After decades of neglect by researchers more interested in know-it-all neurons, the brain cells classified as "glia" are getting some respect. They've been written off as support scaffolding for neurons or as caterers that provide nutrition. But now researchers have found that glia play an important role in setting up neural networks: They tell neurons to start talking to one another. Neurons send and receive messages through connections called synapses, points of near-contact where neurons swap chemical signals. The first indication that glia boost synaptic communication came in 1997, when a team led by neurobiologist Ben Barres of Stanford University reported that neurons grown near glial cells called astrocytes were 10 times as responsive as neurons grown alone. They just didn't know why. --LAURA HELMUTH Copyright © 2001 by the American Association for the Advancement of Science.

Keyword: Glia
Link ID: 174 - Posted: 10.20.2001

Marijuana is reputed to set the mood for love, particularly in females. Now scientists have new insights into how the drug exerts its effects--at least in rats. A study published in the 23 January Proceedings of the National Academy of Sciences shows that the drug's active compound influences acts through two chemical messengers known to have a strong influence on reproductive behavior. In rats as in people, sexual behavior requires certain hormones. If the ovaries are removed from a female rat, for example, she will no longer raise her rump when she's ready to mate. This behavior can be restored with injections of the sex hormones estrogen and progesterone--and also with shots of marijuana's active ingredient, 9-tetrahydrocannabinol (THC). Copyright © 2001 by the American Association for the Advancement of Science.

Keyword: Hormones & Behavior
Link ID: 173 - Posted: 10.20.2001

Big Babies May Grow Up Smarter Study suggests heftiness could mean a higher intellect, at least until middle age Carl T. Hall, Chronicle Science Writer Friday, January 26, 2001 Babies born a little bigger than average seem to grow up into smarter kids and young adults, scientists said yesterday. But they also found that size at birth doesn't seem to matter much by the time you reach middle age. In a large study of youngsters born in England, Scotland and Wales just after World War II, researchers found a significant link between birth weight and performance on standard cognitive tests. ©2001 San Francisco Chronicle Page A6

Keyword: Development of the Brain
Link ID: 172 - Posted: 10.20.2001

January 26, 2001- Researchers have identified a protein in the nervous system of fruit flies that is a cousin of the molecule that cocaine targets in the human brain. Their discovery offers the possibility that researchers can genetically manipulate the protein in fruit flies to gain better understanding of how cocaine alters behavior and produces addiction. ©2001 Howard Hughes Medical Institute

Keyword: Drug Abuse
Link ID: 171 - Posted: 10.20.2001

When Rats Dream, It Seems, It's After a Day at the Mazes By ERICA GOODE Elephants dream of munching sweet grass under a starry savannah sky. Dogs, paws aquiver, tails thumping faintly in slumber, chase squirrels in the park. And cats, of course, dream of mice. Or so humans, prone to anthropomorphic conjecture about the four- legged world, have long suspected. Yet what animals dream about - or indeed, whether they dream at all - has remained resistant to scientific scrutiny, if only because animals cannot describe their closed-eye experiences in words. Copyright 2001 The New York Times Company

Keyword: Sleep
Link ID: 170 - Posted: 11.06.2001

The Laboratory of Neuro Imaging was originally established to study cerebral metabolism with the goal of understanding the relationship between brain structure and function using image data. Work progressed into three-dimensional reconstruction and visualization. This enabled the study of functional anatomy in the same geometric configuration as that found in the living animal. As these reconstructions became more sophisticated, their application to computational atlases became possible. Human brain structure and function are so complex that powerful computational tools are required to analyze brain data. Given the fact that there is neither a single representative brain nor a simple method to construct an 'average' anatomy or represent the complex variations around it, the construction of brain atlases became the focus of intense research. Brain atlases are based on detailed representations of anatomy in a standardized 3D coordinate system. The Laboratory addressed the prob! lem of comparing data across individuals as well as across modalities and increased work in humans began. Work focused on statistical manipulation of the geometry that made up the anatomic and functional data sets as well as sophisticated visualizations permitting the communication of the results.

