Like a double-edged sword, radiation therapy for brain cancer wipes out tumors but sometimes causes cognitive decline as well. Now researchers have found that, in rat brains, the treatment prevents new neurons from growing. Further findings suggest that dampening the brain's inflammatory response to radiation therapy may help avert such damage. To destroy brain tumors, neurosurgeons give patients a strong dose of radiation that’s supposed to kill the fastest growing cells--those in the tumor--while leaving slow-growing neurons alone. Years later, however, patients cured of brain cancer often lose their ability to make new memories. Researchers suspected that radiation therapy damages the stem cells that give rise to new neurons, which are concentrated in the hippocampus, a brain region necessary for storing memories. Copyright © 2002 by the American Association for the Advancement of Science.

Keyword: Neurogenesis; Stem Cells
Link ID: 2417 - Posted: 06.24.2010

- A crucial piece of the puzzle into how the eye becomes wired to the brain has been revealed by scientists at the Salk Institute for Biological Studies in La Jolla, Calif., and UT Southwestern Medical Center at Dallas. In findings published in today’s edition of Neuron , the researchers report that a certain class of Eph receptors and ephrin ligands - proteins that cause cells to either repel or attract each other - control how nerve connections from the developing eye form maps that present what we see to visual centers in the brain. Neurobiologists had long sought to answer how neural maps are established. © 2002 The University of Texas Southwestern Medical Center at Dallas

Keyword: Development of the Brain; Vision
Link ID: 2416 - Posted: 06.24.2010

New insights into how language warps the brain By W. Wayt Gibbs "Liver." The word rises from the voice box and passes the lips. It beats the air, enters an ear canal, sets nerve cells firing. Electrochemical impulses stream into the auditory cortex of a listener's brain. But then what? How does the brain's neural machinery filter that complex stream of auditory input to extract the uttered word: "liver"--or was it "river," or perhaps "lever"? Researchers at the Acoustical Society of America meeting in June reported brain imaging studies and clinical experiments that expose new details of how the first language we learn warps everything we hear later. Some neuroscientists think they are close to explaining, at a physical level, why many native Japanese speakers hear "liver" as "river," and why it is so much easier to learn a new language as a child than as an adult. At the ASA conference, Paul Iverson of University College London presented maps of what people hear when they listen to sounds that span the continuum between the American English phonemes /ra/ and /la/. Like many phonemes, /ra/ and /la/ differ mainly in the three or four frequencies that carry the most energy. Iverson had his computer synthesize sounds in which the second and third most dominant frequencies varied in regular intervals, like dots on a grid. He then asked English, German and Japanese speakers to identify each phoneme and to rate its quality. © 1996-2002 Scientific American, Inc. All rights reserved

Keyword: Language
Link ID: 2415 - Posted: 06.24.2010

By Elizabeth Weise, USA TODAY President Bush raised a lot of hope but also generated dire warnings a year ago Friday when he decided to limit the use of federal money for research on embryonic stem cells. Now it's clear that neither the hopes nor the fears have fully materialized. Stem cells, found in all human embryos at their earliest stages of development, are the undifferentiated cells capable of turning into all cells the body needs for development. If science could harness their potential, researchers see the prospect of harvesting the cells to treat some of the world's cruelest killers — teaching stem cells to become new brain cells for Parkinson's patients and to form spinal cords for the paralyzed and new insulin-producing cells for diabetics. But harvesting the cells destroys the blastocyst, the 200-cell hollow ball that develops four to six days after sperm meets egg, while creating an ethical issue for many and a serious moral concern for Bush, who believes life begins at conception. © Copyright 2002 USA TODAY, a division of Gannett Co. Inc.

Keyword: Stem Cells; Parkinsons
Link ID: 2414 - Posted: 06.24.2010

Calming brain circuit could treat anxieties. HELEN PEARSON Brain chemicals similar to those in cannabis wipe out bad memories - and could point to new drugs for severe anxiety. The chemicals are called cannabinoids. Mice with faulty cannabinoids can't forget traumatic events, Beat Lutz of the Max Planck Institute of Psychiatry in Munich, Germany and his colleagues have found1. They suggest that the chemicals wipe fearful memories from the brain. Drugs that boost cannabinoids could help people who suffer post-traumatic stress disorder, phobias and panic attacks, say the researchers. © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Emotions; Drug Abuse
Link ID: 2413 - Posted: 06.24.2010

