Although a summertime chorus of frogs may sound like rhythmic cacophony, the nerve cells in each amphibian are decoding important messages. According to a new study, frogs can count the number of times a burst of sound is repeated in a call, an ability that researchers say helps them recognize friends and foes. The results, published in the 3 September online issue of Nature Neuroscience, also might help elucidate how humans understand speech. In many frog species, males communicate using sound bites interspersed with regular pauses, such as the brief silence between "rih" and "bit." The length of the pause is full of meaning; male Pacific tree frogs, for example, use a slow call to intimidate other males and a fast trilling to attract females. Several years ago, researchers discovered individual nerve cells in the frogs that would fire in response to simulated frog calls of different lengths. In the current study, neuroethologist Gary Rose of the University of Utah, Salt Lake City, and colleagues wanted to determine what components of the sound the neurons were paying attention to. Copyright © 2002 by the American Association for the Advancement of Science.

Keyword: Hearing; Sexual Behavior
Link ID: 2586 - Posted: 06.24.2010

DALLAS –– Researchers at UT Southwestern Medical Center at Dallas have identified one of the key proteins involved in the establishment of the central nervous system. The researchers found that the protein, SynCAM, plays a major role in the formation of synapses, which are specialized junctions at which a neuron communicates with a target nerve cell. Neurons receive and send electrical signals over long distances within the body. The process of synaptic transmission drives communication between neurons in the brain and underlies all brain function. This is only the second study that cites the initial events leading to the formation of synapses in the central nervous system, said Dr. Thomas Biederer, a postdoctoral researcher in the Center for Basic Neuroscience and lead author of the study, reported in the Aug. 30 issue of Science. © 2002 The University of Texas Southwestern Medical Center at Dallas

Keyword: Development of the Brain; Learning & Memory
Link ID: 2585 - Posted: 06.24.2010

Fossil infant skeleton could shed light on hominid development. TOM CLARKE A skeleton of a newborn Neanderthal, lost for almost 90 years, has turned up in a museum in France. The beautifully preserved fossil could lead to new insights into the evolution of human development and the relationship between modern humans and our long-extinct cousins. The fossil - of a baby just four months old - is called 'Le Moustier 2' after the town in southwestern France where it was discovered in 1914. The infant's short life ended around 40,000 years ago. "It's a very important fossil," says Bruno Maureille of the University of Bordeaux in France. Remains of only five other infant Neanderthals have ever been found. © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Evolution
Link ID: 2584 - Posted: 06.24.2010

That spontaneous serenade from the zebra finch is not only more rehearsed than cellist Yo-Yo Ma's chamber music, but the bird even keeps its "finger" on its mental sheet music both day and night. In a National Science Foundation (NSF) supported study at Lucent Technology's Bell Laboratories, researchers have discovered that signals serving as "mental pointers" are produced in the brains of zebra finches while they sing, and also while they dream about, or "rehearse," their song during sleep. This long-term, fundamental neural research is helping scientists understand brain mechanisms and, specifically, how the brain produces signals for motor control and learning. By studying how songbirds learn their songs, scientists hope to understand how humans learn to speak. The finch's brain "circuits" are similar to the parts of the human brain that handle motor control and learning despite the obvious size difference.

Keyword: Hearing; Learning & Memory
Link ID: 2583 - Posted: 09.05.2002

Pheromones - chemical signals that influence social and reproductive behaviors - have been studied since the 1950s, but the molecules in the mammalian nervous system that actually detect pheromones have remained elusive. Now, a team of researchers, led by The Rockefeller University's Peter Mombaerts, M.D., Ph.D., provides the first functional evidence for molecular receptors for pheromones in mammals. Their findings contribute to our understanding of the functioning of the brain in orchestrating social and reproductive behavior. They also may help explain why sexual reproduction typically occurs only within a species and, ultimately, how species form. In the Sept. 5 issue of the journal Nature, Mombaerts and colleagues at Rockefeller, University of Maryland School of Medicine and Monell Chemical Senses Center report significantly less aggressive and sexual behavior in laboratory mice who were engineered to lack a particular cluster of genes that previous research from the Rockefeller lab had linked to pheromone detection. They also show that the nerve cells of mutant mice are unable to detect certain pheromones. These pheromone receptors are found in the lining of the animals' vomeronasal organ (VNO), a part of the olfactory system thought to be specialized in the detection of pheromones.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 2582 - Posted: 09.05.2002

