By SANDRA BLAKESLEE Compulsive gambling, attendance at sporting events, vulnerability to telephone scams and exuberant investing in the stock market may not seem to have much in common. But neuroscientists have uncovered a common thread. Such behaviors, they say, rely on brain circuits that evolved to help animals assess rewards important to their survival, like food and sex. Researchers have found that those same circuits are used by the human brain to assess social rewards as diverse as investment income and surprise home runs at the bottom of the ninth. And, in a finding that astonishes many people, they found that the brain systems that detect and evaluate such rewards generally operate outside of conscious awareness. In navigating the world and deciding what is rewarding, humans are closer to zombies than sentient beings much of the time. Copyright 2002 The New York Times Company

Keyword: OCD - Obsessive Compulsive Disorder; Drug Abuse
Link ID: 1557 - Posted: 02.20.2002

Stare into the intelligent eyes of a gorilla long enough, and you may start to wonder just what it is that sets us apart from our hairy cousins. Researchers long believed the answer lies in a patch of brain called the frontal cortex, which seemed to be proportionally larger in humans than in other primates. But a new comparative study of primate brains--the most comprehensive of its type to date--finds that our frontal cortex isn't any bigger than that of the great apes. The frontal cortex functions as the executive office of the brain. It plays a key role in abstract thought and language and enables us to plan and control our actions. Nearly 100 years ago, scientists reported that humans had an enlarged frontal cortex compared to other primates. Unfortunately, these studies, which were based on postmortem examinations of brains, compared humans only to the lesser apes, such as gibbons and monkeys. Our closest primate relatives, the great apes, were not included in these studies. Copyright © 2002 by the American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 1556 - Posted: 06.24.2010

– Two research teams have converged on a novel gene that appears to regulate key aspects of communication between nerve and muscle cells. Knowing the identity and function of these regulatory signals, which have remained largely mysterious until now, will allow researchers to better understand how the nervous system forges important connections during development. The two research teams – one led by Howard Hughes Medical Institute investigator Michael O' Connor and his colleagues -- reported the discovery and characterization of the gene in fruit flies in articles in the February 15, 2002, issue of Neuron. The other team, led by former HHMI investigator Corey Goodman, discovered the same gene via a different route. Both research teams identified the gene, wishful thinking (wit), by studying the larval neuromuscular junction (NMJ) in the fruit fly Drosophila. The Drosophila NMJ consists of 30 muscle fibers that are attached to 35 neurons. The well-characterized system is a prime model for exploring how muscle growth triggers the growth of its innervating motor neurons that drive muscle contraction.

Keyword: Genes & Behavior; Development of the Brain
Link ID: 1555 - Posted: 06.24.2010

Snails can teach us a great deal about how we form memories, according to a group of neuroscientists at the University of Sussex. Research by Dr Ildikó Kemenes, Professor Paul Benjamin, Professor Michael O'Shea and colleagues shows that nitric oxide plays a vital role in the formation of long-term memory in snails. This is of crucial importance because the gas has already been shown to play such a role in humans and other mammals. Ildikó Kemenes, Gyorgy Kemenes, Richard J. Andrew, Paul R. Benjamin, and Michael O'Shea: 'Critical Time-Window for NO-cGMP-Dependent Long-Term Memory Formation after One-Trial Appetitive Conditioning'. Journal of Neuroscience 22:1414-1425.

Keyword: Learning & Memory
Link ID: 1554 - Posted: 02.20.2002

A temporary alteration of serotonin activity can be obtained by acutely and reversibly lowering the blood levels of tryptophan (an amino acid precursor of the synthesis of serotonin). In several studies, acute depletion of trypotphan causes depressive symptoms in some but not all patients who have improved from at least one episode of major depression. This study investigated the relationship between depressive symptom during tryptophan depletion and the presence of a variation of the gene encoding for a protein that transports sertonin into neurons (SLC6A4). Forty three subjects who had improved from a major depressive episode and then underwent TRP depletion, were invited to participate in genetic testing. Depressive symptoms were measured with a highly standardized depression rating scale. Although during tryptopan depletion subjects experience different degrees of depressive responses, there was a clear indication that subjects whose genes predicted increased serotonin transporter activity had a lot more depression than people whose genes predicted less serotonin transporter activity. This study supports the current belief that serotonin closely regulates mood, and supports the notion that subjects with certain genetic markers may have greater vulnerability to experiencing depression. ### Citation source: Molecular Psychiatry 2002, Volume 7, number 2, pages 213-216.

