Whales give away their predatory intentions. TOM CLARKE Harbour seals can distinguish between the sounds of friends and foes. The mammals flee at the sound of distant chatter between killer whales with a taste for seal blood, but continue to feed when fish-eating killer whales converse nearby, new research shows1. "We assume a lot of intelligence from whales," says Volker Deecke, who led the study. "This shows that seals are quite bright little animals too." Deecke's team watched wild harbour seals near Vancouver, Canada, respond to various recordings of killer whales' calls broadcast underwater. Killer whales cruise America's Pacific Northwest. Some live in large family groups along the coastline, feeding exclusively on fish. Others patrol hundreds of miles of coast in smaller packs, hunting harbour seals. © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Animal Communication; Hearing
Link ID: 3004 - Posted: 06.24.2010

by Tabitha M. Powledge S researchers have identified two key enzymes in the brain that allow chronic pain to persist despite treatment. The finding for the first time offers the brain as a possible target for therapy. Most approaches for pain relief have focused on peripheral nerves and the spinal cord. But while researchers have thought of the brain as the reporter of pain, it is actually the amplifier and even the interpreter of pain, says Min Zhuo, professor of neurobiology at Washington University in St. Louis. "So we have to fix the interpreter, not just try to stop the activity coming in," he said. Using knockout mice, Zhuo and his colleagues provide genetic, pharmacological, and behavioral evidence that two enzymes - adenylyl cyclase 1 and 8 - acting chiefly in the forebrain, are important for synaptic potentiation and behavioral sensitization after tissue injury and inflammation. © Elsevier Science Limited 2002

Keyword: Pain & Touch
Link ID: 3003 - Posted: 06.24.2010

Study Shows Risks Include Diabetes, Carpal Tunnel Syndrome By Marc Kaufman Washington Post Staff Writer Injections of human growth hormone, which have become increasingly popular as a virtual "fountain of youth," do reverse some of the common physical attributes of aging, a new federally sponsored study has found. But the shots also have potentially serious side effects, including increasing the risk of developing diabetes and carpal tunnel syndrome. In the most extensive clinical trial so far of the hormone -- which is available at the many "anti-aging" clinics opening around retirement centers -- researchers concluded that the growth hormone treatment was not ready for widespread use, although it showed a "promising" ability to increase muscle and decrease fat in older people. "There may be benefits to some older people in the use of growth hormone, but the safety is not established, and it should only be used in controlled trials," said Marc R. Blackman of the National Institutes of Health, who led the study. "This is not ready for prime time." © 2002 The Washington Post Company

Keyword: Hormones & Behavior
Link ID: 3002 - Posted: 06.24.2010

DALLAS – – Scientists at UT Southwestern Medical Center at Dallas have unraveled a mysterious connection – a potential mechanism that links brain injuries in infants to an infection in the mother’s placenta. Their findings, published in the October edition of Pediatrics, could eventually lead to diagnostic tests for infants and mothers that could help prevent brain injury. “The most critical issue in preventing and treating brain injury in infants is figuring out where the damage begins and what triggers it,” said Dr. Jeffrey Perlman, professor of pediatrics at UT Southwestern and senior author of the study. “Our study opens a new pathway of understanding, but we still don’t have all the answers.” © 2002 The University of Texas Southwestern Medical Center at Dallas

Keyword: Development of the Brain
Link ID: 3001 - Posted: 06.24.2010

Magnetic bracelets do not provide relief from muscle or joint paint, according to doctors. Research carried out in the United States suggests ionized bracelets are no more effective than 'dummy' versions. Manufacturers and some users claim the jewellery provides relief for conditions like arthritis and migraines through magnotherapy. They claim that an electric current produced by the bracelet improves the circulation of the blood and helps to boost general health. Dr Robert Bratton and colleagues at the Mayo Clinic in Jacksonville Florida decided to test those claims. They gave one group of 305 people ionized bracelets which they wore for 28 days. (C) BBC