Keyword: Miscellaneous
Link ID: 168 - Posted: 10.20.2001

Jet Lag of the Liver Adjusting meal times may help travelers avoid the stomach upset sometimes associated with jet lag, suggests new research on circadian rhythms. The bane of globe-trotters, jet lag occurs when a person's sleep schedule is at odds with local time. Sunlight helps adjust the body clock, and now there may be another way to help get the system acquainted to a new time zone. In today's Science, researchers report that the timing of meals can reset a biological clock in the liver, which might help it rev up enzyme production at the right time for digestion. The finding may one day help doctors optimize the timing of treatments for liver diseases. The body is full of clocks. These circadian rhythms--such as waxing and waning levels of the expression of certain genes--tick in organs from the lungs to the liver. Normally, these rhythms are in step with a master clock in the brain that is controlled by the cycle of daylight and darkness. However, it's not known if the brain synchronizes the other clocks directly (through the timed release of hormones, for example) or if external stimuli play a role in setting them. --GREG MILLER Copyright © 2001 by the American Association for the Advancement of Science.

Keyword:
Link ID: 167 - Posted: 10.20.2001

Protein May Tie Obesity to Diabetes Nathan Seppa The high incidence of obesity among people with type II diabetes suggests a connection between the two conditions. Scientists have sought a link by studying insulin resistance, the trademark symptom of type II, or adult-onset, diabetes. But they still don't know why cells in people with insulin resistance ignore insulin's signals to process blood glucose for use by muscles and other tissues. Researchers working with mice have now identified a hormone, called resistin, that is secreted by fat cells and appears to play a direct role in type II diabetes. Healthy mice given doses of extra resistin for 2 days develop insulin resistance, researchers at the University of Pennsylvania in Philadelphia report in the Jan. 18 Nature. From Science News, Vol. 159, No. 3, Jan. 20, 2001, p. 36. Copyright © 2001 Science Service. All rights reserved.

Keyword: Obesity
Link ID: 166 - Posted: 10.20.2001

How Your Brain Knows Your Face Breakthrough tests show self-recognition is an ability of the right lobe Keay Davidson, Chronicle Science Writer Thursday, January 18, 2001 Somewhere inside the brain, obscured by thickets of neural circuitry and throbbing blood vessels, is the "self" -- that murky whatever-it-is that makes you feel like a conscious, self-aware human being. For centuries, scholars have debated what the self is. Is it a nonmaterial entity -- a little ghost, as it were -- that can't possibly be explained in terms of biology, physics or chemistry? Or is it a purely material thing, one that generates a person's sense of selfhood as a cathode-ray tube generates TV images? Now -- with a little help from Marilyn Monroe, Princess Diana, Bill Clinton and Albert Einstein -- scientists are beginning to analyze the neurological machinery that enables one to look in a mirror and say: "That's me." ©2001 San Francisco Chronicle Page A2

Keyword: Attention
Link ID: 163 - Posted: 10.20.2001

Link found between diabetes and obesity DAVID ADAM More than 80% of diabetics are also obese, but a link between the two conditions has proved difficult to find. Now, in a series of experiments with mice, Mitchell Lazar and his colleagues at the University of Pennsylvania School of Medicine, Philadelphia, show that a protein called resistin, which is produced by fat cells, plays a role in diabetes. The team suggests that, if the action of human resistin is similar to mouse resistin, new drugs targeting the hormone could bring relief from diabetes, which can lead to heart disease, stroke, kidney failure and nerve damage. Diabetic mice with both diet-induced and genetic obesity have higher resistin levels. The researchers also show that an antidiabetic drug reduces resistin, and that administering an antiresistin antibody improves blood-sugar control and insulin action in mice on a high-fat diet. .... 1.Steppan, C. M. et al. The hormone resistin links obesity to diabetes. Nature 409, 307–312 (2001). © Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Obesity
Link ID: 162 - Posted: 06.24.2010

Boom and bust DAVID ADAM Gravel in a man's throat means hair on his chest, or so women believe. Ladies rate unseen men with deeper voices as more attractive, older, heavier and hairier, new research reveals. But arranging a blind date over the telephone could be surprising - baritone blokes are no more likely to be muscle-bound than are their soprano-sounding friends. Sarah Collins, a behavioural biologist at the Institute of Evolutionary and Ecological Sciences in Leiden, the Netherlands, recorded Dutch men's voices and played them to Dutch women, who then tried to predict what the speakers looked like. 1.Collins, S. Men's voices and women's choices. Animal Behaviour 60, 773–780 (2001). © Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2001 Reg. No. 785998 England.

