by Rachel Nowak INFRARED light can stimulate neurons in the inner ear as precisely as sound waves, a discovery that could lead to better cochlear implants for deaf people. A healthy inner ear uses hair cells that respond to sound to stimulate neurons that send signals to the brain. But hair cells can be destroyed by disease or injury, or can contain defects at birth, leading to deafness. In such cases, cochlear implants can directly stimulate neurons. The hearing provided by today's implants is good enough to enable deaf children to develop speech skills that are remarkably similar to hearing children's. Implant users still find it tough to appreciate music, communicate in a noisy environment and understand tonal languages like Mandarin, however. That's because the implants use only 20 or so electrodes, a small number compared to the 3000-odd hair cells in a healthy ear. More sources of stimulation should make hearing clearer but more electrodes cannot be packed in because tissue conducts electricity, so signals from different electrodes would interfere. In contrast, laser light targets nerves more precisely and doesn't spread, which could allow an implant to transmit more information to the neurons. © Copyright Reed Business Information Ltd.

Keyword: Hearing
Link ID: 12256 - Posted: 06.24.2010

By Alan Mozes (HealthDay News) -- A compound that boosts growth hormone levels in Alzheimer's patients may not slow the disease, new research suggests. The study, funded by drug giant Merck, was spurred by promising animal research that had suggested that the compound, called MK-677, might help curb Alzheimer's effect on the brain. However, "the study suggests that targeting this hormone system may not be an effective approach at slowing the rate of Alzheimer's disease progression," said study author Dr. J.J. Sevigny, associate director of clinical neuroscience at Merck Research Laboratories in North Wales, Pa. His team reported its finding in the Nov. 18 issue of Neurology. ad_icon "In a similar vein, the study challenges a commonly held theory that hormones may attack beta-amyloid plaque in the brain," Sevigny added. "That was the premise of this research: that by giving this medication we'd be able to influence the beta-amyloid in the brain. And we didn't receive this result in this study." Based on the findings, Merck has now stopped investigating MK-677 for use against Alzheimer's. SOURCES: J.J. (Jeffrey) Sevigny, M.D, associate director, clinical neuro-science, Merck Research Laboratories, North Wales, Pa.; Maria Carrillo, Ph.D., director, medical & scientific relations, Alzheimer's Association, National Office, Chicago; Nov. 18, 2008, Neurology © 2008 Scout News LLC.

Keyword: Alzheimers; Hormones & Behavior
Link ID: 12255 - Posted: 06.24.2010

By GARDINER HARRIS WASHINGTON — Powerful antipsychotic medicines are being used far too cavalierly in children, and federal drug regulators must do more to warn doctors of their substantial risks, a panel of federal drug experts said Tuesday. More than 389,000 children and teenagers were treated last year with Risperdal, one of five popular medicines known as atypical antipsychotics. Of those patients, 240,000 were 12 or younger, according to data presented to the committee. In many cases, the drug was prescribed to treat attention deficit disorders. But Risperdal is not approved for attention deficit problems, and its risks — which include substantial weight gain, metabolic disorders and muscular tics that can be permanent — are too profound to justify its use in treating such disorders, panel members said. “This committee is frustrated,” said Dr. Leon Dure, a pediatric neurologist from the University of Alabama School of Medicine who was on the panel. “And we need to find a way to accommodate this concern of ours.” The meeting on Tuesday was scheduled to be a routine review of the pediatric safety of Risperdal and Zyprexa, popular antipsychotic medicines made, respectively, by Johnson & Johnson and Eli Lilly & Company. Food and Drug Administration officials proposed that the committee endorse the agency’s routine monitoring of the safety of the medicines in children and support its previous efforts to highlight the drugs’ risks. Copyright 2008 The New York Times Company

Keyword: Schizophrenia; Development of the Brain
Link ID: 12254 - Posted: 06.24.2010