Keyword: Pain & Touch
Link ID: 3000 - Posted: 11.13.2002

By GINA KOLATA Over the past few years, hundreds of clinics have sprung up, providing human growth hormone to thousands of elderly people looking for a fountain of youth. Athletes, would-be athletes and bodybuilders also take it, often in huge amounts, hoping to build muscle. But there has been almost no objective evidence on whether it works. Now, in one of the largest and most careful studies so far of human growth hormone in healthy older people, researchers find that it can markedly transform older people's bodies. The effects were potent. Those who took the drug gained lean body mass, much of which is likely to be muscle, and lost fat as if they had been working out in a gym, lifting weights and doing aerobic exercise. Some men gained 10 pounds of lean body mass and lost an equivalent amount of fat. Yet the subjects, who ranged in age from their mid-60's to their late 80's, were sedentary and did not exercise or change their diets. But the investigators caution that these gains were accompanied by serious adverse side effects in nearly half the subjects, who developed pre-diabetes or diabetes, aching joints and swollen tissues. Copyright The New York Times Company

Keyword: Hormones & Behavior
Link ID: 2999 - Posted: 11.13.2002

Nitric oxide (NO), the 1998 Nobel Prize-winning wonder gas, plays a central role in just about every physiological process in the human body. One of its functions is to dilate blood vessels in order to regulate blood pressure. Now, a new study shows that NO's cardiovascular role holds the key to the long-mysterious pain associated with sickle-cell anemia, along with a possible antidote. People with sickle-cell anemia have a genetic mutation that causes hemoglobin to crystallize inside their red blood cells. The sharp hemoglobin molecules weaken the membranes, causing the cells to rupture. Up to 10% of all red blood cells can burst in a single day, dumping hemoglobin into the blood stream. This somehow constricts the blood vessels and causes intense pain. Until now, however, the chain of events wasn't known. Copyright © 2002 by the American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 2998 - Posted: 06.24.2010

Levels of testosterone during pregnancy appear to influence the gender-role behavior of preschool girls, according to a new study. Researchers measured pregnant women's levels of testosterone, then evaluated the behavior of their children at age 3 1/2. The greater the maternal testosterone level, the more likely girls were to engage in "masculine-typical" gender-role behavior, such as playing with toys typically preferred by boys. No correlation was found for boys' behavior, however. The researchers based their hypotheses on animal studies that have shown a correlation between maternal levels of testosterone and behavior in female offspring.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 2997 - Posted: 11.13.2002

First risk gene for schizophrenia found in the general population by Jessica Whiteside -- Scientists at U of T have discovered the first "risk gene" for schizophrenia found in the general population. An uncommon variation of a gene called Nogo, when inherited from both parents, increases the risk of developing schizophrenia, says a study to be published in Molecular Brain Research Nov. 15. Previous findings about other risk genes for the disease were restricted to specific ethnic groups. "Finding a risk gene in the general population - the first finding of this type internationally - opens the door to discovering new and related risk genes. Now scientists will know where to look for related genes," says pharmacology and psychiatry professor Philip Seeman. "This will help in diagnosis and potentially in the design of new medications for treatment of this terrible disease," adds Seeman who worked on the study with psychiatry professor Teresa Tallerico, lead author and pharmacology graduate student Gabriela Novak and undergraduate student David Kim.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 2996 - Posted: 11.13.2002

- Bethesda, MD – In 1968, country music singer Johnny Cash recorded the fictional lament of a convict in Folsom prison. The lyrics, "I hear the train a comin'; it's rollin' 'round the bend, And I ain't seen the sunshine since I don't know when, ©" contain an acoustic anomaly, the sound of a train. Despite its insight into human nature, it's unlikely Cash knew that the sound of a train would be the catalyst for new research findings into how the brain processes auditory repetition rates. We encounter differing rates of sound each day that are important in the perception of the more complex acoustic conditions. Since repetition rate plays a fundamental role in determining how sounds are heard, it is not surprising that there have been numerous neurophysiological studies of rate in animals. Broad trends concerning the coding of rate in the auditory pathway have emerged from this work. For instance, the highest repetition rates at which neurons respond faithfully to each successive sound in a train (or each successive cycle of amplitude modulated stimuli) tends to decrease from brain stem to thalamus to cortex. While animal studies have shed light on the neural representations of repetition rate, the degree to which the animal findings are related to humans' remains uncertain because of interspecies differences, anesthesia differences, and a paucity of data in humans that can serve as a link to the animal work. In the end, direct neurophysiological data in human listeners is important to understand how repetition rate is represented in the activity patterns of the human brain.