Keyword: Sexual Behavior
Link ID: 161 - Posted: 06.24.2010

New Haven, Conn. -- Continued use of anti-depressants leads to new cell growth in an area of the brain known to suffer cell death and atrophy as a result of depression and stress, a study by Yale researchers shows. Depression affects an estimated 12 percent to 17 percent of the population at some point during their lifetime. Anti-depressants are commonly prescribed for depression and other affective disorders, but the drugs' therapeutic effects on the molecular and cellular level are not clearly understood.

Keyword: Depression
Link ID: 160 - Posted: 10.20.2001

Birds Follow the Sun Following the sun imperfectly turns out to be the perfect solution for navigation if you're a bird in the Arctic, researchers have found. By using the sun to orient themselves, tundra-breeding shorebirds end up approximating the "great circle routes" used by airplanes and ships--routes that minimize the distance between two points on the surface of a sphere. Birds can travel thousands of kilometers and arrive at breeding and wintering grounds with pinpoint precision. Fascinated, biologists have investigated this ability for decades. They've learned that birds take their bearings from such things as stars, the sun, landmarks, and Earth's magnetic field. But existing ideas didn't explain why some birds in the Arctic fly east before heading south. So ornithologist Thomas Alerstam of Lund University in Sweden and colleagues used the radar on a Canadian icebreaker in the Northwest Passage to measure the direction of migrating birds flying past. .... --JAY WITHGOTT Copyright © 2001 by the American Association for the Advancement of Science.

Keyword: Miscellaneous
Link ID: 159 - Posted: 10.20.2001

Academic impacts of vegetarian childhoods By Janet Raloff Teens are always looking for creative excuses for late homework, low test scores, and waning attention in class. Any who stumbled onto a copy of the September AMERICAN JOURNAL OF CLINICAL NUTRITION may have uncovered the basis for a particularly novel rationalization: "My parents made me a vegetarian." Plants do not make vitamin B-12, also known as cobalamin. Diets that eschew all animal products can therefore lead to B-12 deficiencies. Because the vitamin plays a key role in some brain functions, toddlers raised from weaning on strictly plant-based foods can experience delays in the acquisition of certain motor skills. In a few instances, infants in strictly vegetarian families have shown severe anemia, dramatic growth retardation, irritability-and in at least one case, went into a coma. References: Louwman, M.W.J., et al. 2000. Signs of impaired cognitive function in adolescents with marginal B-12 status. American Journal of Clinical Nutrition 72(September):762. Watanabe, F., et al. 1998. Effects of microwave heating on the loss of vitamin B12 in foods. Journal of Agricultural and Food Chemistry 46(January):206. Copyright © 2001 Science Service. All rights reserved.

Keyword: Development of the Brain
Link ID: 158 - Posted: 10.20.2001

MIT researchers find individual brain cells 'tuned' to entire categories of information Monkeys learn to see differences between cats and dogs JANUARY 11, 2001 Contact information CAMBRIDGE, Mass. -- Researchers at the Massachusetts Institute of Technology found that individual neurons in monkeys' brains can become tuned to the concept of "cat" and others to the concept of "dog. The study suggests that people, too, have individual neurons sensitive to categories of our most familiar things. This is the first time, the MIT researchers report in the Jan. 12 issue of Science, that individual brain cells have been linked with one of the brain's most important cognitive functions: the ability to instantly categorize what we see.