By Amy Raisin, Staff Writer VALENCIA -- The X-ray looks like a hoax image found on some Internet site, but the 3 1/4-inch nail lodged in Jorge Hernandez's brain was no laughing matter. One look at the entry wound just below Hernandez's right nostril and the massive incision on his forehead held together by fresh sutures shows just how close a call he had. "I am very lucky. I'm just thankful that everybody was here to help me so much," Hernandez said Wednesday as he was being released from the hospital five days after surgery. Dr. Rafael Quinonez, the neurosurgeon at Henry Mayo Newhall Memorial Hospital who removed the nail, said Hernandez was a lucky man indeed. Copyright © 2002 Los Angeles Daily News

Keyword: Brain Injury/Concussion
Link ID: 2581 - Posted: 06.24.2010

When the dust settles after a traumatic event, some people experience a condition marked by intense anxiety, known today as post-traumatic stress disorder. Researchers have recently started to look at the ailment on a biological level and found evidence that it's rooted in the brain, arising from a complex interaction of several chemical and brain area changes. The findings highlight the seriousness of the condition and may lead to new treatments that could help the more than 5 million Americans estimated to have the disorder during the course of a given year. A plane crashes. Fires erupt. Walls tumble down. You escape the chaos physically unscathed, but how's your brain? For years, many doctors believed that people who experienced an extraordinarily traumatic or life-threatening event such as a terrorist attack, war or natural disaster should be able to tough it out and move on. Some individuals, however, found that these events stuck with them. They relived the experience through nightmares and flashbacks; had trouble sleeping; and felt detached, depressed and anxious. Today, increasing research indicates that the effects, now collectively referred to as posttraumatic stress disorder (PTSD), are not some sign of a weak personality, but the result of troubles in the brain. Copyright © 2002 Society for Neuroscience

Keyword: Stress; Learning & Memory
Link ID: 2580 - Posted: 06.24.2010

In a feat nowhere near as terrifying as the movie Jurassic Park, scientists have reconstructed a light-sensing protein from the ancestors of dinosaurs. It suggests that dinosaurs may have been well-adapted to seeing in the dark. Biologists are excited by the promise of the technique, which predicts the structure of proteins from extinct animals by studying those of living relatives--then brings the protein to life. Paleontologists learn about extinct animals in two main ways. They study fossils, and they make educated guesses based on existing creatures. Although neither method provides direct information about the molecular inner workings of the animals, inference is rapidly becoming more sophisticated. An intriguing prospect is the comparison of gene sequences to reconstruct molecules. But many scientists suspected this exercise would merely be computer-generated speculation. Now, molecular biologist Belinda Chang of Rockefeller University in New York City and colleagues have dispelled those doubts. Using the gene sequences that code for the visual protein rhodopsin in 30 living vertebrates, such as alligators, chickens, and more primitive vertebrates such as lampreys, the researchers reconstructed the rhodopsin belonging to the archosaurs. This ancient group gave rise to dinosaurs, as well as extant groups such as crocodiles and birds. Chang's team used a statistical method, known as maximum likelihood, that identifies the series of changes most likely to have generated the observed range of modern proteins and extrapolates the most likely common ancestor--the archosaur protein. Copyright © 2002 by the American Association for the Advancement of Science.

Keyword: Vision; Evolution
Link ID: 2579 - Posted: 06.24.2010

Parkinson's effects brain connections Researchers at Rutgers, The State University of New Jersey, have discovered critical clues that may explain why parts of the brain damaged by Parkinson's disease, specifically those that control sensory-guided movements, aren't repaired by dopamine replacement therapy. Parkinson's is the second most common neurodegenerative disease affecting older people in the United States and is characterized by a loss of dopamine in the basal ganglia portion of the brain. "Our research indicates that the loss of dopamine seems to cause connections in the brain to reorganize. This affects the brain's ability to communicate effectively with body parts, for example, the ability to respond to stimuli from the body in order to control body movements," explained Mark West, a behavioral neuroscientist and professor in the department of psychology at Rutgers' Faculty of Arts and Sciences-New Brunswick.

Keyword: Parkinsons
Link ID: 2578 - Posted: 09.04.2002

Obsessive-Compulsive Disorder (OCD) is a severe psychiatric condition affecting up to 3% of the general population lifetime. It is characterized by intrusive unwanted thoughts (obsessions) and the need to perform repetitive acts or rituals in order to alleviate the anxiety (compulsions). As an example, a patient who fears contamination would be afraid of touching anything and would feel that they must wash their hands over and over. The causes of OCD remain obscure. However, there is strong evidence for a genetic component (the risk of developing OCD is higher in the relatives of affected), and for the involvement of the serotonin (5HT) neurochemical system. Serotonin is a neurotransmitter that is essential for communication between cells, and it is possible that the receptors that tell how much serotonin should be released may be altered in OCD patients.

