By GARDINER HARRIS WASHINGTON, — The Food and Drug Administration said Thursday that "no sound scientific studies" supported the medical use of marijuana, contradicting a 1999 review by a panel of highly regarded scientists. Susan Bro, an agency spokeswoman, said Thursday's statement resulted from a past combined review by federal drug enforcement, regulatory and research agencies that concluded "smoked marijuana has no currently accepted or proven medical use in the United States and is not an approved medical treatment." Ms. Bro said the agency issued the statement in response to numerous inquiries from Capitol Hill but would probably do nothing to enforce it. "Any enforcement based on this finding would need to be by D.E.A. since this falls outside of F.D.A.'s regulatory authority," she said. Eleven states have legalized medicinal use of marijuana, but the Drug Enforcement Administration and the director of national drug control policy, John P. Walters, have opposed those laws. A Supreme Court decision last year allowed the federal government to arrest anyone using marijuana, even for medical purposes and even in states that have legalized its use. Copyright 2006 The New York Times Company

Keyword: Drug Abuse
Link ID: 8811 - Posted: 06.24.2010

Whether it's from surgery, an accident or stroke, when the brain is injured, the damage is usually permanent. Most of the time, the cells of the brain don't grow back. But two researchers at Massachusetts Institute of Technology are working to change that. "The problem we're trying to solve with the research is how to reconnect disconnected parts of the brain," says one of the researchers, neuroscientist Rutledge Ellis-Behnke. He and professor Gerald Schneider of the M.I.T. Department of Brain and Cognitive Sciences are using nanotechnology to create tiny bridges that can help brain cells grow back together. The bridges assemble themselves from protein fragments called peptides, which are injected into the injured area. The bridges are similar to the normal structures among brain cells. "It would be easy to fool an anatomist into thinking that this was part of the brain," says Schneider about these bridges that are smaller than the width of a human hair. He adds that "it's functioning like it's part of the natural material that fills spaces between the nerve cells in the brain." The peptide nano-bridges are not permanent. After a while they dissolve. © ScienCentral, 2000-2006.

Keyword: Regeneration; Stroke
Link ID: 8809 - Posted: 06.24.2010

By Susan S. Lang A honeybee swarm bivouacs on a tree branch, waiting for scout bees to select candidate sites for a new home, deliberate among the choices and then reach a verdict -- a process "complicated enough to rival the dealings of any department committee," says Cornell biologist Thomas Seeley. When 10,000 honeybees fly the coop to hunt for a new home, usually a tree cavity, they have a unique method of deciding which site is right: With great efficiency they narrow down the options and minimize bad decisions. Their technique, says Cornell University biologist Thomas Seeley, includes coalition building until a quorum develops. The Seeley group's study, which is published in the May-June issue of American Scientist, might well be used to help improve human group decision-making, he says. Scientists had known that honeybee scouts "waggle dance" to report on food. Seeley and his colleagues, however, have confirmed that they dance to report on real estate, too, as part of their group decision-making process. The better the housing site, the stronger the waggle dance, the researchers found, and that prompts other scouts to visit a recommended site. If they agree it's a good choice, they also dance to advertise the site and revisit it frequently.

Keyword: Animal Communication
Link ID: 8808 - Posted: 04.21.2006

By Katherine Unger Written words have only been around for about 6000 years, but that hasn't kept some scientists from believing that there's a specific part of our brain devoted to reading. Now this controversial idea is getting an important piece of support from a man whose surgical procedure may have disrupted this region. The existence of a brain region dedicated to reading was first proposed by neurologist Jules Déjerine in the late 19th century. Brain scans appear to support the hypothesis: The region--called the visual word form area (VWFA) and located in the rear of the brain's left hemisphere--lights up when individuals read words. But skeptics note that the same thing happens when subjects gaze upon faces or objects, indicating that the area isn't specialized to process only written language. A chance opportunity allowed neuroscientists led by Laurent Cohen of INSERM, the Université Paris and the Hôpital de la Salpêtrière in France to put the theory to the test. The team became aware of a man who was about to have brain surgery to treat epilepsy. The surgery was to remove a small area next to the VWFA, so Cohen's team carried out a set of experiments. Prior to the surgery, the man took 600 milliseconds to read common words of three to nine letters. The word's length didn't affect the speed of his response. Functional MRIs and electrodes implanted in the man's brain showed activation specifically in the VWFA when he read words; distinctly different areas lit up when he named objects such as tools. © 2006 American Association for the Advancement of Science.