Keyword: Hearing; Brain imaging
Link ID: 2995 - Posted: 06.24.2010

Secretin, touted as a possible cure for autism just three years ago, is not a magic bullet that relieves the symptoms of the developmental disorder, report researchers at the University of Washington and the University of Colorado Health Sciences Center. Their study, which involved the largest and most-comprehensive trials of the hormone yet conducted, is published in the November issue of Journal of the American Academy of Child Adolescent Psychiatry. "The message to parents is that there is no evidence that secretin is effective and should be given to children with autism," said Geraldine Dawson, director of the UW's Autism Center, who co-led the study. "We have yet to find a medicine that cures autism, and the results really underscore why research for the cause of autism is necessary." The study is believed to be the first to measure the effectiveness of both natural porcine secretin and a synthetic form of the hormone and a placebo. Secretin is a naturally occurring human hormone produced in the small intestine that helps control digestion and is used in diagnosing gastrointestinal problems.

Keyword: Autism; Hormones & Behavior
Link ID: 2994 - Posted: 11.13.2002

Studies find exercise triggers both beneficial and disease-associated factors, may help researcher determine optimum workout The phrase "no pain, no gain," used by coaches to prod school-age athletes, may have more meaning than they ever imagined, two UCI College of Medicine studies have found. The studies appear in the October issues of Pediatrics and Pediatric Research and suggest new ways to mark the boundary between healthy and unhealthy exercise. The research also may help physicians and others develop optimal levels of exercise that may help stave off the current epidemic of obesity in adults and children. Dr. Dan Cooper, professor of pediatrics, and his colleagues from the Center of the Study of Health Effects of Exercise in Children found that even a single, intense bout of exercise in teens and preteens raises levels of cellular chemicals that are usually associated with disease, while the same bout builds muscle mass and increases fitness. © Copyright 2002 UC Regents

Keyword: Stress; Muscles
Link ID: 2993 - Posted: 06.24.2010

Imaging of brain activity has revealed changes in cerebral blood flow (CBF) which are indicative of depression, even in patients who are in remission. Dr Mario Liotti and colleagues from the University of Texas suggest that these changes could be a marker for depression. Previous research has shown that individuals with major unipolar depression, even while in clinical remission, are vulnerable to relapse. It has been suggested that such people may be more sensitive to emotional stress, but neural correlates of such sensitivity have not been described. These researchers used positron emission tomography (PET) to investigate the changes in brain activity that occurred in remitted unipolar depression patients in whom a sad mood was induced by asking them to recollect a traumatic life event such as the loss of a relative, friend or the end of a significant relationship. Liotti et al, The American Journal of Psychiatry 2002;159:1830-1840 © HMG Worldwide 2002-1

Keyword: Depression; Brain imaging
Link ID: 2992 - Posted: 06.24.2010

BY JIM WILSON It is a question as old as Cain and Abel: Are some kids simply born bad? At long last science has an answer, in fact two answers. The short answer is yes, many criminals share a common genetic flaw. The complete answer is more complicated, and could hold the key to eradicating violent crime. The idea that crime runs in families was revived this summer when researchers at the University of Wisconsin-Madison announced they had found a direct link between genes and behavior. This story, like all others about human behavior, begins in the brain. For better or worse, every decision we make takes place in the small spaces that separate the 100 billion nerve cells in the human brain. Contrary to appearances, neurons, as brain cells are called, do not physically touch like wires. They are separated by tiny gaps known as synapses. To communicate across this void, a nerve cell releases a small amount of a class of compounds called neurotransmitters.

