Neuroscientists have not found any evidence that adult primates are able to create new neurons in the most sophisticated part of the brain, the neocortex, according to the results of a study published in the Dec. 7 issue of the journal Science. The results from scientists at Yale University and the University of Rochester run counter to a widely publicized report two years ago when other researchers reported the first discovery of neurogenesis ? formation of new neurons ? in the neocortex of adult monkeys. The new findings, in a study funded by the National Institutes of Health, come from David Kornack, assistant professor of neurobiology and anatomy at the University of Rochester, and his former adviser, neuroscience pioneer Pasko Rakic of Yale. ?As a neuroscientist, oftentimes the first question I?m asked when I meet someone is, ?How can I get more brain cells?? I?m as interested in the question as everyone else,? says Kornack. ?It?s now apparent that although some parts of the primate brain do acquire new neurons in adulthood, the neocortex is not among these regions.?

Keyword: Neurogenesis; Development of the Brain
Link ID: 1115 - Posted: 12.06.2001

By MARY DUENWALD The patient strapped to the hospital gurney, breathing through a respirator, is James, a 40-year-old man addicted to heroin. The anesthesiologist loads a syringe with 20 milligrams of naloxone and slowly injects it into the IV in James's right arm. During the next 10 minutes, the drug will enter his system, pry off the billions of opiate molecules that have been clinging to his brain cells and wash them away. This is a rather abrupt way to come off heroin. Were it not for the anesthesia holding him in a state of unconsciousness, James would be writhing, shivering, vomiting and perhaps screaming in pain. Even in his deep sleep, his heart rate and breathing speed up, his pupils dilate, his nose runs, his temperature rises, his arms and legs twitch sporadically and his skin erupts into gooseflesh. Over the course of the next four hours, as the opiates are flushed out through his liver and kidneys, his heart rate, breathing and temperature fall back to normal, his pupils readjust and his goose bumps recede. When he is awakened, his body is fully detoxified from heroin ? a process that can normally take days or even weeks. Copyright 2001 The New York Times Company

Keyword: Drug Abuse
Link ID: 1113 - Posted: 12.06.2001

Human brains are as varied as faces By Maggie Shiels in California A group of brain cartographers is creating the most detailed and sophisticated computer atlas of the human brain ever assembled. One of the things we have begun to learn from this map is that there are trends or patterns to brains that allow one to be sensitive to schizophrenia or Alzheimer's Arthur Toga, UCLA When the $15m (£10.6m) project is completed, the map will display the brain's anatomy and models of how it functions. "We don't understand the human brain in great detail yet," said Arthur Toga, director of the Laboratory of Neuro Imaging at the University of California in Los Angeles (UCLA), US. "The objective is to try to create a map that describes not only the brain's structure but its functions in a comprehensive way," he told BBC News Online. (C) BBC

Keyword: Brain imaging
Link ID: 1111 - Posted: 12.06.2001

Gaia Vince When the brain forms new short-term memories, it creates new neurons in a region of the hippocampus called the dendate gyrus. This process also clears outdated memories, making room for more new ones, say Joe Tsien of Princeton University, and his colleagues. Patients with Alzheimer's disease lose cells in the hippocampus, and one suggested treatment is to transplant stem cells into the region to replace the dead cells. But the new work suggests that the addition of new cells might in fact disrupt memory retention by dramatically altering connections between neurons in the hippocampus and boosting memory clearance, the researchers say. "The dentate gyrus is very small and so it has very limited memory storage capacity, but it is the only part of the brain where adult neurogenesis occurs," Tsien says. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 1110 - Posted: 12.06.2001

Claire Ainsworth The uniquely human habit of taking 18 years or so to mature is a recent development in our evolutionary history. Growth patterns of fossil teeth have shown that a prolonged growing-up period evolved long after our ancestors started walking upright and making tools. Our great ape relatives, the chimpanzees and gorillas, take about 11 years to reach adulthood. Scientists speculate that delaying this process allows children to absorb our complex languages, culture and family relationships. What's more, we need extra time for our large brains to grow - they are half as big again as those of the earliest humans, Homo erectus, who appeared some 2 million years ago. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Sexual Behavior
Link ID: 1109 - Posted: 12.06.2001