Keyword: Language
Link ID: 8807 - Posted: 06.24.2010

By Tracy Staedter, Discovery News — A rat nerve cell attached to a semiconductor chip has exchanged a signal with the chip, an achievement that could lead to organic computers that process information like a brain, say researchers. In the long term, the technology also could lead to prosthetic limbs that are controlled by a person's brain and nerves. "If you know how single neurons couple to a chip, you can learn how whole tissue couples to a chip," said Peter Fromherz, professor of biophysics at Max Planck Institute for Biochemistry in Germany and coordinator of the so-called NaChip project, which also involves researchers from the University of Padua, Italy, and the University of Zurich, Switzerland. To make the nerve cell and the chip compatible, the researchers worked with German microchip company Infineon to modify the chip's surface. The resulting one-millimeter chip has more than 16,000 transistors that match up with ion-carrying channels in the nerve cell. The chips were specially coated so that they could be immersed in a solution meant to keep the nerve cell alive. © 2006 Discovery Communications Inc.

Keyword: Robotics
Link ID: 8806 - Posted: 06.24.2010

NEUROFEEDBACK practice may be able to alleviate some of the symptoms of autism, according to a pilot study on eight children with the disorder. The technique involves hooking people up to electrodes and getting them to try and control their brain waves. In people with autism, the "mu" wave is thought to be dysfunctional. Since this wave is associated with "mirror neurons" - the brain cells that underpin empathy and understanding of others - Jaime Pineda at the University of California, San Diego, wondered if controlling it through neurofeedback could exercise faulty mirror neurons and improve their function. He attached sensors to the necks and heads of eight children with autism and had them watch a video game of a racing car going round a track. For all of the children, sitting still and concentrating kept the car travelling around the track, but five of them were also able to harness their mu waves and use them to adjust the car's speed. After 30 sessions over 10 weeks, Pineda found that the five children's mu brainwaves had changed and they performed better on tasks involving imitation, typically difficult for people with autism. Pineda presented his work at the annual meeting of the Cognitive Neuroscience Society in San Francisco last week. © Copyright Reed Business Information Ltd.

Keyword: Autism; Vision
Link ID: 8805 - Posted: 06.24.2010

Gaia Vince Everybody has experienced a sense of “losing oneself” in an activity – being totally absorbed in a task, a movie or sex. Now researchers have caught the brain in the act. Self-awareness, regarded as a key element of being human, is switched off when the brain needs to concentrate hard on a tricky task, found the neurobiologists from the Weizmann Institute of Science in Rehovot, Israel. The team conducted a series of experiments to pinpoint the brain activity associated with introspection and that linked to sensory function. They found that the brain assumes a robotic functionality when it has to concentrate all its efforts on a difficult, timed task – only becoming "human" again when it has the luxury of time. Ilan Goldberg and colleagues used functional magnetic resonance imaging (fMRI) to scan the brains of nine volunteers during the study. Participants were shown picture cards and told to push buttons to indicate whether or not an animal was depicted. The series was shown slowly the first time, and at three times the rate on the second run through. On its third showing, the volunteers were asked to use the buttons to indicate their emotional response to the pictures. The experiment was then repeated using musical extracts, rather than pictures, and asked to identify whether a trumpet played. © Copyright Reed Business Information Ltd.