Hustling up the escalator, I didn't have time to appreciate the irony of my situation: I was running late to a session on stress. It was with more than strictly professional interest then, that I settled in to hear 5 researchers discuss their latest findings on stress and the brain. In some ways, stress is all in our heads, said Bruce McEwen, a neuroendocrinologist at Rockefeller University in New York City, since our brains are responsible for recognizing and responding to stressors. Three sections in particular: the amygdale, the hippocampus, and the prefrontal cortex work with the hypothalamus to flip on (and hopefully shut down) production of stress hormones and other automatic responses to stress, like increased heart rate. But researchers are now learning how stressors can physically alter our brains, which in turn, may impact how we learn, form memories, and even make decisions. The effects are sometimes reversible but sometimes not, the scientists reported. Stress the monkey. Simona Spinelli of the National Institutes of Health in Bethesda, Maryland and colleagues placed 13 young monkeys in the care of their peers for 6 months, while another 15 monkeys spent the same time with their mothers. Both sets of monkeys then rejoined typical social groups, and the researchers scanned their brains after several months of exposure to the normal environment. The monkeys raised under Lord of the Flies-like conditions showed enlarged brain regions in areas related to stress, compared to the control group, even after spending time in the normal environment. This suggests that early stress can have long-lasting impacts on the brain, Spinelli says, though follow-up studies in humans are necessary. © 2008 American Association for the Advancement of Science.

Keyword: Stress
Link ID: 12253 - Posted: 06.24.2010

By Christof Koch What is consciousness? What is this ineffable, subjective stuff—this thing, substance, process, energy, soul, whatever—that you experience as the sounds and sights of life, as pain or as pleasure, as anger or as the nagging feeling at the back of your head that maybe you’re not meant for this job after all. The question of the nature of consciousness is at the heart of the ancient mind-body problem. How does subjective consciousness relate to the objective universe, to matter and energy? Consciousness is the only way we experience the world. Without it, you would be like a sleepwalker in a deep, dreamless sleep, acting in the world, speaking, having babies, but without feeling anything. You would feel nothing, nada, nichts, rien. Indeed, in the most famous deduction of Western thought, philosopher and mathematician René Descartes concluded that because he was conscious he existed. That was his only unassailable proof that he wasn’t just a chimera. Maybe he didn’t have the body he thought he had, maybe he had fake memories (premonitions of The Matrix), but because he was conscious he must exist. Yet the questions go on. Are only people conscious? What about a fetus? What about a neurological patient in a persistent vegetative state, such as Terri Schiavo (who died in 2005), who can’t do much more than open and close her eyes? Although many are willing to accord sentience, consciousness, to our beloved cats and dogs, what about apes, monkeys, whales, mice, bees and all the other critters on the planet? Can a fly be conscious? What about artificial consciousness? Is your cool iPhone sentient? Can machines ever become conscious, as is widely assumed in so many science-fiction novels and movies? © 1996-2008 Scientific American Inc.

Keyword: Attention; Emotions
Link ID: 12252 - Posted: 06.24.2010

By Susana Martinez-Conde and Stephen L. Macknik Scientists did not invent the vast majority of visual illusions. Rather, they are the work of visual artists, who have used their insights into the workings of the visual system to create visual illusions in their pieces of art. We have previously pointed out in our essays that, long before visual science existed as a formal discipline, artists had devised techniques to “trick” the brain into thinking that a flat canvas was three-dimensional, or that a series of brushstrokes in a still life was in fact a bowl of luscious fruit. Thus the visual arts have sometimes preceded the visual sciences in the discovery of fundamental vision principles, through the application of methodical—although perhaps more intuitive—research techniques. In this sense, art, illusions and visual science have always been implicitly linked. It was only with the birth of the op art (for “optic art”) movement that visual illusions became a recognized art form. The movement arose simultaneously in Europe and the U.S. in the 1960s, and in 1964 Time magazine coined the term “op art.” This style became hugely popular after the Museum of Modern Art in 1965 held an exhibition called “The Responsive Eye.” In it, op artists explored many aspects of visual perception, such as the relations between geometrical shapes, variations on “impossible” figures that could not occur in reality, and illusions concerning brightness, color and shape perception. But “kinetic,” or motion, illusions drew particular interest. In these eye trick, stationary patterns give rise to the powerful but subjective perception of (illusory) motion. © 1996-2008 Scientific American Inc.