Keyword: Aggression; Genes & Behavior
Link ID: 2991 - Posted: 11.13.2002

By RICHARD A. FRIEDMAN, M.D. At 38, my patient Michael had reached the top of his profession but was having a lot of trouble getting along with his colleagues. They were, he revealed, afraid of his angry outbursts, which could be provoked by the faintest of criticism from them. Then in one session I got a taste of his rage myself. Feeling that I had been critical of his treatment of a subordinate at work, his usually pleasant manner abruptly changed. Glowering, he clenched his teeth and began to crush a Diet Coke can with his hands before letting lose a stream of expletives. He was having a rage attack. Michael is hardly alone with his problem. The most famous rage attack of all time was staged by Achilles, who threatened to sit out the Trojan War over a woman, but relented only after his fellow Greeks soothed his wounded vanity. Copyright The New York Times Company

Keyword: Emotions; Aggression
Link ID: 2990 - Posted: 11.13.2002

MELBOURNE,/PRNewswire/ -- A major breakthrough in autism research may lead to early detection and prevention of the condition, it was announced today at the first World Autism Congress in Melbourne, Australia. In one of the most significant finds since autism was first recognised in the 1940s, Dr Eric Courchesne of the University of California has discovered a biological development signalling the onset of autism; the brain growing too fast and two large in the first 12 months after birth. "For 60 years, scientists and doctors have been looking for an early warning signal of brain abnormality preceding autism but have found nothing. That is until now," Dr Courchesne said. Copyright © 2002 Yahoo! Inc.

Keyword: Autism
Link ID: 2989 - Posted: 06.24.2010

Scientists have found a way of making human embryonic stem cells implanted into the brains and spinal cords of rats develop into nerve cells. It could bring treatments for neurodegenerative diseases like Parkinson's and Alzheimer's a step closer to reality. Previous attempts to replace damaged nerve cells have failed, with only a few cells developing into neurons. By treating the stem cells with chemicals, the scientists succeeded in changing them into neurons. But despite this advance the researchers say there is still a long way to go before stem cells will lead to new treatments for humans. Stem cell research is being hailed by many scientists as the tool that could give rise to cures for diseases where cells are damaged in the brain and the spinal cord. (C) BBC

Keyword: Stem Cells; Regeneration
Link ID: 2988 - Posted: 11.12.2002

Adaptable eyes help crabs, shrimp endure deep sea's extreme heat David Perlman, Chronicle Science Editor In the profound darkness of the oceans' depths, where towers of lava rise on the seabed belching black smoke, scientists have found fresh evidence of evolution's power to adapt life to the most extreme environments. New studies from researchers aboard deep-diving submarines show that the eyes of crabs and shrimp can undergo the most extraordinary changes between the sunlit upper water layers and the bottom miles below where no sunlight penetrates. The eyes of these creatures may be normal near the bright surface, yet miles below, the same organs have adapted to become little more than "naked retinas" sensitive to the faintest glimmers of virtually invisible light around the undersea volcanoes. ©2002 San Francisco Chronicle.

Keyword: Vision; Evolution
Link ID: 2987 - Posted: 06.24.2010

By DONALD G. McNEIL Jr. In treating hemorrhaging cerebral aneurysms — burst blood vessels in the brain — there are two camps: the clippers and the coilers. A recent study in The Lancet, a London-based medical publication, has come out strongly in favor of coiling, a nonsurgical method far more popular in Europe than it is in the United States. A medical trial was stopped on ethical grounds when it became clear that a year after treatment 31 percent of the surgical patients were disabled or dead compared with 24 percent of the "coiled" patients. Copyright The New York Times Company

Keyword: Stroke
Link ID: 2986 - Posted: 06.24.2010

There is reassuring news for families and medical staff who care for children who spike fevers following hemispherectomy, a surgery in which half the brain is removed to relieve frequent severe seizures that medications cannot control. Researchers from the Johns Hopkins Children's Center report in the November issue of Pediatric Neurosurgery that these postoperative fevers are usually harmless. As a result, most of these children can probably be spared painful spinal taps or other invasive treatments. In one of the largest studies of its kind, Hopkins researchers reviewed the charts from 106 consecutive hemispherectomies performed at the Children's Center from January 1975 to December 2001. The review included 102 hemidecortications, a less radical form of hemispherectomy that removes the overlaying gray matter of the brain, preserving the white matter around the ventricle. Medical records were examined for information regarding immediate postoperative problems and care.

Keyword: Epilepsy; Development of the Brain
Link ID: 2985 - Posted: 11.12.2002