Keyword: Attention
Link ID: 8804 - Posted: 06.24.2010

Evidence is mounting that estrogen, a hormone critical to a woman's sexual development, should also be thought of as a neurotransmitter when acting in the brain, a Johns Hopkins University behavioral neuroscientist said. Gregory Ball, professor in the Department of Psychological and Brain Sciences in the university's Krieger School of Arts and Sciences, has added to that evidence with an article, written with a Belgian collaborator, to be published in the May issue of Trends in Neuroscience. Their research, studying estradiol (a form of estrogen) in the brains of quail, suggested that estrogen in its role as a neurotransmitter, or brain signaling chemical, helps to regulate male sexual activity and the levels at which pain is perceived. "How we categorize estradiol is of more than semantic interest," Ball said of adding the "neurotransmitter" label to the estrogen's traditional label of "hormone." "It influences how scientists conduct research, the kind of experiments we do, and even the way we design clinical interventions that involve actions of estrogen in the brain." In the article, the team argues that brain estrogens display many, if not all, of the functional characteristics of neurotransmitters. They are released at synapses (the tiny spaces between neurons) and act rapidly (often within minutes) to affect the activity of neighboring cells.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 8803 - Posted: 04.21.2006

By ALAN RIDING LONDON, — More than most art forms, opera demands a suspension of disbelief. For a long time this included accepting that a man could sing with the voice of a woman. It was not a natural gift, but the results often drove audiences wild: castrati, as they were known, were among the rulers of the 18th-century opera stage. True, most of the Italian boys who were castrated to preserve their unbroken voices never achieved fame . Yet enough did to encourage some impoverished parents to allow one or two of their sons to undergo this pre-pubescent mutilation. In the 1730's, it has been estimated, as many as 4,000 boys were so altered each year. Intense musical training followed, so that, by their midteens, the youths were ready to sing in church choirs. Then, with opera all the rage from Naples to Venice, the best voices were selected by theater managers for the stage. A few became stars across Europe. Those seeking the highest fees headed for London, where Handel was presiding over a boom in Italian opera. "Handel and the Castrati," a revealing small show at the Handel House Museum here through Oct. 1, tells their stories. On display are a few objects, including an 18th-century iron "castratori" instrument, as well as paintings, engravings, music scores and recorded excerpts from Handel operas and oratorios, with castrato roles now sung by counter-tenors and mezzo-sopranos. Copyright 2006 The New York Times Company

Keyword: Hormones & Behavior; Hearing
Link ID: 8802 - Posted: 06.24.2010

BUFFALO, N.Y. -- Researchers at the University at Buffalo affiliated with the New York State Center of Excellence in Bioinformatics and Life Sciences have identified a novel agent that can protect neurons involved in Parkinson's disease from being destroyed by the pesticide rotenone. The agent, called L-AP4, activates a critical group of receptors called group III metabotropic glutamate receptors and may be a promising drug target. Currently there is no known cure for Parkinson's disease. Long-term studies have shown that environmental toxins play a critical role in the development of Parkinson's disease, and it has been shown recently in research with rats that administering rotenone, a naturally occurring substance widely used as a pesticide, destroys dopamine-producing neurons and causes symptoms of Parkinson's disease in this animal model. In the April 19 issue of The Journal of Neuroscience, UB researchers lead by Jian Feng, Ph.D., report that activation of group III metabotropic glutamate receptors reverses a cascade of events triggered by rotenone that destroys dopamine neurons. Feng, UB associate professor of physiology and biophysics, and colleagues earlier demonstrated that microtubules, the intracellular highways for transporting dopamine and many vital cellular components, are critical for the survival of dopamine neurons, which are responsible for controlling body movement. © 2006 University at Buffalo.