Keyword: Vision
Link ID: 12251 - Posted: 06.24.2010

by David Robson WOMEN may be fed up with being stereotyped as the chattier sex, but the cliche turns out to be true - in female-centric monkey groups at least. The gossipy nature of female macaques also adds weight to the theory that human language evolved to forge social bonds. Many researchers think that language replaced grooming as a less time-consuming way of preserving close bonds in ever-growing societies. Nathalie Greeno and Stuart Semple from Roehampton University in London hypothesised that if this was true then in species of animals with large social networks, such as macaques, vocal exchanges should be just as important as grooming. The duo listened to a group of 16 female and eight male macaques living on Cayo Santiago island off Puerto Rico for three months. They counted the grunts, coos and girneys - friendly chit-chat between two individuals - while ignoring calls specific to the presence of food or a predator. The team found that females made 13 times as many friendly noises as males. "The results suggest that females rely on vocal communication more than males due to their need to maintain the larger social networks," Greeno says. Females rely on vocal communication more than males due to their need to maintain larger social networks © Copyright Reed Business Information Ltd.

Keyword: Language; Evolution
Link ID: 12250 - Posted: 06.24.2010

The dietary supplement Ginkgo biloba was found to be ineffective in reducing the development of dementia and Alzheimer's disease in older people, according to a study published in the Journal of the American Medical Association1. Researchers led by Steven T. DeKosky, M.D., formerly of the University of Pittsburgh, vice president and dean of the School of Medicine at the University of Virginia in Charlottesville, conducted the trial known as the Ginkgo Evaluation of Memory (GEM) study at four clinical sites over the course of 8 years. GEM is the largest clinical trial ever to evaluate ginkgo's effect on the occurrence of dementia. This research was co-funded by five components of the National Institutes of Health (NIH): National Center for Complementary and Alternative Medicine (NCCAM); National Institute on Aging (NIA); National Heart, Lung, and Blood Institute; National Institute of Neurological Disorders and Stroke, and the Office of Dietary Supplements. "We have made enormous progress in understanding the basic mechanisms involved in Alzheimer's disease, and we continue to pursue a vigorous program to translate what we know into the development and testing of new potential therapies for this devastating disease," said Richard Hodes, M.D., director of the NIA. "However, it is disappointing that the dietary supplement tested in this study had no effect in preventing Alzheimer's disease."

Keyword: Alzheimers; Learning & Memory
Link ID: 12249 - Posted: 11.20.2008

-- Biologists on Wednesday explained how the larvae of marine zooplankton can see with just two cells, using what is believed to be the world's simplest vision system. Zooplankton are tiny creatures such as copepods and krill that drift in the ocean's water columns, swimming up from the depths towards the light in order to graze on marine plants called phytoplankton near the surface. This movement, called phototaxis, is the biggest biomass displacement in the world. In a study published by the British-based journal Nature, European scientists looked at the larvae of the marine ragworm Platyneris dumerilii to try to explain how plankton are able to do the phototaxis trick. The larva has just two eye cells, consisting of a pigment cell and a light-sensitive cell, say the investigators. The cells are unable to form images but enable the plankton to sense the difference between light and dark and send appropriate signals to its swimming mechanism, say the investigators. © 2008 Discovery Communications, LLC.

Keyword: Vision; Evolution
Link ID: 12248 - Posted: 06.24.2010

by Ewen Callaway The female brain has a clever way of mitigating the stress experienced during menstruation: it flip-flops. The region of the brain used for coping with stress flips to the opposite side of the brain during a woman's period - from an area linked to negative emotion to one that usually deals with cheerier thoughts. Such a change could help women cope with the hormonal maelstrom going on in their bodies without causing huge behavioural shifts. Oestrogen levels levels, in particular, plummet around menstruation. Jen-Chuen Hsieh, a neuroscientist at National Yang-Ming University in Taipei, Taiwan, and colleagues studied 14 women using a magnetoencephalograph ¬ a machine that measures magnetic waves created by brain activity. All their subjects were right-handed, to ensure that the left-right orientation of their brains matched. When the women were shown frightening images, they normally triggered activity in the right half of the women's brains. This side of the brain tends to process negative feelings, such as anxiety. During the women's menstrual periods, however, the images activated areas in the left half of their brains, which handles positive emotions. © Copyright Reed Business Information Ltd.

