Reaching out to touch a dot on a computer screen may seem simple, but it requires a complex chain of signals that link together the eye, brain and arm. Damage to any part of that chain, such as a spinal injury, stroke or neurodegenerative disease, can make even the simplest tasks impossible. In a new study, Stanford engineer Krishna Shenoy and a group of researchers at Caltech have shown that at least some links in that chain can be dramatically bypassed. The study is a significant advance in the growing field of neural prosthetics ­ implanted devices that eventually may help severely paralyzed patients regain some of their lost functions. The results of the study were presented by Daniella Meeker, a Caltech graduate student, at the annual meeting of the Society for Neuroscience in San Diego on Nov. 11.

Keyword: Robotics
Link ID: 1079 - Posted: 11.29.2001

What areas of the brain are activated during the process of learning and how does the pattern of activation change as learning proceeds? Brain imaging studies conducted by researchers at Massachusetts General Hospital (MGH) in collaboration with scientists at Rutgers University-Newark, are revealing that brain systems known to be involved in learning seem to compete with each other, with the type of learning involved determining which system is dominant. In a study appearing in the Nov. 29 issue of Nature, the researchers describe how increased activity in one brain system is associated with decreased activity in another system during learning of a simple skill. The findings ? which suggest how the brain mediates between the need to store and access a wide range of information and the need for virtually automatic responses in key situations may eventually lead to new strategies for dealing with learning disorders or for diagnosing Alzheimer's disease, Parkinson's disease and other brain disorders.

Keyword: Vision; Brain imaging
Link ID: 1078 - Posted: 11.29.2001

What would they say if they could speak? Three members of the family of great apes have a crucial speech-related brain feature previously thought unique to humans. This is the finding of a pair of researchers in Atlanta, Georgia, US, who carried out magnetic resonance imaging (MRI) scans on chimpanzees, bonobos and gorillas. They say they were surprised no-one had looked for the crucial lopsided structure in great apes before. The discovery could imply that evolution of brain structures linked to speech began before the ancestors of humans and apes parted ways. (C) BBC

Keyword: Language; Evolution
Link ID: 1077 - Posted: 11.29.2001

Minocycline May Slow Disease Progression By Daniel DeNoon WebMD Medical News -- A common antibiotic appears to have an interesting side effect: it may prevent Parkinson's disease. The antibiotic -- minocycline -- is known to have anti-inflammatory effects that are completely separate from its germ-killing activity. Because of this, it is often used to treat inflammatory diseases such as arthritis and acne. Now a U.S.-German research team shows that the drug protects mice in an experimental model of Parkinson's disease. Drugs like minocycline may prove effective in preventing and/or altering the progression of Parkinson's disease, report Yansheng Du, PhD, and colleagues of Indiana University and Lilly Research Laboratories, Indianapolis; and Philipps University, Marburg, Germany. The study appears in the Dec. 4 issue of the Proceedings of the National Academy of Sciences. © 1996-2001 WebMD Corporation. All rights reserved.

Keyword: Parkinsons
Link ID: 1076 - Posted: 11.29.2001

By JANE E. BRODY At least 12 million people in this country have a condition affecting their limbs that could give even the calmest among them the heebie-jeebies. It goes by the exceedingly apt name of restless legs syndrome and is characterized by a variety of discomforting sensations that occur at rest and compel sufferers to get up and move around. People describe the sensations as creeping, tingling, pulling, twitching, tearing, aching, throbbing, prickling or grabbing; some feel as if insects are crawling on them or an electric current is running through their limbs. Some even use the word painful. But whatever the nature of the sensation, the result is the same: an uncontrollable urge to relieve it by moving the affected limb. Yet, as common as this condition apparently is, most people have never heard of it and only about one in 10 sufferers has actually been given the diagnosis. And, since there are effective treatments, millions of people, for lack of a diagnosis, may suffer needlessly or resort to a host of unproven remedies to try to find relief. Copyright 2001 The New York Times Company

Keyword: Sleep
Link ID: 1073 - Posted: 11.28.2001

By David F. Salisbury The mosquito may be nature's most effective bioterrorist, accounting for millions of deaths each year. But the end of its eons-long reign of terror may be in sight. Scientists have begun to apply the power of genomics and molecular biology to understand how the mosquito detects the subtle chemical cues that lead it to its targets. "The mosquito is the most dangerous animal on the planet. It relies on its sense of smell to find the source of its blood meals. So understanding how its olfactory system works at the molecular level should suggest new and novel ways to keep it from spreading catastrophic diseases," says Laurence J. Zwiebel, assistant professor of biological sciences at Vanderbilt. His laboratory is the first to have identified the genes that code for proteins, called odorant receptors, which are a key part of the mosquito's olfactory system. © 2001 Vanderbilt University, All Rights Reserved

