factors, including a four-way interaction with two genetic and two environmental variables. © 1996-2007 Scientific American, Inc.

Keyword: Depression; Genes & Behavior
Link ID: 10825 - Posted: 06.24.2010

Michael Hopkin Next time you whisper sweet nothings to the object of your affections as they peacefully doze off, don't be surprised if they can't remember a word of it the next morning. Neuroscientists have shown that the brain's pathways for deciphering speech, and forming memories of it, switch off as anaesthetized patients begin to nod off. They suspect the same holds true for normal, non-drug-induced sleep. Researchers led by Matt Davis of the Medical Research Council Cognition and Brain Sciences Unit in Cambridge, UK, studied 12 volunteers under the influence of varying amounts of an anaesthetic called propofol, which induced varying levels of drowsiness. They played them recordings of speech or other sounds, and monitored their brains using a technique called functional magnetic resonance imaging. The volunteers' brains were more active in response to speech than to generic noise, suggesting that they still recognised spoken words. But the part of the brain involved with the more subtle job of untangling words that can have alternative meanings depending on context or spelling (such as 'bark', or 'pear/pair') showed no activity in the drowsiest volunteers. Neither did the part involved with forming memories of speech. © 2007 Nature Publishing Group

Keyword: Learning & Memory; Sleep
Link ID: 10824 - Posted: 06.24.2010

By MICHELE MORGAN BOLTON MIDDLEBOROUGH, Mass., — The big news in this struggling southeastern Massachusetts community is a proposed $1 billion casino complex that many hope will bring financial salvation. But for a small group of residents, the hope for economic revival is overshadowed by health concerns. They are awaiting a report later this year that could reveal whether the dozens of cases of Lou Gehrig’s disease centered around a downtown industrial area were caused by pollution. The cases, which both state and federal officials call a disease cluster, are located within a mile of Everett Square — a densely settled neighborhood adjacent to the town’s onetime factory row. It is now home to two Superfund sites. The study, which was financed by the federal Agency for Toxic Substances and Disease Registry and conducted by state health scientists, will be followed by the creation of a statewide registry to track cases of the disease, formally known as amyotrophic lateral sclerosis, the cause of which is not fully understood. State Senator Marian Walsh, a Democrat from West Roxbury, said it was understandable that most residents were more interested in the prospect of obtaining a casino, which would be built by the Mashpee Wampanoag Indians and is expected to create as many as 10,000 jobs. “It’s human nature that we move toward pleasure and away from pain,” Ms. Walsh said. “But here, if we can understand the genesis, the registry will bring in money, information and resources that will help get to a cure.” Copyright 2007 The New York Times Company

Keyword: ALS-Lou Gehrig's Disease ; Neurotoxins
Link ID: 10823 - Posted: 06.24.2010

The Canadian Press Female students who leave home to attend first-year university or college are significantly more likely to start binge eating than peers who stay home to attend school — a behaviour that puts them at risk for more serious eating disorders in the future, new research suggests. A study of University of Alberta students found that females in their inaugural year were three times more likely to binge eat if they had left their parents' home to obtain post-secondary education. Repeated bouts of eating large amounts of food at a single sitting can also pack on the pounds over time, setting the stage for obesity, diabetes and other health problems, says the study. (CBC) As well, female students who reported higher levels of dissatisfaction with their bodies had a three-fold greater risk of binge eating episodes, say the researchers, whose study is published in the October issue of the Journal of Youth and Adolescence. Lead researcher Erin Barker, who earned her PhD in developmental psychology at the Edmonton-based university, said young women who scored low on social adjustment also were more apt to binge eat. © The Canadian Press, 2007

Keyword: Anorexia & Bulimia
Link ID: 10822 - Posted: 06.24.2010

By ALEX BERENSON Eli Lilly yesterday added strong warnings to the label of Zyprexa, its best-selling medicine for schizophrenia, citing the drug’s tendency to cause weight gain, high blood sugar, high cholesterol and other metabolic problems. For the first time, Zyprexa’s label now acknowledges that the drug causes high blood sugar more than some other medicines for schizophrenia and bipolar disorder, called atypical antipsychotics. Lilly previously argued that Zyprexa had not been proved to cause high blood sugar at a more frequent rate than its competitors. Concern about Zyprexa’s side effects has been increasing since at least 2004, and Zyprexa’s prescriptions and market share have fallen sharply over the period. As a result, the new warnings may have only a moderate impact among doctors and patients, said S. Nassir Ghaemi, director of the Bipolar Disorder Research Program at Emory University. “The knowledge has been out there, and it’s already impacted prescribing patterns a great deal,” Dr. Ghaemi said. The new label will also indicate that patients who take Zyprexa may keep gaining weight for as long as two years after starting therapy. That contradicts earlier public statements by Lilly that weight gain on Zyprexa tends to plateau after a few months of use. One in six patients who take Zyprexa will gain more than 33 pounds after two years of use, the label says. Copyright 2007 The New York Times Company