Keyword: Stress; Hormones & Behavior
Link ID: 12247 - Posted: 06.24.2010

Scientists have identified a molecule which could be key to understanding the cause of motor neurone disease (MND) and other neurodegenerative disorders. The Proceedings of the National Academy of Sciences study raise the hope of new treatments being developed. The London-based team showed the molecule, Wnt3, plays a key role in establishing connections between nerve cells and the muscles they control. These connections become progressively weaker in MND patients. Without properly-formed connections - or synapses - the muscle cannot receive the nerve signal that tells it to contract. This results in the muscle weakness that is typical of MND. However, scientists have not been clear how synapses are formed in normal circumstances and this has made it very difficult to pin down what goes wrong in MND. The researchers, from University College London and King's College London, identified Wnt3 as key to the process. It assists a second molecule, called Agrin, which co-ordinates construction of the connection - or synapse. Lead researcher Professor Patricia Salinas said: "The work we are publishing today puts an important piece of the puzzle in place and offers up a new possibility for developing drugs to treat MND and other neurodegenerative diseases. "If we can build up a thorough picture to show how synapses are normally formed between nerves and muscles we can start to look for any elements that aren't working properly in people with MND. This might also lead to strategies for nerve repair after an injury." (C)BBC

Keyword: ALS-Lou Gehrig's Disease
Link ID: 12246 - Posted: 11.18.2008

A handful of people reach old age with razor-sharp brains. Scientists call them "super aged." But what makes them special? In a new study, researchers examined the brains of five dead people who were considered super aged because after age 80 they had performed higher on memory tests than others their age. The scientists compared these brains to those from some "normal," non-demented elderly folks who had died. Story continues below ↓advertisement | your ad here The super aged brains had fewer fiber-like tangles than the brains of people who had aged normally. The tangles consist of a protein called tau that accumulates inside brain cells and is thought to eventually kill them, the researchers explained in what they're calling a preliminary finding. Tangles are found in at least moderate numbers in the brains of all elderly people, but they are more prevalent in the brains of Alzheimer's disease patients. "It was always assumed that the accumulation of these tangles is a progressive phenomenon through the aging process. But we are seeing that some individuals are immune to tangle formation and that the presence of these tangles seems to influence cognitive performance," said Changiz Geula, principal investigator of the study and a research professor of neurology at the Cognitive Neurology and Alzheimer's Disease Center at Northwestern's Feinberg School in Illinois. © 2008 LiveScience.com.

Keyword: Alzheimers
Link ID: 12245 - Posted: 06.24.2010

By JOHN TIERNEY Last year, a team of researchers at Harvard made headlines with an experiment testing unconscious bias at hospitals. Doctors were shown the picture of a 50-year-old man — sometimes black, sometimes white — and asked how they would treat him if he arrived at the emergency room with chest pains indicating a possible heart attack. Then the doctors took a computer test intended to reveal unconscious racial bias. The doctors who scored higher on the bias test were less likely than the other doctors to give clot-busting drugs to the black patients, according to the researchers, who suggested addressing the problem by encouraging doctors to test themselves for unconscious bias. The results were hailed by other psychologists as some of the strongest evidence that unconscious bias leads to harmful discrimination. But then two other researchers, Neal Dawson and Hal Arkes, pointed out a curious pattern in the data. Even though most of the doctors registered some antiblack bias, as defined by the researchers, on the whole doctors ended up prescribing the clot-busting drugs to blacks just as often as to whites. The doctors scoring low on bias had a pronounced preference for giving the drugs to blacks, while high-scoring doctors had a relatively small preference for giving the drugs to whites — meaning that the more “biased” doctors actually treated blacks and whites more equally. Copyright 2008 The New York Times Company

Keyword: Emotions
Link ID: 12244 - Posted: 06.24.2010

By BENJAMIN BRODY, M.D “Has anything changed since the treatments began?” I ask the patient, as he lies down on a stretcher in the ECT suite. The anesthesiologist places an IV line in his arm and checks his vital signs. My attending psychiatrist adjusts the machine that delivers the electric stimulus. I’m a psychiatry intern, and this is my electroconvulsive therapy rotation. I’m here to watch and learn. “My cellphone always has a great charge,” the patient deadpans. If this were a friend or colleague, I would laugh easily. But this is a patient I barely know. He has bipolar disorder, a previous suicide attempt and a history of bizarre, impulsive behavior. In that context, his joke just feels inappropriate and overly familiar. I’m taken aback. Is it O.K. to laugh, I wonder? An intern, with years of experience being inexperienced, I quickly glance around to take stock of the room. The nursing assistant laughs and the anesthesiologist grins broadly. The attending psychiatrist remains stone-faced, and says, “Clearly he’s improving.” As the anesthesiologist injects a sedative, a telephone rings. Everyone’s hands are occupied; the ringing continues. Just as the patient starts to drift off, he looks over at me and says: “Can you get that? It might be the governor calling to stay my execution.” Copyright 2008 The New York Times Company