Keyword: Chemical Senses (Smell & Taste); Genes & Behavior
Link ID: 1072 - Posted: 11.28.2001

How to make a robotic arm that is able to flex in an infinite number of ways and order it to do so without disorder and confusion? Get yourself an octopus and study it. That is exactly what researchers funded by the Office of Naval Research are doing. Octopuses are boneless, brainy, and ancient invertebrates. They also have quite a problem on their hands, er, arms. Because they lack a rigid skeleton, the octopus can perform its tasks? reaching for a target, for example ? in practically infinite ways. But, in order not to spend too much time in untying its eight arms, each arm must not move independently of one another. ?How the octopus controls each arm so that tasks can be performed without chaos, and without the need to spend enormous time in deciding how to perform a specific arm movement, is precisely what robotics designers would like to know,? says Tom McKenna, ONR Program Manager on this study.

Keyword: Robotics
Link ID: 1071 - Posted: 11.28.2001

Scientists from Emory University School of Medicine and the University of Pavia, Italy, have determined for the first time the three-dimensional structure of monoamine oxidase B (MAO B) ? an enzyme important in several major disease processes; particularly age-related neurological disorders. Understanding the detailed structure of the enzyme should provide a framework for designing new neuroprotective drugs. The research will be published in the January 2002 print edition of Nature Structural Biology and in the online edition on Nov. 26, 2001. Monoamine oxidases (MAO B and MAO A) are well-known targets for antidepressant drugs and for drugs used to treat neurological disorders and diseases of aging, such as Parkinson?s disease and Alzheimers disease. MAO A and MAO B are attached to the outer membrane of the mitochondria ? the energy powerhouses of cells and function to oxidize amine neurotransmitters such as dopamine and serotonin.

Keyword: Biomechanics
Link ID: 1070 - Posted: 11.28.2001

Deficiencies in mother-infant relationship during infancy have been known to influence neonatal development and behavior. Such environmental shortcomings are thought to affect the vulnerability of the infant to certain neuropsychiatric disorders over its lifespan. Fluoxetine is often used for treating maternal separation-related mental disorders in children. The authors administrated fluoxetine to rat pups with maternal separation and social isolation to determine its effects on neuronal development, in particular with respect to cell proliferation and apoptosis in the dentate gyrus of the hippocampus. Compared to pups with maternal separation without fluoxetine treatment, pups with maternal separation and fluoxetine treatment showed a significantly increased number of BrdU-positive cells and a significantly decreased number of TUNEL-positive cells in the dentate gyrus. These data support that fluoxetine affects cell proliferation and apoptosis and that it may offer new therapeutic opportunities as an agent to counteract the effects of maternal separation. ### Citation source: Molecular Psychiatry 2001 Volume 6, number 6, pages 725-728.

Keyword: Stress; Development of the Brain
Link ID: 1069 - Posted: 11.28.2001

While the cause of Alzheimer?s disease (AD) is unknown, it has been speculated that the immune processes play a role. As part of the Canadian Study of Health and Aging, René Verreault and colleagues prospectively studied the possible relationship between exposure to vaccines and the risk of AD. Of 4392 community-living subjects who were cognitively unimpaired at baseline, 183 developed AD in the next 5 years. Multivariate logistic regressions were used to compare those who were and were not vaccinated, adjusting for age, sex and education. Past vaccinations were associated with a lower risk of developing AD (odds ratio [OR] 0.41, 95% confidence interval [CI] 0.27-0.62 for tetanus and diphtheria; OR 0.60, 95% CI 0.37-0.9 for poliomyelitis; OR 0.75, 95% CI 0.54-1.04 for influenza). While the authors state that their findings may result from the limited quality of available data on exposure to vaccines, the findings do support recent reports suggesting that both aging and Alzheimer?s disease may involve changes in immune responses.