Keyword: OCD - Obsessive Compulsive Disorder; Genes & Behavior
Link ID: 2577 - Posted: 09.04.2002

Giving smokers medication to mimic an increase in their brain's level of a substance called dopamine could help squelch their desire for cigarettes, according to a new study. Researchers examined 20 heavy smokers who were given two drugs that either increased or decreased the brain's level of dopamine, a neurotransmitter that affects motor function. Dopamine, a chemical in the central nervous system, is believed to affect emotion, and research on animals has shown that nicotine causes a release of dopamine in brain areas that are associated with feelings of pleasure. Test subjects smoked less when given a drug that mimics the effects of dopamine in the brain than they did when given a second drug that impedes dopamine's effects. When the subjects were given the dopamine-mimicking drug, their desire to smoke dropped, but when the same smokers were given the dopamine-impeding drug, they took longer and more frequent puffs of smoke.

Keyword: Drug Abuse
Link ID: 2576 - Posted: 09.04.2002

By JANE E. BRODY Susan McGee of Bethesda, Md., and Jane Quinn of Brooklyn were not planning to take hormones at menopause. But after many months of sleep disrupted nightly by drenching sweats and changes of bedclothes, they gave in. Ms. McGee said she became so sleep deprived that she could hardly do her job and feared falling asleep while driving. Ms. Quinn found it increasingly difficult to concentrate on her work, became uncharacteristically irritable and began to think she was losing her mind. The hormones quickly restored their sleep and their sanity. These two are among millions of American women near, at or beyond menopause who are asking why so much remains unknown about a drug that has been on the market for 60 years, and what they should make of new findings that are surprising and disappointing proponents of hormone replacement therapy, or H.R.T. Copyright 2002 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 2575 - Posted: 09.03.2002

By SANDRA BLAKESLEE As hunting season approaches, people in Wisconsin and the Rocky Mountain states are increasingly worried about chronic wasting disease, the variant of mad cow disease that afflicts deer and elk. Scientists are fairly confident that no one in the United States has died from a human version of chronic wasting disease, but hunters are confused and frightened anyway. In Wisconsin in the past six months, 24 white tail deer have tested positive for the disease, and none of them looked sick. Not certain if venison frozen from last year's hunt is safe to eat, many families are throwing it away. Copyright 2002 The New York Times Company

Keyword: Prions
Link ID: 2574 - Posted: 09.03.2002

Some researchers believe that sleep helps learning By Harvey Black Most people require sleep to face tomorrow with a clear head. But clarity of mind may be just one reason why slumber is needed; a growing body of research suggests that sleep aids learning. It is a view not universally held, but supporting evidence appears to be growing. "We just don't know right now if it will turn out to be true. There is so much data coming out now," says Pierre Maquet, senior research associate, National Fund for Scientific Research, University of Liege, Belgium. "These data are coming from a wide variety of species, techniques, experimental paradigms. There is something behind it." Daniel Margoliash, professor of organismal biology and anatomy, University of Chicago, says, "A substantial percentage of the scientific population ... is still quite skeptical." Researchers have data supporting the link between sleep and memory from studies with humans, rats, and birds, in which the subjects perform numerous learning tasks.1 The studies focus on two specific parts of sleep--slow wave sleep (SWS) and rapid eye movement (REM) sleep. SWS is deep slumber marked by large-amplitude electroencephalogram (EEG) patterns. REM is characterized by high-frequency, low-amplitude EEGs and decreased muscle tone. These stages appear to have two different functions, says Robert Stickgold, assistant professor of psychiatry, Harvard Medical School. SWS strengthens memories or connections already in progress, but it does not help connect memories to one another. "I think REM sleep is going to turn out to be most relevant to ... associative and connective processes in memory," he says. A GOOD NIGHT'S LEARNING Matthew Wilson, associate professor in the Center for Learning and Memory at the Massachusetts Institute of Technology, studies the relationship between maze learning and sleep. He found that the hippocampus, a brain structure involved in spatial learning, appears to show the same activity pattern during sleep as when animals learn the maze.2 After research subjects awoke from SWS, their hippocampi retrieved recently acquired memory, Wilson says, witnessed at the level of patterns in the hippocampi's neurons. "One could describe what goes on in slow wave sleep as a replay of recent experience." ©2002, The Scientist Inc.