Keyword: Depression; Schizophrenia
Link ID: 12243 - Posted: 06.24.2010

By Jayne Lytel Paging through 176 MRI scans of my 9-year-old's brain on my home computer, I discovered a button that let me play them as a movie. Gray swirls burst onto the screen, dissolving into one another and revealing a new set of patterns. Beams of light faded in and out, some curving and traveling around the different regions of his brain. I saw the squiggly folds of his cerebral cortex, the gray matter that is the center of human intelligence. These scans, the most intimate pictures I had ever seen of my son, Leo, may help researchers understand what's going on in his head -- and relieve him of a diagnosis that I have devoted several years to helping him overcome. Leo, identified as No. C1059, underwent the scans as part of a research study at the Olin Neuropsychiatry Research Center at Hartford Hospital in Connecticut. He was thrilled to earn $200 for taking part. I smiled along with him, because I could remember the days when he had a limited range of emotions, and pride was not one of them. The study is examining 35 children, ranging in age from 8 to 17, who once had an autism-spectrum diagnosis but no longer do. Leo was invited to participate based on how I had described changes in his behavior and communication skills since he was given an autism diagnosis seven years ago. It is one of several studies underway to clarify the experiences of a growing number of children who are apparently emerging from autism and its related disorders to function almost indistinguishably from their peers; it aims to reveal whether it is indeed possible to recover from autism. © 2008 The Washington Post Company

Keyword: Autism
Link ID: 12242 - Posted: 06.24.2010

They say "romantic love" was invented by the troubadors of the Middle Ages. They also say it doesn't last. But Rutgers University anthropologist Helen Fisher and colleagues reported today that functional brain imaging studies show that being "in love" transcends both culture and time. The researchers imaged the brains of 17 young Americans and 17 young Chinese who had been in intense love relationships for 6 months. The team compared how the volunteers' brains reacted to a photograph of a loved one versus a photo of someone they didn't know. When viewing a loved one, the brains of the volunteers registered activity in "several regions associated with addiction," said Fisher--notably in the ventral tegmental area, a region of the brain stem that are rich in receptors for dopamine, the chief actor in the brain's "reward circuit". The team also rounded up 17 people of both sexes, aged 40 to 65, married at least 20 years, who said they were still "in love" with their spouses. The researchers found that the same areas were activated in most of them on viewing a photo of their spouse. But longterm romantic love also stirred up brainstem regions rich in serotonin (see pic) and a chemical called vasopressin, which is associated with monogamy in voles. The upshot is that the long-marrieds have the best of both worlds--they are still in love, but the "the obsession, mania and anxiety" of newly-hatched infatuation "is replaced by calm," said Fisher. © 2008 American Association for the Advancement of Science. All Rights Reserved.

Keyword: Sexual Behavior; Emotions
Link ID: 12241 - Posted: 06.24.2010

Epigenetics has been a hot topic at this year's meeting. When I ducked out of a symposium devoted to it on Saturday afternoon to catch another talk, by the time I got back the room was jam packed and a convention center employee was turning people away. "If the fire marshal comes we'll be in big trouble," she said. There was only slightly more elbow room at this afternoon's press conference, where half a dozen researchers described their recent work investigating the possible roles of epigenetic mechanisms in everything from learning and memory to problems such as obesity, drug addiction and anxiety. In a nutshell, epigenetics means altering gene expression without messing with DNA sequences. It includes DNA methylation, a chemical alteration to DNA that prevents genes from being read out to make proteins, and histone deacetylation, which accomplishes the same thing by keeping DNA strands tightly wound around spool-like histone proteins. Epigenetics has been a growing area of exploration in cancer biology over the last 20 years. Drugs that inhibit histone deacetylation, for example, have shown promise as cancer-fighting drugs. Relatively little is known about the role of epigenetic mechanisms in the brain, but researchers described several intriguing findings at the press conference. Among them: Tracy Bale of the University of Pennsylvania in Philadelphia presented findings suggesting that high-fat diets during pregnancy can increase the body size of subsequent generations via epigenetic mechanisms in mice. © 2008 American Association for the Advancement of Science. All Rights Reserved.