Keyword: Alzheimers
Link ID: 1068 - Posted: 11.28.2001

Alzheimer's and Frau August D German scientist, psychologist and neuropathologist, Alois Alzheimer first met Frau August D late November 1901 when he began treating her for a puzzling disease. There was no documentation of her bizarre illness and its symptoms, though progressive mental detoriation due to old age was commonplace. Alzheimer recorded what he saw throughout the five years during which she was under his care. "When committed to the institution, her behavior was dominated by total helplessness. She was confused as to time and place. Occasionally she remarked that she did not understand anything and did not know her way about. At times she was delirious, and carried parts of her bed around, calling for her husband and daughter, and had auditory hallucinations. Often she screamed in a frightening voice for hours at a time," he wrote. © DW 2001

Keyword: Alzheimers
Link ID: 1067 - Posted: 11.28.2001

Ketone bodies (hydroxybutyrate and/or acetoacetate) are fluids are used routinely to treat trauma, intensive care and surgical patients. A new company is to develop them as treatments for stroke and chronic neurodegenerative conditions BTG, a technology commercialisation company, today launched KetoCytonyx Inc, a company created to develop BTG?s ketone body technology. KetoCytonyx will develop new treatments for acute brain injury such as stroke and chronic neurodegenerative conditions such as Alzheimer?s disease. Initially the company will be based at BTG?s office in Pennsylvania, USA. BTG will license the core intellectual property to KetoCytonyx and will provide intellectual property management, development planning, as well as general management and commercial strategy advice, in exchange for a majority equity stake. It will also initially invest £240,000 to create the company, with further investment anticipated in the near future.

Keyword: Stroke
Link ID: 1066 - Posted: 11.28.2001

Combination Improves Muscle Movements and Mood By Michael Smith , MD WebMD Medical News Nov. 27, 2001 -- Brain stimulation for Parkinson's disease continues to gain ground. A new study shows that it can reduce some of the problems people experience after taking drugs for a long time. In people with Parkinson's, levels of the brain chemical dopamine are too low. But, levodopa -- one of the first drugs used to treat Parkinson's symptoms -- increases the amount of dopamine. However, one of the problems in treating this progressive brain disease is that after years of use, levodopa often doesn't work so well. The effects tend to wear off and uncontrolled muscle movements return, which are very difficult to treat. © 1996-2001 WebMD Corporation. All rights reserved.

Keyword: Parkinsons
Link ID: 1064 - Posted: 11.28.2001

Deaf people use 'mind's ear' to process vibrations. ERICA KLARREICH After going deaf, Beethoven sawed the legs off his piano and played it on the floor so he could feel its vibrations. Nearly two centuries later, brain imaging is revealing that deaf people may 'hear' vibrations just like others hear sounds - using the auditory centres of the brain. When holding a vibrating plastic pipe, people born deaf have brain activity in the auditory cortex, but those with normal hearing don't, says Dean Shibata of the University of Washington. Shibata presented his findings on 27 November at the Scientific Assembly and Annual Meeting of the Radiological Society of North America in Chicago. The study suggests that the brain of a deaf person rewires itself to process vibrations in the absence of sound. * Levanen, S. et al. Feeling vibrations: enhanced tactile sensitivity in congenitally deaf adults. Neuroscience Letters, 301, 75 - 77, (2001). © Nature News Service / Macmillan Magazines Ltd 2001

Keyword: Hearing
Link ID: 1063 - Posted: 11.28.2001

by Dan Ferber It's no secret that sex hormones mess with the mind and alter behavior, and researchers have known, too, that they alter the shape of specific brain cells. But despite the logical connection, researchers have struggled to prove that the two effects are linked. Janis Weeks' team has shown precisely how steroid hormones affect individual neurons in a caterpillar with a simple nervous system, causing profound changes that help the caterpillar become a moth. The results, presented here in a special lecture, reveal how steroid hormones might affect other animal brains, including our own. Weeks and her colleagues at the University of Oregon study the simple nervous system of a caterpillar called the tobacco hornworm that has a body the length of a human hand. Like other caterpillars, it transforms into a pupa and then an adult moth, and entomologists have long known that a steroid hormone called 20-hydroxyecdysone (20E) triggers each step of the metamorphosis. © Elsevier Science Limited 2000