Keyword: Neurotoxins
Link ID: 157 - Posted: 10.20.2001

Herring aid DAVID ADAM Fish living in the murky rivers of West Africa have evolved their own hearing-aids. A tiny gas-filled bubble inside the ear of the mormyrid electric fish vibrates as mating calls or alarm signals pass through the water. The fish hears the sounds because the bubble brushes against sensory hairs. Deflating the bubble renders the fish deaf, Lindsay Fletcher and John Crawford at the University of Pennsylvania, Philadelphia, now report. Biologists have suspected that the bubbles are crucial to mormyrid hearing since the 1930s, but advances in surgery have only now allowed the idea to be tested. 1.Fletcher, L. B. & Crawford, J. D. Acoustic detection by sound-producing fishes (Mormyridae): the role of gas-filled tympanic bladders. Journal of Experimental Biology 204, 175–183 (2001). 2.Yan, H. Y. & Curtsinger, W. S. The otic gasbladder as an ancillary auditory structure in a mormyrid fish. Journal of Comparative Physiology A 186, 595–602 (2000). .© Macmillan Magazines Ltd 2001 - NATURE NEWS SERVICE Nature © Macmillan Publishers Ltd 2000 Reg. No. 785998 England.

Keyword: Animal Communication
Link ID: 154 - Posted: 06.24.2010

Eavesdropping on Secrets of Elephant Society By ANDREW C. REVKIN Katharine Payne is one of science's consummate listeners. Starting first with whales, and then moving ashore to study elephants 16 years ago, she has built a career divining the significance of sounds emitted by two of the world's largest, and most mysterious, mammals. Andrea Turkalo is one of science's consummate watchers. A former biology teacher in the South Bronx, she has spent a decade perched on a rough- hewn platform in an opening in the rain forests of the Central African Republic, intently observing the interactions of hundreds of forest elephants that briefly leave the dense jungle to partake of the minerals and water in mudholes there. It is estimated that perhaps half of Africa's remaining elephants are of the forest-dwelling subspecies, and thus live largely out of sight and are barely understood. Copyright 2001 The New York Times Company

Keyword: Animal Communication
Link ID: 153 - Posted: 10.20.2001

GenSAT, others to house rapidly expanding genetic data
By Jean McCann
Researchers maintain and constantly add to numerous gene databases as science progresses in its effort to map the human body. The recent announcement of a major new database initiative, however, may, as one researcher noted, "change the culture of neuroscience." Thanks to financial support from the National Institute of Neurological Disorders and Stroke, explained Gabrielle LeBlanc of NINDS during the recent Society for Neuroscience annual meeting in New Orleans, neuroscientists will be able to access images of gene expression from the brain in one database instead of gathering data from many disparate sources. The GenSAT project, named after NASA's LANDSAT, which shows population densities or other features as captured by satellites, will show regions of density of highly activated gene expression as seen through fluoroscopic microscopes. "We expect this to be a tremendous resource for the community, because now they won't have to do this piecemeal on a lab-by-lab basis, but everyone will have a common pool of knowledge that they can look at and analyze how genes are expressed," said LeBlanc, who demonstrated a prototype of the database at the neuroscience meeting. She also described how the database could interact with microarray and mutational analysis for the better understanding of gene function. Jean McCann (jmmednews@aol.com) is a science writer in Cleveland Heights, Ohio. The Scientist 15[1]:8, Jan. 8, 2001 © Copyright 2001, The Scientist, Inc. All rights reserved.

Keyword: Genes & Behavior
Link ID: 151 - Posted: 10.20.2001

Music Through the Years and Ears Scientists say a taste for melody crosses lines of time and species David L. Chandler, Boston Globe Friday, January 5, 2001 It has long been a cliche that music is universal, but now science is proving just how deeply true the old saying really is. While scientists can't do much better than the rest of us in defining exactly what music is -- although they know it when they hear it -- they have shown that human appreciation of music is remarkably ancient, begins astonishingly early in life, and to a surprising extent may be shared by whales, birds and even rats. ©2001 San Francisco Chronicle Page A8

Keyword: Hearing
Link ID: 148 - Posted: 10.20.2001

DURHAM, N.C. - In experiments using cell cultures and gene-altered mice, researchers have found that switching on just two genes can induce considerable regeneration of damaged nerve fibers in the spinal cord. Their finding suggests that genetic therapy or drugs that activate perhaps only a handful of genes might be enough to induce regeneration of spinal cords in humans with spinal cord injury or other central nervous system damage. In addition, the scientists said their in vitro method of testing the effects of such treatments on cultured nerve cells should speed research on such therapies.

Keyword: Regeneration
Link ID: 147 - Posted: 10.20.2001