James Randerson It is being hailed as one of the most significant advances in nerve regeneration in a decade. After severing an optic nerve in rats, neurologists have found a way to reconnect it to the brain so that it once again transmits normal electrical signals. The achievement is a first in mammals, and may hint at ways of reversing some types of blindness in people. Scientists also hope to use a version of the technique to treat people with spinal cord injuries. In many simple creatures, damaged nerves mend themselves. But mammals, with their large brains, have traded this flexibility for stability. With such a complex nervous system, rewiring damaged nerves the wrong way could do more harm than not rewiring at all. So mammals keep a lid on nerve cell growth by producing proteins that inhibit axons--the part of a nerve cell that conducts signals--growing in the scar tissue that forms after injury. © Copyright Reed Business Information Ltd.

Keyword: Regeneration; Vision
Link ID: 1107 - Posted: 12.06.2001

Copyright © 2001 AP Online E-mail this story By LINDSEY TANNER, Associated Press CHICAGO - Yet another experimental stroke drug that once showed great promise in animals has failed in humans, with the study cut short because patients were dying or showing no improvement. The study involved aptiganel, or Cerestat, which is part of a once-promising class of experimental drugs known as neuroprotective medicines. Neuroprotective medicines have been a disappointment so far, but the study's author said researchers have not abandoned hope for the drugs. In the latest study, researchers looked at 628 stroke patients at 156 medical centers in the United States and five other countries. Copyright © 2001 Nando Media

Keyword: Stroke
Link ID: 1104 - Posted: 12.05.2001

By JANE E. BRODY Cindy Brody, my sister-in-law, was only 40 when she realized that something bad was happening to her ability to hear. Telephone conversations were a challenge and there were lots of misunderstandings even during one-on-one conversations, including those with her husband at the dinner table. But the day of reckoning came when she heard a riding instructor say "to hell with her" about a disabled woman who wanted to ride a horse, when in fact the man had said "I'm helping her." So she went to an audiologist to have her hearing checked. Sure enough, she had suffered a significant hearing loss in her left ear and some loss in the right ear as well. The audiologist said she could be helped by a hearing aid, and after several adjustments she is now using the aid successfully. Copyright 2001 The New York Times Company

Keyword: Hearing
Link ID: 1103 - Posted: 12.05.2001

A protein linked to accumulation of harmful brain plaque in Alzheimer?s patients has been shown in fruit flies and mice to be an important part of a molecular transportation system that moves signals and vital protein cargoes within the brain. In addition, researchers have determined that the protein, called amyloid precursor protein (APP), can induce a biochemical process that clogs brain traffic lanes and eventually leads to neuron cell death. The findings are the first scientific data that describe the transport role of APP and that offer a new hypothesis linking the protein?s cellular trafficking function to the formation of harmful plaque deposits called amyloid beta in the brains of Alzheimer?s victims. Conducted in the lab of senior author Lawrence S.B. Goldstein, Ph.D., the studies were published in the Nov. 8, 2001 issue of the journal Neuron and the Dec. 6, 2001 issue of the journal Nature.

Keyword: Alzheimers
Link ID: 1100 - Posted: 12.05.2001

Honeycomb geometry helps dancing bees gather an audience. ERICA KLARREICH If you want to catch someone's attention on the dance floor, it helps if you're dancing on a honeycomb. Vibrations from a dancing honeybee are naturally amplified by the hexagonal comb, a new study finds1. The work may explain how bees attract observers to the intricate dances that tell them where to find distant food sources. It could also help architects understand how to build earthquake-proof buildings. The waggling dance of forager bees is "one of the most spectacular forms of animal communication," says Thomas Seeley, who studies bees moving and shaking at Cornell University in Ithaca, New York. A single dance can convey the location of a field of flowers as far as 10 kilometres away. Tautz, J. et al. Phase reversal of vibratory signals in honeycomb may assist dancing honeybees to attract their audience. J. Exp. Biol, 204, 3737 - 3746, (2001). © Nature News Service / Macmillan Magazines Ltd 2001