Keyword: Parkinsons
Link ID: 8801 - Posted: 06.24.2010

Spring is the season for flashy mates, at least for finches. It is only later in the year that the females choose based on genetic diversity, according to new research from two scientists at the University of Arizona. Their 10-year study of a colony of 12,000 finches in Montana has revealed the seasonal dynamics of finch attraction and thereby resolved an evolutionary conundrum. Previous research had shown that female birds go for the most resplendent mates; in the case of finches, this means the males with the reddest breast. Some scientists argue that such sexual selection is the driving force behind apparently useless displays, such as red breasts or the brilliance of a male peacock's tail. "For such elaborate traits to evolve, you have to have mating patterns where everyone wants the same thing," explains ecologist Kevin Oh. On the other hand, in a relatively stable population, if all females mated with the flashiest guy, the charm of finches would become inbred. Instead, female finches should seek out males with the most genetic difference from themselves. But this would lead to a variety of hues for male finch breasts. "Even though preference for genetically complementary mates is widely documented, it has always puzzled people that individual differences in mate preference do not prevent the evolution of elaborate ornaments," notes ecologist Alexander Badyaev. © 1996-2006 Scientific American, Inc

Keyword: Sexual Behavior; Evolution
Link ID: 8800 - Posted: 06.24.2010

Cuttlefish are wizards of camouflage. Adept at blending in with their surroundings, cuttlefish are known to have a diverse range of body patterns and can switch between them almost instantaneously. New research from MBL Marine Resources scientists, to appear in the May 2006 issue of the journal Vision Research, confirms that while these masters of disguise change their appearance based on visual cues, they do so while being completely colorblind. While previous research has reported cuttlefish colorblindness, MBL Research Associate Lydia Mäthger and her colleagues in Roger Hanlon’s laboratory approached the problem in more depth and with a new behavioral assay. The researchers tested cuttlefish (Sepia officinalis) color perception through observing the animal’s behavioral response to a series of checkerboard patterned substrates of various colors and brightnesses. They found that the animals did not respond to the checkerboard pattern when placed on substrates whose color intensities were matched to the Sepia visual system, suggesting that these checkerboards appeared to their eyes as uniform backgrounds. However, their results showed that cuttlefish were able to detect contrast differences of at least 15%, which Mäthger and her colleagues suspect might be a critical factor in uncovering what determines camouflage patterning in cuttlefish. © 2005 by The Marine Biological LaboratoryTM

Keyword: Vision
Link ID: 8799 - Posted: 06.24.2010

Scientists supported by the National Institute of Dental and Craniofacial Research (NIDCR), part of the National Institutes of Health, report in this week’s Journal of the American Medical Association the results of the first-ever randomized clinical trials to evaluate the safety of placing amalgam fillings, which contain mercury, in the teeth of children. Both studies — one conducted in Europe, the other in the United States — independently reached the conclusion: Children whose cavities were filled with dental amalgam had no adverse health effects. The findings included no detectable loss of intelligence, memory, coordination, concentration, nerve conduction, or kidney function during the 5-7 years the children were followed. The researchers looked for measurable signs of damage to the brain and kidneys because previous studies with adults indicated these organs might be especially sensitive to mercury. The authors noted that children in both studies who received amalgam, informally known as “silver fillings,” had slightly elevated levels of mercury in their urine. But after several years of analysis, they determined the mercury levels remained low and did not correlate with any symptoms of mercury poisoning. “What’s particularly impressive is the strength of the evidence,” said NIDCR director Dr. Lawrence Tabak. “The studies evaluated mercury exposure in two large, geographically distinct groups of children and reached similar conclusions about the safety of amalgam.”