Mainstream psychiatric outcast ponders parasitic mental illness Keay Davidson, Chronicle Science Writer ©2002 San Francisco Chronicle. An unknown infectious agent may be responsible for a five-fold increase in mental illness over the last two centuries, a controversial psychiatrist proposes in a new book. The claim by Dr. E. Fuller Torrey, a noted psychiatrist-author and scourge of mainstream psychiatry, challenges common explanations that mental illness is caused by a combination of genetic factors and environmental influences, such as family upbringing. Torrey's new book also defies two schools of academic thought: One is that rates of at least one major type of mental illness, schizophrenia, have sharply declined or remained stable. ©2002 San Francisco Chronicle.

Keyword: Schizophrenia
Link ID: 2412 - Posted: 06.24.2010

One of the brain's most important chemical messengers has led Johns Hopkins School of Medicine researchers on a wild ride. Primarily interested in how and why nerve cells die in neurodegenerative diseases like Lou Gerhig's disease, the scientists now find themselves with a new rat model of epilepsy, a disease characterized not by cell death, but by rapid and uncontrolled "firing" of brain cells. Aware that extra amounts of the messenger can kill brain cells by over-stimulating them, the scientists thought preventing it from getting into cells might lead to cell death. But blocking one of the messenger's main transporters didn't kill nerve cells; instead, the rats developed epilepsy, complete with periods of staring and "freezing," the scientists report in the August 1 issue of the Journal of Neuroscience. "We wanted to see how reducing transport of this messenger affected other brain chemicals and the brain itself, but we hadn't expected it to result in epilepsy," says Jeffrey Rothstein, M.D., Ph.D., professor of neurology and neuroscience at Johns Hopkins. "Now we need to track it down in people to see if the same mechanism is involved in the human condition."

Keyword: Epilepsy
Link ID: 2411 - Posted: 08.05.2002

Cannabinoid receptor important in erasing aversive memories Using the model of fear conditioning in mice, researchers of the Max Planck Institute of Psychiatry together with colleagues from Naples were able to show that the cannabinoid receptor is important in erasing fear behavior. The researchers report in the current issue of the journal Nature 1st August 2002 that in mouse mutants lacking the cannabinoid receptor CB1, erasure of fear behavior evoked by an aversive acoustic sound was considerably lessened compared to normal control mice. The researchers hope that these findings will lead to new approaches for the treatments of phobias, posttraumatic stress disorders, and certain forms of chronic pain. It is part of our evolutionary heritage that we are alert to potentially dangerous situations, such as confined spaces, wide open spaces, lofty heights, or situations where we are confronted by animals perceived to be repulsive or possibly dangerous for us, such as spiders or snakes. Although it is important to be aware of potential and real threats, it is equally important to react appropriately to them. In most human beings, the initial moment of alertness and the subsequent reactions are correctly balanced, and they are able to relax rather fast and to react well-planned if the expected "disaster" has not occurred.

Keyword: Emotions; Stress
Link ID: 2410 - Posted: 08.05.2002

When you gaze at a bowl of fruit, why don't some of the bananas look red, some of the apples look purple and some of the grapes look yellow? This question isn't as nonsensical as it may sound. When your brain processes the information coming from your eyes, it stores the information about an object's shape in one place and information about its color in another. So it's something of a miracle that the shapes and colors of each fruit are combined seamlessly into distinct objects when you look at them. Exactly how the brain recombines these different types of visual information after it has broken them apart is called the "binding problem" and is currently the subject of considerable controversy in the neuroscience community. But the results of a brain mapping experiment, published online by the Proceedings of the National Academy of Sciences on July 29, provide significant new support for the theory that attention is the glue that cements visual information together as people scan complex visual scenes.

Keyword: Attention; Vision
Link ID: 2409 - Posted: 08.05.2002

Study shows damaged brain finds new ways to function Toronto, ONT. -- People who have suffered a moderate to severe traumatic brain injury (TBI) can recover some of their memory function by using alternate brain networks, according to a new study in the August 2002 issue of the Journal of Neurology, Neurosurgery and Psychiatry. TBI, often sustained in traffic accidents, is one of the most common causes of disability in young adults. People with TBI frequently complain of memory problems that interfere with their daily function and ability to work, yet many eventually recover memory function and return to work or school. The study, led by scientist Brian Levine of The Rotman Research Institute at Baycrest Centre for Geriatric Care, compared brain function in two groups of adults -- six patients who had suffered a moderate to severe TBI four years earlier (with several days of coma in some cases)and made a strong recovery, and 11 healthy adults who matched the TBI group in age and education.