Keyword: Animal Communication
Link ID: 1096 - Posted: 12.03.2001

US scientists have found that taking the drug methamphetamine - or "Ice", can damage the brain and increase the risk of Parkinson's Disease. Scientists from the US Department of Energy found that people who abuse the drug have fewer receptors for dopamine, the brain chemical associated with pleasure. Meth abusers would be predisposed to such neurodegenerative disorders as Parkinson's Disease Nora Volkow, lead researcher In an article in the American Journal of Psychiatry, they suggest that this can reduce the ability of users to 'say no' to the drug and may explain why they become addicts. However, in a follow-up study, published in The Journal of Neuroscience, they suggested this damage can be reversed if users abstain from the drug. (C) BBC

Keyword: Drug Abuse
Link ID: 1094 - Posted: 12.03.2001

Science prompts a shift in cultural attitude toward which hand we favor in life By Marcia Mattson Times-Union staff writer Not so long ago, left-handers had it rough. Considered evil, awkward, unhygienic or mentally retarded, children who showed signs of left-handedness were beaten. Their left hands were tied behind their backs or slapped with rulers so they would have to use their right hand. Today, scientists are coming closer to explaining the biological reasons for left-handedness. And society is shedding its biases and growing more accommodating of left-handers, who make up about 10 percent of the U.S. population. But it's still a right-hander's world, says Jane M. Healey, a child neuropsychologist, professor and left-hander. So parents can take simple steps from the moment their toddler grips a spoon in his pudgy left fingers to help him succeed. © The Florida Times-Union

Keyword: Laterality
Link ID: 1092 - Posted: 12.03.2001

The latest in a series of studies on secretin has failed to show that giving the digestive hormone to children with autism alleviates symptoms of the disorder, according to a study funded by the National Institute of Child Health and Human Development. The study, which appeared in the November 2001 issue of the Journal of the American Academy of Child and Adolescent Psychiatry , found that patients with autism who received a form of the hormone derived from swine showed no statistically significant improvements in the core symptoms of the disorder when compared to when the same patients received a placebo. (The core symptoms of autism involve social and communications skills.) In certain secondary measures of autism, patients receiving secretin also showed no improvement when compared to when they received a placebo. The researchers used porcine secretin, a form of the hormone derived from pigs, and the form most commonly used in diagnostic tests of the digestive system. Previous studies have also tested laboratory manufactured secretin as a treatment for autism. The current study tested porcine secretin to rule out the possibility that the naturally occurring form of the hormone might have a different effect than does the synthetic version.

Keyword: Autism; Development of the Brain
Link ID: 1091 - Posted: 11.30.2001

A series of fact sheets describing the latest research findings on autism is now available from the National Institute of Child Health and Human Development (NICHD). "We have a strong responsibility to tell the public about the results of our intensive research programs," said Duane Alexander, M.D., Director of the NICHD and co-chair of NIH's Autism Coordinating Committee. "These fact sheets will make NICHD's autism research much more accessible to those who need it." At least one in 500 people are affected by some form of autism, a neurodevelopmental disorder that affects early brain development, resulting in communication problems, difficulty with normal social interactions, and a tendency to repeat specific patterns of behavior. Because these symptoms and behaviors can vary greatly among patients, doctors consider autism to be a "spectrum" disorder--a group of disorders with similar features. Although there is no cure for autism yet, educational, behavioral, and drug treatments have been designed to ease specific symptoms of the condition.

Keyword: Autism
Link ID: 1090 - Posted: 11.30.2001

Scientists at the University of California, San Diego have produced dramatic images of brain cells forming temporary and permanent connections in response to various stimuli, illustrating for the first time the structural changes between neurons in the brain that, many scientists have long believed, take place when we store short-term and long-term memories. In a paper published in the November 30 issue of the journal Cell, researchers from UCSD's Divisions of Biology and Physical Sciences describe their achievement, a "Holy Grail" for neuroscientists who have long sought concrete evidence for how nerve connections in the brain are changed temporarily and permanently by our experiences. "The long-term memories stored in our brain last our entire lives, so everybody had assumed that there must be lasting structural changes between neurons in the brain," says Michael A. Colicos, a postdoctoral fellow at UCSD and the lead author of the paper. "Although there's been a lot of suggestive evidence to indicate that this is the case, it's never before been directly observed." Copyright ©2001 Regents of the University of California. All rights reserved.