Keyword: Neurotoxins; Development of the Brain
Link ID: 8798 - Posted: 06.24.2010

Michael Hopkin It seems that the more macho a man is — at least according to his hormones — the more the sight of an attractive woman will affect his judgement. Researchers at the University of Leuven in Belgium asked men to play an ultimatum game, in which they split a certain amount of money between them. High-testosterone men drove the hardest bargain — unless they had previously viewed pictures of bikini-clad models, in which case they were more likely to accept a poorer deal. The sight of flesh had less effect on the bargaining tactics of low-testosterone men. The testosterone dose that interested the researchers was that encountered by their participants when developing in the womb. This can be measured by comparing the lengths of the index and ring fingers — a relatively long ring finger is a sign of a high-testosterone man. For these men, even handling a bra was enough to sap their resolve, report economists Bram Van den Bergh and Siegfried Dewitte, who publish their findings in the journal Proceedings of the Royal Society B1. Pictures of landscapes or elderly women, or handling a t-shirt, had no effect on the men's steely bartering power. ©2006 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 8797 - Posted: 06.24.2010

KINGSTON, Ont. – The reason people can approach animals in the wild more easily from a car than by foot may be due to an innate "life detector" tuned to the visual movements of an approaching predator's feet, says Queen's University psychologist Niko Troje. "We believe this visual filter is used to signal the presence of animals that are propelled by the motion of their feet and the force of gravity," suggests Dr. Troje, Canada Research Chair in Vision and Behavioural Sciences. Conducted with Dr. Cord Westhoff from the Ruhr-Universität Bochum in Germany, the study was funded by the Canada Foundation for Innovation and the German Volkswagen Foundation. It will be published on-line April 18 in the international journal Current Biology. The researchers suggest this low level locomotion detector is part of an evolutionary old system that helps animals detect quickly – even on the periphery of their visual field – whether a potential predator or prey is nearby. "Research on newly hatched chicks suggests that it works from very early on in an animal's development," says Dr. Troje. "It seems like their brains are 'hard wired' for this type of recognition." One impetus for starting this research several years ago was a question by his young daughter, who asked him why she could get so much closer to wild rabbits in their neighborhood while riding on her bicycle rather than on foot. "I didn't have an answer for her then. Now, I think I have one," he says.

Keyword: Vision; Aggression
Link ID: 8796 - Posted: 06.24.2010

Studies of the brain using the video game Duke Nukem have shown how sleep affects long-term memory. The Belgian team used MRI scans to see how volunteers stored spatial information from the game. Sleep-deprived gamers recalled information from a different part of the brain to those who slept. Writing in Proceedings of the National Academy of Sciences (PNAS), the team said its work also shed light on how we navigate in the real world. "If you move to a new town, you have to think about where you are going," said Pierre Orban of Liege University in Belgium, one of the authors on the paper. But with time, once you know the city, you don't have to think about your route anymore." This automatic behaviour may be enhanced by sleep, the researchers believe. It mimics patterns of memory formation seen when a task is repeated. The work also explains how the brain is able to file and store this information. It has long been thought that sleep deprivation affects your ability to consolidate memories. To test the theory, the researchers gave the volunteers place-finding missions in a virtual city created in the Duke Nukem game. After an initial period of training to get used to the virtual terrain, the gamers were asked to find landmarks around the city while the scientists mapped their brain activity with MRI. (C)BBC

Keyword: Sleep; Learning & Memory
Link ID: 8795 - Posted: 04.18.2006

By ANNIE LUBLINER LEHMANN It would have been easy to ignore in other children, but when it comes to Jonah, our autistic son, nothing is beyond scrutiny. He was home on summer break from his residential school, and though his appetite was good and his behavior typical, watery droplets ran from his nose. There were no other cold symptoms, just a slow dribble that collected in the crease above his lips. The school nurse had called the week before to report that Jonah, who was almost 13 at the time, had taken a tumble, something he did more often than most. He was a slip-and-fall kind of guy, seeing only what he wanted, never the things that were in his way. We'd had many rides to the emergency room and knew from experience that any scans or X-rays would require general anesthesia, heavy artillery for a routine test. Hoping to avoid a hospital ordeal, the nurse agreed to follow Jonah closely for the next hours and days. She phoned often, assuring me that Jonah was fine, "up to his old tricks." I believed her and besides, he'd be home in a few days. I would be able to judge for myself. Copyright 2006 The New York Times Company