Keyword: Regeneration
Link ID: 2408 - Posted: 08.05.2002

Anorexia nervosa mainly afflicts young women. The sufferers become obsessed with the importance of losing weight to the point where they become skeletal. A fatal outcome is all too common in this serious disorder. To decrease their weight, sufferers either restrict their eating only (restricting anorexia nervosa), or vomit what they eat. Stress and anxiety are emotions experienced intensely by sufferers with anorexia nervosa. Stress and anxiety involve the norepinephrine neurochemical system. The NET is a protein that plays a role in this system by shipping the chemical called norepinephrine back into neurons. The NET gene provides the instructions to make the NET. An on-off switch (promoter) in the NET gene determines how many NETs are made. Variation in the DNA sequence of the promoter may increase or decrease the number of NETs being produced. Since this may begin disease processes, the researchers studied the DNA sequence of the promoter. They found a big piece of DNA in normal people which had never been observed before. This DNA was found in two different sizes: one long and one short. When sufferers with the restricting type of anorexia nervosa, and their parents were tested, the parents were shown to pass on the long form significantly more often than the short form to their children. This shows that a person who inherits the long form has an increased chance of developing the restricting type of anorexia nervosa.

Keyword: Anorexia & Bulimia
Link ID: 2407 - Posted: 08.05.2002

Copyright © 2002 Scripps Howard News Service By LICIA ROCA, Sacramento Bee - P.J. Anderson is a napper. Three days a week she steals away from her office to catch a 10-minute afternoon snooze. "A power nap. That's what I call it," said Anderson, owner of OP Contract in San Francisco. "The reality is, I need to regroup a bit before I can put in a 10- or 12-hour day." Four years ago, Anderson saw her employees' fatigued faces and realized she wasn't the only one needing a break. She created a "wellness room" equipped with an alarm clock, daybed and blankets. Copyright © 2001 Nando Media

Keyword: Sleep
Link ID: 2406 - Posted: 06.24.2010

Copyright © 2002 AP Online By LISA RATHKE, Associated Press ESSEX, Vt. (- It's nearly as fast as the most advanced computer, but uses a fraction of the energy. It simultaneously zaps information to thousands of points and is equipped to correct itself. It's not made of silicon and it came long before the computer chip. It is the human brain. In searching for new ways to advance computers, engineers are looking to man's gray matter for inspiration. And while comparing the two, they often wonder why a computer can't act more like a brain. Copyright © 2001 Nando Media

Keyword: Robotics
Link ID: 2405 - Posted: 06.24.2010

Scientists are hopeful they can produce a drug to reduce the addictive effects of morphine, but keeping its painkilling properties. For years, researchers have been hunting a way to block the brain response which leads to dependence on morphine, and the street drug heroin, which works in a similar way. All attempts so far have failed, even if the addiction process was diminished, the drugs caused dangerous side-effects. However, now a research group from the National Institutes of Health (NIH), in the US, believe they have found another route to block addition. In mice, their method meant that much higher doses of the drug were needed before dependence started to emerge. However, an addiction researcher from the UK has warned that much more work will be needed before the principle can be turned into a drug for humans. (C) BBC

Keyword: Drug Abuse
Link ID: 2404 - Posted: 07.30.2002

MINNEAPOLIS / ST. PAUL--University of Minnesota researchers have found that a nontoxic bile acid produced in the body prevents apoptosis, or programmed cell death, in mice with Huntington's disease. This finding, to be published July 29 in the Proceedings of the National Academy of Sciences USA (PNAS), may eventually lead to a treatment for Huntington's disease (HD) in humans. HD is an untreatable neurological disorder caused by selective and progressive degeneration of neural cells. In the study, led by Walter Low, Ph.D., professor of neurosurgery in the university's Medical School, a dose of tauroursodeoxycholic acid (TUDCA) was administered subcutaneously once every third day for six weeks in mice with the HD gene. Researchers found TUDCA was able to cross the blood / brain barrier, something many molecules are unable to do, resulting in decreased apoptosis in the section of the brain affected by HD and improving the neurological cell function in the mice. "We're extremely encouraged by the neuroprotective function of TUDCA in Huntington's disease and will be examining its potential in future studies," said Low.

