Researchers Fear Navy's Sonar May Harm Whales By RACHEL X. WEISSMAN Last spring Kenneth Balcomb, a marine mammalogist, woke to find an unsettling situation outside his Abaco Island home in the Bahamas: a 16-foot Cuvier's beaked whale weighing some two tons stranded in knee-deep water. With the help of several volunteers, Mr. Balcomb, who heads the Center for Whale Research in Friday Harbor, Wash., tried to push the animal out to sea. After the fifth attempt, the disoriented whale stopped turning toward shore and continued into the open ocean. But that was only the start. Copyright 2001 The New York Times Company

Keyword: Animal Communication
Link ID: 239 - Posted: 10.20.2001

April 6, 2001- By studying mice whose brains contain a composite of neurons that produce normal and longer-than-normal circadian rhythms, researchers are beginning to understand how neurons synchronize their oscillatory behavior to control the body's 24-hour, internal clock. The experiments represent the beginning of a new research direction, say the scientists, that progresses beyond discovering the genes that produce the internal clock machinery to exploring how brain cells interact to produce coherent circadian rhythms. ©2001 Howard Hughes Medical Institute

Keyword: Biological Rhythms
Link ID: 238 - Posted: 11.06.2001

Kids' got rhythm JOHN WHITFIELD To a three-year-old, the William Tell Overture and Chopin's Funeral March probably sound equally jolly, a new study suggests. But by the age of about six, children's ability to distinguish happy from sad music is fully formed. Five-year-olds, on the other hand, associate slow tempo with misery, but are not tuned in to the emotional resonance of major and minor keys. Simone Dalla Bella, of the University of Montreal, and colleagues found that children of five and above correctly matched the structure of synthesized snippets of classical music [click to see and hear details ] to mood more than four-fifths of the time1. 1.Dalla Bella, S., Peretz, I., Rousseau, L. & Gosselin, N. A developmental study of the affective value of tempo and mode in music. Cognition (in the press). Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Hearing
Link ID: 237 - Posted: 10.20.2001

Patients with lesions of amygdala shown no enhanced awareness of the presentation of emotionally evocative words
Humans are not passive perceivers, giving equal access for entry into consciousness to all stimuli; we can ignore some events, words, and stimuli, but not others. For instance, our perceptions are influenced by the emotional significance of an impinging stimulus. Determining how the brain "decides" to attend to some stimuli and ignore others is emerging as a critical issue in neuroscience.

Keyword: Emotions
Link ID: 236 - Posted: 10.20.2001

how brain responds to fears that are imagined and anticipated, but never experienced NYU neuroscientist Elizabeth A. Phelps and colleagues at Yale University find that the left amygdala responds to cognitive representations of fear Although people learn about potentially dangerous events through hard experience (a given dog is dangerous because it once bit you), often we learn about such events through communication (a given dog is dangerous because you heard it bit somebody else.) In understanding the neural systems of fear learning, most researchers have focused on the former type of learning, which is called fear conditioning. However, little is known about the neural system underlying fear-learning through communication, in the absence of aversive experience. Using fear conditioning, the neural systems of fear learning and expression have been eloquently mapped with both human and animal research.

Keyword: Emotions
Link ID: 235 - Posted: 10.20.2001

Nearly a decade ago, researchers determined that the brain contains a molecule that mimics the active ingredient in marijuana, but its location and role in the brain were unclear. Now, UCSF researchers have discovered that the molecule acts, at least in part, in a region of the brain that plays a key role in learning and memory. The study, reported in the March 29 issue of Nature, suggests, the researchers say, that the molecule, known as a cannabinoid, plays a role in particular cognitive functions within a structure known as the hippocampus. Paradoxically, marijuana disrupts cognitive function and the likely explanation, the researchers say, is that marijuana disrupts the very cognitive system the cannabinoid normally supports. Copyright 2001 Regents of the University of California. All Rights Reserved.

Keyword: Drug Abuse
Link ID: 234 - Posted: 10.20.2001

New Haven, Conn. -- Researchers at Yale and Rockefeller Universities have found that an enzyme called Cdk5 regulates the action of dopamine, a chemical messenger associated with cocaine's "rush" and with addiction to cocaine and other drugs. According to Jingshan Chen, assistant professor of psychiatry at Yale, the Cdk5-related process leads to changes in brain cells that are thought to play a key role in cocaine addiction.