Keyword: Autism
Link ID: 8794 - Posted: 04.18.2006

By NICHOLAS WADE Researchers have made progress in understanding how a variant gene linked to schizophrenia may exert its influence in the brain. The findings are tentative but, if confirmed, could yield deep insights into the biological basis of the disease. The gene, called neuregulin-1, was first implicated in schizophrenia in 2002 by DeCode Genetics, a Reykjavik company that looks for the genetic roots of common diseases in the Icelandic population. But how the variant form of the gene contributed to the disease was far from clear, in part because even the normal gene's function is far from understood. A team led by Amanda J. Law of the University of Oxford in England and Daniel R. Weinberger of the National Institutes of Health has now developed clues as to how the gene may go wrong. Neuregulin is one of about 10 genes so far linked to schizophrenia. It plays many different roles in the brain, some concerned with synapses, the interconnections between neurons, so derangements of its function are a plausible source of schizophrenia. It is a long road, however, from knowing a variant gene is linked with a disease to understanding the biology of how the disease is caused. Copyright 2006 The New York Times Company

Keyword: Schizophrenia; Genes & Behavior
Link ID: 8793 - Posted: 04.18.2006

By JANE E. BRODY Faith Sullivan of Minneapolis was having a really hard time getting a good night's sleep. For years, she had slept about seven hours a night. Then, in her late 50's, something changed. After going to bed at 10 or 11 p.m., she would wake up around 3 a.m., unable to fall back to sleep. No, neither depression nor hot flashes were disrupting her night's rest. It was caffeine. She never drank caffeinated coffee in the evening, but she often had it as a midafternoon pick-me-up. Though she found it hard to believe that coffee at 4 p.m. could disturb her sleep at 3 a.m., at the suggestion of a friend she tried cutting it out. The result was striking. Within a day, she was back to sleeping seven hours a night. While not every insomniac's problem is so easily solved, many if not most of the millions of Americans who now rely on sleeping pills could cure their insomnia simply by changing their living and sleeping habits. Caffeine is not just in coffee. It's in tea, colas and other soft drinks, some herbal teas, chocolate and some medications (Anacin and Excedrin, for example). There's even a little caffeine in decaffeinated coffee and tea. For people highly sensitive to caffeine, its stimulant effects can last as long as 20 hours. Even decaffeinated coffee in the evening can keep me awake. Copyright 2006 The New York Times Company

Keyword: Sleep
Link ID: 8792 - Posted: 04.18.2006

New York, New York ––A recent study directed by the Mount Sinai School of Medicine suggests a ketogenic- high caloric diet may prevent the progression of Amyotrophic Lateral Sclerosis (ALS). This study, which appears in the April 3, 2006 issue of BMC Neuroscience, is the first to draw a correlation between diet and neuronal cell death, the cause of ALS. ALS is an adult-onset neurodegenerative disorder in which spinal and cortical motor neurons die causing relentlessly progressive weakness and wasting of skeletal muscles through the body. "ALS is such a devastating disease for those individuals diagnosed with the disorder," said Giulio Maria Pasinetti, M.D., Ph.D., Professor of Psychiatry and Neuroscience, Director of the Neuroinflammation Research Center at The Mount Sinai School of Medicine and lead author of this study. "The findings assert the significance of certain high caloric dietary intake in the prevention of ALS. In view of any available therapeutic application for the disease, this new evidence might bring hope to those affected." The cause of neuronal death in ALS is uncertain but study researchers say mitochondrial dysfunction plays an important role. Ketones promote mitochondrial energy production and membrane stabilization. Mitochondiral membrane dysfunction, loss of oxidative stress control, generation of excessive free radicals, neurofilament accumulation, and excitotoxicity are all implicated in the onset of ALS.

Keyword: ALS-Lou Gehrig's Disease
Link ID: 8791 - Posted: 06.24.2010