Keyword: Learning & Memory
Link ID: 1089 - Posted: 11.30.2001

For a lobster living on the ocean floor, the chemical trails left by prey, predators, mates and competitors must make a confusing tangle ­ each filament of odor intertwining with the others until discovering the source of any one of them starts to seem as impossible as untangling a ball of liquid yarn. But somehow the lobster does it, and a new study by researchers at Stanford, the University of California-Berkeley and Bowling Green State University has brought scientists one step closer to understanding how. The study focused on the Caribbean spiny lobster, Panulirus argus, which uses its two olfactory antennules ­ 6-centimeter-long antennae covered with arrays of odor-sensitive hairs ­ to sniff out odors. The findings, which will be published in the journal Science on Nov. 30, could help engineers design robots that can follow chemical trails underwater, a process known as plume tracing.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 1088 - Posted: 11.30.2001

By Denise Freitag, Staff Reporter For Meaghann Muncy, her nine-year struggle with seizures may have started in the womb. Though her mother, Sandy Muncy, noticed something was wrong at about six months, the Dillsboro Elementary School third-grader was not diagnosed until she was 3 1/2 with a rare birth defect. After years of trying medicines and treatments to bring the seizures under control, surgery appears to be the only option left. The problem is Meaghann?s family does not have enough money to have the procedure done at the hospital best qualified to give her a shot at a normal life. The result is the formation of Meaghann?s Fund to raise the estimated $150,000 needed to send her to Johns Hopkins Medical Center in Baltimore. When Meaghann was young it was hard to tell what was wrong. She did not have the type of seizures most people expect in which someone falls to the floor shaking, said Muncy. Copyright © 1995 - 2001 PowerAdz.com LLC. All Rights Reserved.

Keyword: Epilepsy
Link ID: 1086 - Posted: 11.30.2001

Study shows brain scan detects patterns of neural activity when someone lies Carl T. Hall, Chronicle Science Writer Going the polygraph one better, scientists say they have spotted a telltale pattern of brain activity that can reveal when someone is lying. The new study shows that a brain-scanning method known as functional MRI -- which has already been used to capture images of such elusive mental states as romantic love and cocaine cravings -- also can snag a liar. The discovery suggests police interrogators may someday be able to get a more direct view when devious wheels start turning in the minds of suspects. Some experts on lying said they would welcome a better lie-detection tool, while others said it raised serious privacy concerns. "It's kind of a scary idea," said Stanford University neurobiologist Ben A. Barres. "Right now, nobody takes lie detectors all that seriously." ©2001 San Francisco Chronicle Page A - 10

Keyword: Stress; Brain imaging
Link ID: 1084 - Posted: 11.29.2001

By RANDI HUTTER EPSTEIN [F] or many people who have had coronary artery bypass surgery, regaining emotional strength is a tougher challenge than recuperating physically. Traditionally, rehabilitation specialists working with bypass patients have focused on rebuilding weakened muscles after surgery. But recently, a few teams of cardiac specialists ? nurses, doctors and psychologists ? have begun to concentrate on the mental fatigue and overwhelming sadness that strike many patients. There are no conclusive statistics about the incidence of depression after bypass surgery. Estimates vary widely from fewer than a third of patients to more than three-quarters. Some experts believe that the rate of depression after bypass surgery is much higher than that of other types of surgery, but not everyone agrees. Copyright 2001 The New York Times Company

Keyword: Depression
Link ID: 1081 - Posted: 11.29.2001

by Emily Carlson Gender hormones may be a key factor in the onset of a common human disorder called sleep apnea, suggest findings from a new study by researchers at the School of Veterinary Medicine. Sleep apnea, which typically occurs when the tongue blocks the airway during sleep, affects more than 18 million Americans, a majority of whom are middle-aged men. UW-Madison scientists Andrea Zabka and Mary Behan studied how age affects a female rat's response to hypoxia, or oxygen deprivation, and compared the results to those from a previous study focusing on male rats' responses. The gender-specific responses, they found, are completely different. In the earlier study published last summer, the researchers deprived male rats of oxygen for brief periods and then monitored nerve activity from the brain to the tongue and diaphragm, two major muscles involved in respiration. The results showed that young and middle-aged rats reacted differently to hypoxia. Copyright © 2001 The Board of Regents of the University of Wisconsin System.

Keyword: Sleep; Hormones & Behavior
Link ID: 1080 - Posted: 11.29.2001