Keyword: Drug Abuse
Link ID: 233 - Posted: 10.20.2001

Smell reflects shape HELEN PEARSON Rats' noses are so finely tuned that they can distinguish mirror-image molecules that humans can't tell apart, new research reveals1. Many molecules come in two forms, called enantiomers, which are mirror images of each other but otherwise identical, like left- and right-handed gloves. Certain enantiomers have entirely different odours: the molecule carvone smells like caraway to us in one formation and like spearmint in the other. Others, like butanol, smell exactly the same - like alcohol fumes. 1.Rubin, B.D. & Katz, L.C. Spatial coding of enantiomers in the rat olfactory bulb. Nature Neuroscience 4, 355­356 (2001). © Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 232 - Posted: 10.20.2001

Mole nose its own mind HELEN PEARSON "It's a biological novelty," says Ken Catania of his favourite organ, the incredibly touch-sensitive snout of the star-nosed mole. Now research from his lab shows that nerves from the nose fight for extra space in the brain1. The findings could help us to understand how our brains allocate space to the senses. Twenty-two fleshy little fingers protruding from around the star-nosed mole's nostrils probe its swampy underground world. "It probably has the best sense of touch of any mammal," says Catania, of Vanderbilt University in Tennessee. This due to the large numbers of nerve fibres packed into the animal's nose. 1.Catania, K.C. Early development of a somatosensory fovea: a head start in the cortical space race? Nature Neuroscience 4, 353­354 (2001). © Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Pain & Touch
Link ID: 231 - Posted: 10.20.2001

Evolving Before Our Eyes Songbirds and salamanders bolster Darwin's theory that change in habitat can create 2 species from one David Perlman, Chronicle Science Editor Monday, March 26, 2001 When Charles Darwin pondered the wonderfully diverse beaks and bodies and lifestyles of the finches on the Galapagos Islands, he wrote these classic words: "Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds one species had been taken and modified for different ends." It was an idea that was to strike him again and again because, in the 13 different species of Galapagos finches, the young naturalist saw the living results of creatures adapting to pressures imposed by varying environments. ©2001 San Francisco Chronicle Page A - 6

Keyword: Evolution
Link ID: 230 - Posted: 10.20.2001

Men with Chronic Schizophrenia Lose Brain Volume Faster New Haven, Conn. -- Men with chronic schizophrenia lose brain volume at a faster rate than the normal aging changes seen in men without the mental illness, a study by a researcher at Yale shows. "We found that there was evidence of progressive decline in brain volume in men with chronic schizophrenia, and it tended to occur in the frontal and temporal lobes," said Daniel Mathalon, M.D., assistant professor of psychiatry at Yale School of Medicine. "These are the two regions already implicated in the pathophysiology of schizophrenia."

Keyword: Schizophrenia
Link ID: 229 - Posted: 10.20.2001

Device offers relief from Parkinson's
Carl T. Hall, Chronicle Science Writer, Wednesday, March 21, 2001
A little-heralded device that has achieved remarkable results controlling symptoms of Parkinson's disease is gaining new attention even as hopes for a cure seem to dim. The device is a "deep brain stimulator" that makes use of electrical pulses, acting as a sort of pacemaker for the brain. Although it may be too early to assess its full potential, the device appears capable of restoring a measure of normal movement in many cases. 2001 San Francisco Chronicle Page A - 3

Keyword: Parkinsons
Link ID: 228 - Posted: 10.20.2001

Memories May Need Fresh Neurons Neurons are the stuff memories are made of, and new memories may require new stuff, according to a report just released. If researchers treat rats with a drug that kills budding neurons, the rats develop memory problems. The finding suggests that a steady, lifelong supply of fresh neurons may be important for maintaining the brain circuits that encode memories. For many years, neuroscientists thought that the brains of adult mammals don't grow additional neurons. Then studies showed that neurons pop up throughout life in some regions of the brain, including the hippocampus, an area important for building new memories. However, whether these new neurons actually do anything important has remained a mystery. --GREG MILLER Copyright © 2001 by the American Association for the Advancement of Science.

Keyword: Learning & Memory
Link ID: 227 - Posted: 10.20.2001

Dyslexia Harder on English Speakers, Researchers Find Jamie Talan, Newsday Friday, March 16, 2001 Studying diverse groups from three countries, researchers have discovered that dyslexic people, regardless of their native languages, have the same brain abnormality, even though some countries have much lower rates of dyslexia than English-speaking countries. According to the study, appearing today in the journal Science, there are twice as many identified dyslexics in English-speaking cultures as in countries with less complex languages. Languages with more complex writing and reading systems, such as English and French, are more difficult for people with or without dyslexia. ©2001 San Francisco Chronicle Page D - 3