Keyword: Sleep; Learning & Memory
Link ID: 2573 - Posted: 06.24.2010

Pope John Paul II has been prescribed an experimental treatment made from a tropical fruit to ease symptoms of Parkinson's disease, it is reported. The French paper Le Monde reports that the treatment, an extract of fermented Asian papayas, was suggested by a French doctor, who met the 82-year-old Pontiff in June. Dr Luc Montagnier actually met the Pope to try to persuade him to relax the Catholic Church's stance on the use of condoms as a way to tackle Aids in the developing world. However, Dr Montagnier, who co-discovered the Aids virus, also used the meeting to propose the papaya treatment for the Pope, whose symptoms include a hand tremor and slurred speech. (C) BBC

Keyword: Parkinsons
Link ID: 2572 - Posted: 09.02.2002

The device may end the need for a skin prick test Scientists are developing a smart tattoo that could tell diabetics when their glucose levels are dangerously low. Once perfected, the tattoo will allow glucose levels to be monitored round the clock, and could allow an alarm system that would warn the diabetic if their glucose levels were to fall dangerously. It would also mean that diabetics would no longer have to subject themselves to the finger-stick devices that currently they must use every day. The tattoo has been designed Gerard Cote, of Texas A&M University, and Michael Pishko, of the chemical engineering department at Penn State University. It is made of polyethylene glycol beads that are coated with fluorescent molecules. Because glucose displaces the fluorescent molecules, the level of fluorescence is high when bodily glucose levels are low. Fluorescence levels could be measured using a device, such as a watch, that could also give users a readout of their glucose level. (C) BBC

Keyword: Obesity
Link ID: 2571 - Posted: 09.02.2002

By ANAHAD O'CONNOR Dr. Sanford L. Palay, a neuroscientist who helped uncover the detailed anatomy of the nerve cell and obtained the first images of the synapse and the structures that release messenger chemicals in the brain, died Aug. 5 at a hospital in Concord, Mass. He was 83. The cause was kidney failure, a family member said. In 1953, while conducting research at Rockefeller University in New York, Dr. Palay used the recently invented electron microscope to study the synaptic vesicles that transmit nerve impulses. His paper "The Fine Structure of Neurons" and his later research helped change thinking on nerve functions. Copyright 2002 The New York Times Company

Keyword: Evolution
Link ID: 2570 - Posted: 09.02.2002

A freak accident left Blake Harper paralyzed and bankrupt. But he vows to make a comeback. Mike Roberts The Province A few days after his first birthday in a wheelchair, 29-year-old Blake Harper will crawl into Okanagan Lake and attempt to swim a two-kilometre stretch of the lake's choppy waters. A sadder sight will not be seen on the lake that day -- a young man dragging his useless legs through the water while on the shore his friends cheer and his mom and sister sob for they don't know what: joy that he's so alive; sadness that he's so irreparably damaged. Before he joined the Spinal Cord Injury Club of Canada last spring (36,000 members and growing), Blake Harper was a strapping young carpenter, a natural bodybuilder who loved extreme sports, liked to travel and dreamed of one day opening his own scuba shop. © Copyright 2002 The Province

Keyword: Movement Disorders; Regeneration
Link ID: 2569 - Posted: 06.24.2010

LeRoy Hunter says in his family, falling down was a serious concern By Tyler Vincent, The Journal-Standard FREEPORT - Growing up with a mother afflicted with amyotrophic lateral sclerosis, or Lou Gehrig's disease, is bound to have an effect on a young man's outlook on life. Certainly that was the case for Freeport resident LeRoy Hunter, who reflects on those memories in his home office, in front of his walker that he has used for the last two years. Hunter, who was diagnosed with ALS in 1995, will be appearing on the Rockford edition of the Jerry Lewis Labor Day Muscular Dystrophy Association Telethon, which began Sunday night and runs through Labor Day. Copyright © 1995 - 2002 PowerOne Media, Inc. All Rights Reserved.

Keyword: ALS-Lou Gehrig's Disease
Link ID: 2568 - Posted: 06.24.2010

A row has erupted after three experts suggested that Ecstasy may not be dangerous and that people are being misled about the drug. The psychologists have strongly criticised animal and human studies which say the drug causes long-term brain damage and mental problems. But other scientists insist the harmful effects of Ecstasy are undeniable. Writing in the magazine The Psychologist, published by the British Psychological Society, the researchers say the drug's reported adverse effects may even be imagined because of the belief that the drug causes long-term harm. © Copyright Press Association Ltd 2002, All Rights Reserved.

Keyword: Drug Abuse
Link ID: 2567 - Posted: 06.24.2010