Keyword: Schizophrenia
Link ID: 10821 - Posted: 06.24.2010

DALLAS - Fertility rates in birds can get a lift if the male anticipates that a sexual encounter is just around the corner, researchers from the University of Texas reported on Thursday. The unorthodox study involved 28 male quails, 14 female quails, and two chambers: a green one near a noisy room and a white one on an isolated table. The males were put into each of the chambers for a brief period daily over a period of five days. Half were given access to a female immediately after their time in the green chamber but not the white: for the other half it was the opposite. The male quails therefore came to associate one chamber with the act of copulation. "We can take anything and make it a romantic setting if there is the anticipation of sex," said Michael Domjan, a psychology professor at the University of Texas at Austin. "We concluded the experiment by pairing the males with single females. One male would go into the romantic chamber and then have access to the female, then one would go into the non-romantic chamber and then have access to the same female," Domjan, one of the authors of the study, told Reuters by telephone. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Sexual Behavior
Link ID: 10820 - Posted: 06.24.2010

By Constance Holden In a particularly stimulating study, researchers have found that lap dancers--women who work in strip joints and, for cash, gyrate in the laps of seated men--earn more when they are in the fertile phase of their menstrual cycle. The finding suggests that women subtly signal when they are most fertile, although just how they do it is not clear. Women, unlike many mammals, don't come into heat or estrus, a state of obvious fertility that attracts potential mates. Common wisdom has it that estrus was lost as humans evolved. The notion is that women evolved "concealed ovulation" along with around-the-month sexual receptivity the better to manipulate males by keeping them in the dark, says Geoffrey Miller, an evolutionary psychologist at the University of New Mexico in Albuquerque. But now Miller and colleagues have found evidence that a woman’s state of fertility may not be so secret after all. The researchers used ads and flyers to sign up 18 lap dancers from local clubs. Each woman was asked to log on to a Web site and report her work hours, tips, and when she was menstruating. Lap dancers generally work 5-hour shifts with 18 or so 3-minute performances per shift. They average about $14 per "dance"--all of which is called a "tip" because it is illegal to pay for sex in New Mexico. © 2007 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 10819 - Posted: 06.24.2010

Bruce Bower Two gene variations appear frequently in depressed patients who contemplate killing themselves during treatment with a common antidepressant medication, a new study finds. In the study, reports of suicidal thoughts occurred from 2 to 15 times as often in antidepressant-treated patients with the key gene variations as in patients without them, say psychiatrist Gonzalo Laje of the National Institute of Mental Health in Bethesda, Md., and his colleagues. Participants received citalopram, a widely prescribed antidepressant related to medications such as fluoxetine (Prozac). "These findings need to be replicated before we can devise a genetic test to determine who's at risk for suicidal thoughts during antidepressant treatment," Laje says. The study identifies two crucial genes that contribute to the formation of cell receptors for glutamate, a chemical messenger in the brain that has been implicated in antidepressant effects. Variants of these genes apparently promote suicidal thinking only in depressed people taking antidepressants, the researchers conclude in the October American Journal of Psychiatry. ©2007 Science Service.

Keyword: Depression; Genes & Behavior
Link ID: 10818 - Posted: 06.24.2010

By Elizabeth Quill Carbon dioxide may deserve blame for more than just the panic over global warming. New research involving healthy people inhaling the gas indicates that the brain's reaction to carbon dioxide helps explain panic attacks and other anxious feelings, independent of rising world temperatures. This new insight, reported 3 October in PLoS One, could help physicians prevent the development of depression and other anxiety disorders. It's long been known that anxiety-prone individuals often experience panic attacks when they breathe in carbon dioxide. Psychiatrists have theorized that emotional distress reflects a built-in response to suffocation. The "false suffocation alarm theory" suggests that the brain has a carbon dioxide sensor and that it is oversensitive in some people, mistakenly spurring panic attacks. Such a sensor could have evolved to alert oxygen-breathing organisms of impending death. Eric Griez, an experimental psychiatrist at the University of Maastricht, the Netherlands, came up with a test for the false-alarm theory. If it is valid, he surmised, healthy individuals should show some sensitivity to carbon dioxide as well. So he and his colleagues recently asked 64 volunteers to inhale two deep breaths of four mixtures of compressed air containing 9%, 17.5%, 35%, or no carbon dioxide. After inhaling each mixture, the volunteers continuously rated their level of fear and discomfort on a scale from 1 to 100 using a touch screen and rated their panic using a questionnaire that listed 13 common symptoms of panic attacks. As the dose of carbon dioxide increased, so did fear and discomfort. © 2007 American Association for the Advancement of Science.

Keyword: Stress
Link ID: 10817 - Posted: 06.24.2010

Scientists are hopeful that they have found a way to halt the progression of motor neurone disease (MND). A team at Bath University discovered a causal link between the gene involved in the formation of blood vessels and the development of some forms of MND. Mutant versions of the gene's product - angiogenin - are toxic to motor neurones, so blocking this process may stop the disease, they say. The latest UK work is published in the journal Human Molecular Genetics. There are about 5,000 people suffering with MND at any one time in the UK. The condition affects men more than women and one or two people in every 100,000 will be newly diagnosed with MND each year. In MND, over time, the cells responsible for transmitting the chemical messages that enable muscle movements become injured and subsequently die. Ultimately, the disease fatally interferes with those muscles involved in breathing. Last year, scientists discovered that some patients with MND have a mutated version of the human angiogenin gene. Since then, experts have been trying to find out what role angiogenin plays in the maintenance and development of motor neurones. Lead researcher Dr Vasanta Subramanian said: "We have found that mutated versions of this molecule are toxic to motor neurones and affect their ability to put out extensions called the axons. (C)BBC

Keyword: ALS-Lou Gehrig's Disease
Link ID: 10816 - Posted: 10.05.2007