Keyword: Dyslexia
Link ID: 226 - Posted: 10.20.2001

A Night to Remember Neuroscientists probe possible connections between sleep and memory consolidation By Douglas Steinberg Throughout history, humans have felt a compulsion to explain their dreams. In the Bible and Shakespeare, dreams were omens. Joseph interpreted Pharaoh's dream to predict seven years of plenty and seven of famine. Calpurnia's nightmare in Julius Caesar foretold the assassination of her husband. According to modern science, dreams reflect operations of the mind or brain. Sigmund Freud called dreams the "royal road" to the subconscious, and experimental psychologists hypothesized that dreams help establish long-term memories. A generation ago, the dreaming/memory theory bogged down in conflicting results and questionable methods. But neuroscientists have recently revived it by applying sophisticated brain-recording techniques, making finer distinctions between various forms of memory, and scrutinizing organisms besides humans and rodents. The experiments are difficult to conduct and analyze, so these studies are far from nailing down the role of dreaming. © Copyright 2001, The Scientist, Inc. All rights reserved.

Keyword: Learning & Memory
Link ID: 225 - Posted: 10.20.2001

HELEN PEARSON We can block out some unwanted memories - if we try really hard not to think about them, a new study suggests. The research, from the University of Oregon in Eugene, and published in this week's Nature1, should help us to understand the memory loss people suffer after traumatic events. Sigmund Freud, the founder of psychoanalysis, claimed that we can deliberately forget or 'repress' unpleasant memories; thus, abused children may forget harrowing past events. A century on, whether or not we can really choose to lose memories remains a controversial question. Traumatic memories are wrapped up in human emotion, which is difficult to study in the lab. 1.Anderson, M. C. & Green, C. Suppressing unwanted memories by executive control. Nature 410, 366­369 (2001) 2.Shors, T. J., Miesegaes, G., Beylin, A., Zhao, M., Rydel, T. & Gould, E. Neurogenesis in the adult is involved in the formation of trace memories. Nature 410, 372­376 (2001) © Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Stress; Neurogenesis
Link ID: 224 - Posted: 10.20.2001

Shock tactics for new neurons HELEN PEARSON Like jump-starting a car, one way to regrow nerves after injury may be to shock them. A study released this month shows that electric currents can spark growth in embryonic nerve cells, raising hopes that the same might be true of adult neurons1. Nerve cells in the developing embryo have to find their way over long distances through the spinal cord and brain. A growing nerve tip, or 'growth cone', encounters patches of guidance molecules. These tell it which direction to take. 1.Ming, G., Henley, J., Tessier-Lavigne, M., Song, H. & Poo, M. Electrical activity modulates growth cone guidance by diffusible factors. Neuron 29, 441-452 (2001). Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Development of the Brain
Link ID: 223 - Posted: 10.20.2001

Sex drives birds apart CORIE LOK New evidence from more than 1,000 of the world's bird species backs up Charles Darwin's theory that male birds tend to be bigger, brighter and more colourful than females because of their differing approaches to sex1. Peter Dunn of the University of Wisconsin-Milwaukee and his colleagues collected bird size and plumage data from the scientific literature and from 12 museums around the world. They found that more promiscuous species display greater sexual differences in body mass, feather colour and patterns, and wing and tail length than monogamous species. 1.Dunn, P. O., Whittingham, L. A. & Pitcher, T. E. Mating systems, sperm competition and the evolution of sexual dimorphism in birds. Evolution 55, 161­175 (2001). © Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Evolution
Link ID: 222 - Posted: 10.20.2001

Scientists Test Hallucinogens for Mental Ills By SANDRA BLAKESLEE Hallucinogenic drugs like LSD and peyote - derided as toys of the hippie generation - are increasingly drawing the interest of neurologists and psychiatrists who want to test the idea that they may be valuable tools in treating a range of mental disorders. Although there are anecdotal reports that psychedelic drugs can help some people with mental illness, the idea has never been substantiated by mainstream psychiatry and remains highly controversial - some would say outlandish. And even the researchers involved in the new work are not suggesting that people start medicating themselves with hallucinogens. Copyright 2001 The New York Times Company

Keyword: Drug Abuse
Link ID: 221 - Posted: 10.20.2001

Researchers Discover Mechanism of Natural Recovery from Spinal Cord Injury Findings Have Potential for New Therapies Researchers have discovered that rats with spinal cord injuries show some motor-function recovery several weeks after injury based on spontaneous re-growth of spared nerves. This finding has potential to further advance recovery after spinal cord injury. The research was conducted at the University of California, San Diego (UCSD) School of Medicine and the Veterans Affairs Medical Center, San Diego, and is described in the March 13, 2001 issue of the Proceedings of the National Academy of Sciences.

Keyword: Regeneration
Link ID: 220 - Posted: 10.20.2001