Keyword: Learning & Memory; Genes & Behavior
Link ID: 12240 - Posted: 06.24.2010

Ashley Yeager Scientists whose work came under scrutiny during a political debate about work funded by the US National Institutes of Health (NIH) in Bethesda, Maryland, censored their own later work, a new study has found1. In July 2003, former congressman Patrick Toomey (Republican, Pennsylvania) argued that NIH grants funding studies on certain types of sexual behaviour were less worthy of taxpayer dollars than those on devastating diseases. He proposed an amendment to the 2004 NIH appropriations bill to revoke funding for five grants — four of which examined sexual behaviour. Toomey's amendment was defeated by two votes, but after a congressional investigation later in 2003, NIH director Elias Zerhouni was sent a list of 250 grants by 157 scientists, most of which were for studies on sexual behaviour and drug use. Republicans involved in the investigation said that the list was sent accidentally. Zerhouni nonetheless investigated all the grants on the list and later wrote to Congress defending the studies. Now, Joanna Kempner, a sociologist at Rutgers University in Piscataway, New Jersey, has surveyed and interviewed many of the principal investigators whose grants came under scrutiny. She has found that many of them subsequently used less-controversial language and, in some cases, changed the focus of their work to avoid such areas altogether. © 2008 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 12239 - Posted: 06.24.2010

By Laura Sanders WASHINGTON — New research on brain activity confirms that people can be madly in love with each other long after the honeymoon is over. Researchers led by Bianca Acevedo at the Albert Einstein College of Medicine in New York wanted to know if romantic love — or at least the brain activity it triggers — could last in a long-term relationship. To everyone’s relief, the answer is yes. The group presented its results November 16 at the annual meeting of the Society for Neuroscience. The new data suggest that people who have been madly in love for an average of 21 years maintain activation in a brain region associated with early-stage love. “We now have physiological evidence that romantic love can last,” says coauthor Helen Fisher, a biological anthropologist from Rutgers University in New Brunswick, N.J. Most couples who have been together for many years experience a change from a frenetic, obsessive love to something more subdued and comfortable, says study coauthor Lucy Brown of Albert Einstein College of Medicine. But the researchers noticed a small group of outliers who had been with the same person many years and claimed to be as much in love as they were during the exciting early days of their relationship. Since that earlier study in 2005 using functional MRI brain imaging, the researchers knew that a certain part of the brain called the ventral tegmental area was activated when people who had been in love for relatively short times — an average of seven months — saw pictures of their sweethearts. © Society for Science & the Public 2000 - 2008

Keyword: Sexual Behavior; Emotions
Link ID: 12238 - Posted: 06.24.2010

by Alison Motluk RATS with breathing problems caused by damage to their nerves have had normal breathing restored by bursts of visible light aimed onto the spinal cord. This achievement raises hopes that a miniature light source implanted near the spine might one day allow people with similar injuries to breathe normally. In 2005, Ed Boyden at the Massachusetts Institute of Technology infected neurons in Petri dishes with viruses carrying the ChR2 gene, which codes for a light-sensitive protein called channelrhodopsin-2. The neurons started expressing the protein, and this allowed the researchers to use pulses of light to control when the neurons fired (Nature Neuroscience, vol 8, p 1263). "The nerve cells think they are photoreceptors," says neuroscientist Jerry Silver at Case Western Reserve University in Cleveland, Ohio. Silver has now taken things a step further with a study to investigate how this light-operated neuronal switch might be used to restore function lost as a result of nerve damage. His team cut part way through the spinal cords of rats at the second vertebra from the top, where the neck pivots, severing the connection between the spinal cord and the nerves that control one side of the diaphragm. This prevented messages from the brain getting to the diaphragm, leaving the animals with problems breathing. Similar injuries are the leading cause of death in people with spinal cord damage. © Copyright Reed Business Information Ltd

Keyword: Regeneration
Link ID: 12237 - Posted: 06.24.2010