Keyword: Apoptosis; Hormones & Behavior
Link ID: 1062 - Posted: 11.27.2001

by Apoorva Mandavilli Nocturnal frontal lobe epilepsy (NFLE), an abnormal and violent sleep-related movement disorder, has recently been linked to mutations in the subunits of nicotinic acetylcholine receptors (NAChR). The mutations themselves do not directly trigger synchronous firing, California researchers suggested today at the annual meeting of the Society for Neuroscience here. Rather, a decrease in calcium potentiation of the receptors appears to allow a sort of neurological "white noise," which normally travels around the cortex in a controlled fashion during quiet sleep, to disseminate broadly across the entire cortex. NFLE is characterized by twisting and jerking movements, and often accompanied by screaming or other vocalizations. The disorder is commonly misdiagnosed as ordinary motor parasomnias, such as night terrors or sleepwalking. Unlike parasomnias, however, the average age of onset is 10-12 years and displays as clusters of short (less than 60 seconds) movements that recur almost every night, sometimes several times a night. In contrast, parasomniac episodes fade with adolescence, occur much less frequently, and last longer than 3 minutes on average. © Elsevier Science Limited 2000

Keyword: Epilepsy; Sleep
Link ID: 1061 - Posted: 11.27.2001

by Dan Ferber If you want people to remember something you tell them, pay them a dollar afterward. That's the conclusion of a study reported here today. Payments after a study session helped subjects recall a list of words a week later. Another study reported at the same session showed that the effects of emotion on memory fade with age and early Alzheimer's disease. Psychologists have known for years that we tend to remember emotionally loaded experiences better than neutral ones, but they don't yet know how we do it. In past studies, researchers had shown that subjects remembered better when they feel bad at the time they were socking away memory. But no one had tested the effects of making the subjects feel good, says Kristy Nielson of Marquette University. Nielson and a colleague had three groups of subjects try to memorize a list of 30 words. After testing them for recall immediately afterward, they sent them on their way. Before they left, however, the researchers praised one group, did nothing for another group, and paid a third group a dollar. © Elsevier Science Limited 2000

Keyword: Learning & Memory
Link ID: 1060 - Posted: 11.27.2001

by Roberta Friedman So many diseases that destroy the aging brain have been linked with clumping proteins, yet the debate over cause and effect continues. Presented here today, recent findings bolster evidence that protein aggregates themselves may not damage nerve cells directly, or produce the clinical signs. The fibers and where they first appear cause the problem, contend researchers at the University of California, who presented a new way to visualize the process microscopically. Although diseases such as Huntington's and Alzheimer's are described collectively as neurodegeneration, some of their dysfunction may be due to the toxic effects of soluble forms of the affected proteins, says Steven Finkbeiner, assistant investigator at the Gladstone Insitute of Neurological Disease at UC San Francisco. They may actually precede the deposition of the protein in the brain as clumps. © Elsevier Science Limited 2000

Keyword: Huntingtons; Genes & Behavior
Link ID: 1059 - Posted: 11.27.2001

by Roberta Friedman Traditional electron microsopy, supercharged with new computer power, is poised to reveal the exact nature of the molecular structure of the nerve synapse. But due to cuts in funding, Jack McMahan says, a generation of trained microscopists is not there to step up to the task. Speaking here to an airplane hangar-sized room filled with neuroscientists, McMahan projected lilac- and gold-tinted pictures of the active zone of the nerve ending, generated by computer from electron micrographs. His images suggest that an intricate structure of already characterized proteins acts to tie synaptic vesicles at the calcium channels, the crucial triggers for the release of nerve cell messages. © Elsevier Science Limited 2000

Keyword: Miscellaneous
Link ID: 1058 - Posted: 11.27.2001

by Roberta Friedman Details presented here about receptors for the quickly acting nerve cell messengers suggest new therapeutic targets, and show how two systems of nerve signals are linked. At a symposium on the emerging knowledge about how inhibitory messages are received by neurons, Stephen Moss described a new role for a couple of previously known proteins, and suggested that they form a link between slow transmission by the catecholamines and the fast inhibitory transmission by GABA. The slowly acting catecholamines such as dopamine and norepinephrine work through a cascade of kinases that either add phosphate molecules to key proteins inside the neuron, or remove them. Unpublished new findings by Moss, who is a pharmacologist at the University College, London, also link these kinases, called PKA and PKC, to the receptor on the neurotransmitter molecule GABA, which is responsible for fast inhibitory transmission as it crosses a synapse. The link occurs via proteins called RACK (receptor for activated C kinase) and AKAP (A-Kinase anchoring protein). © Elsevier Science Limited 2000

Keyword: Miscellaneous
Link ID: 1057 - Posted: 11.27.2001