Keyword: Huntingtons
Link ID: 2403 - Posted: 07.30.2002

BALTIMORE, Md.--Traces of ordinary products, flushed and tossed away from millions of homes, gardens and garages, are likely more harmful to the sexual development and reproduction of fish in the Chesapeake Bay than scientists previously thought. The large, shallow Bay-average depth of less than 30 feet-with hundreds of tributaries, has long been considered by ecologists as a very favorable habitat for fish spawning, hatching and nurseries. However, today, at the annual meeting of the Society for the Study of Reproduction, at the Baltimore Marriott Waterfront Hotel, scientists of the University of Maryland Biotechnology Institute (UMBI) reported that the list of compounds in human pollution that can disrupt fish sexual hormones-a concern of scientists for the past 20 years-has widened considerably. Compounds in many detergents, plastics, pesticides, some medicines, and even thalates ("new car smell") disrupted the sexual development of juvenile zebra fish in experiments at UMBI's Center of Marine Biotechnology (COMB) in Baltimore.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 2402 - Posted: 07.30.2002

Orlando, FL -- Individual variation in response to medications remains a major problem within the healthcare system. In the United Kingdom, one in 15 British hospital admissions is due to adverse drug reactions; here in the United States, some 106,000 patients die and 2.2 million are injured each year by adverse reactions to prescribed drugs. A significant inter-individual variability can be found in clinical response during antipsychotic drug therapy. In the United Kingdom, up to 30 percent of patients respond inadequately to treatment for chemical imbalances in the brain. Some of the poor response can be can be attributed to poor patient compliance in taking the prescribed medication. However, alterations in genes encoding mediators of drug efficacy may be particularly important. This includes drug metabolizing enzymes, receptor targets, and transporters. These alterations may also be important for treatment-induced side effects Clozapine (trade name clozaril) is one of the newer antipsychotic medicines used to treat people with schizophrenia. Although clozapine is often more effective than other antipsychotic medicines, it is not suitable for everybody. Clozapine can cause a problem with the white blood cells of some people, and therefore patients take scheduled blood tests.

Keyword: Schizophrenia
Link ID: 2401 - Posted: 07.30.2002

Copyright © 2002 AP Online By LAURAN NEERGAARD, AP Medical Writer WASHINGTON - West Nile virus is sickening people far earlier this summer than usual, and is spreading so quickly - it's hit 33 states, as far west as South Dakota - that health officials believe it will reach California this year or next. Nobody knows how bad the mosquito-borne illness will get - although a rapidly growing outbreak among 32 people in Louisiana began a month earlier than West Nile has ever struck in this country, a big worry. But it's clear the virus first detected in New York City a mere three years ago has become a permanent summertime threat in most states. Yet it's fairly easy to prevent: Spray on DEET-containing mosquito repellent when you go outdoors, and don't let puddles collect in flower pots, wading pools or other spots where mosquitoes can breed. One specialist equates the safety steps to the routine of buckling a seat belt before driving. Copyright © 2001 Nando Media

Keyword: Miscellaneous
Link ID: 2400 - Posted: 06.24.2010

By ERIC NAGOURNEY Are some people just born more anxious than others? It is not that simple, but a new study suggests that inheriting a shorter version of a single gene appears to predispose people to fear. The study, reported in a recent issue of Science, looked at how people with different versions of the gene responded to pictures of people who appeared scared. Copyright 2002 The New York Times Company

Keyword: Emotions
Link ID: 2399 - Posted: 07.30.2002

By ERIC NAGOURNEY Two new studies report that from an early age, the brains and heads of autistic children develop differently from those of other children. But researchers said it was unclear what, if anything, might be learned from the findings. In separate studies appearing in the current issue of Neurology, Dr. Stephen R. Dager and Dr. Elizabeth H. Aylward, both of the University of Washington School of Medicine, found that brain growth in autistic children was more rapid in early years. Among the 3- and 4-year-old autistic children they examined, Dr. Dager and his colleagues found cerebral volumes that were on average 10 percent larger than they were in children with typical brain development. Copyright 2002 The New York Times Company

Keyword: Autism; Development of the Brain
Link ID: 2398 - Posted: 07.30.2002