Keyword: Depression; Genes & Behavior
Link ID: 1553 - Posted: 02.20.2002

New Haven, Conn. – Taking cocaine during pregnancy causes possibly permanent changes in an area of the brain that governs short term memory – leading to symptoms that are very much like attention deficit hyperactivity disorder, Yale researchers have found in two recent studies. The research team in the Neuropsychopharmacology Laboratory at Yale School of Medicine found that prenatal exposure to cocaine leads to over-stimulation of the medical prefrontal cortex of the brain in the offspring, and a dramatic impairment in learning. "Children exposed to cocaine in the womb may have a problem with excitable neurons in part of the brain that helps control attention and memory," said Bret Morrow, associate research scientist, associate clinical professor and lead author of both studies. "Potentially, this excitable prefrontal cortex may be the basis of the learning deficits in these children."

Keyword: Drug Abuse; Development of the Brain
Link ID: 1552 - Posted: 06.24.2010

Copyright © 2002 Scripps Howard News Service By SHARON SCHMICKLE, Minneapolis-St. Paul Star Tribune BOSTON ) - Couples hoping genetic research will enable them to produce little Einsteins should put that expectation on hold indefinitely, experts said at a meeting of the American Association for the Advancement of Science. Despite widespread predictions that parents would use new genetic tools to select for smarter children, scientists haven't been able to identify genes that would tell whether a child is going to be highly intelligent, said Matthew McGue, a University of Minnesota psychology professor who specializes in IQ studies. Some genes that play a role in mental retardation have been isolated, he said. But McGue and other experts in behavioral genetics said Sunday that researchers are finding the genes that influence overall intelligence and behavior to be more elusive and complex than had been expected a few years ago. Copyright © 2001 Nando Media

Keyword: Intelligence; Genes & Behavior
Link ID: 1551 - Posted: 06.24.2010

Copyright © 2002 Scripps Howard News Service By LEE BOWMAN, Scripps Howard News Service BOSTON - Scientists may be moving closer to the day when neurologists can say "brain, heal thyself." Until recently, experts were sure that new brain cells were impossible for adults to come by, that all the gray matter we get is pretty much in place well before we reach adolescence. But there's new evidence that a few regions of the brain keep churning out new cells, and new hope that the precursors of those specialized cells can be coaxed into producing other types of brain cells needed to reverse or repair damaged regions. Copyright © 2001 Nando Media

Keyword: Stem Cells; Regeneration
Link ID: 1550 - Posted: 06.24.2010

Adult mammalian brain has potential to heal itself, says U-M scientist BOSTON, Mass. - Primitive neural cells in the brains of laboratory rats respond to acute brain injuries by moving to the injured area and attempting to form new neurons, according to University of Michigan neurologist Jack M. Parent, M.D. Understanding how this self-repair mechanism works could someday help physicians reduce brain damage caused by strokes or neurodegenerative diseases. In a presentation here today at the American Association for the Advancement of Science meeting, Jack M. Parent, M.D., an assistant professor of neurology in the U-M Medical School, described results from a series of his experiments with laboratory rats. Prolonged epileptic seizures or strokes in these rats caused neural precursor cells called neuroblasts - cells midway in development between a stem cell and a fully developed neuron - to multiply and form neural chains that migrated across the brain to the site of injury. "What's fascinating is that neuroblasts responded similarly to both types of brain injury," says Parent. "There's some cue in common that activates their development and growth. We don't know what it is, but we are looking for candidate molecules - growth factors or neurotrophic factors - that stimulate the proliferation and migration of precursor cells." (c) copyright 2002 University of Michigan Health System

Keyword: Stem Cells; Regeneration
Link ID: 1549 - Posted: 02.20.2002

New Compound Blocks Fat, Drops Appetite, Boosts Calorie Burning By Daniel DeNoon WebMD Medical News -- Everyone knows the equation: eat less + exercise more = lose weight. It always works if you've got lots of will power. Now a new drug promises to help. It's called C75 and it's still a long way from human tests. Why the excitement? In a new study, C75 makes fat mice thin -- but has no effect on lean mice. Its discovery is a giant step toward helping people regain -- and maintain -- normal weight. "We are closing in on a powerful biological signal in weight control," says study leader M. Daniel Lane, PhD, professor of biological chemistry at Johns Hopkins School of Medicine, in a news release. The findings appear in today's issue of the Proceedings of the National Academy of Sciences. © 1996-2002 WebMD Corporation. All rights reserved.

Keyword: Obesity
Link ID: 1548 - Posted: 06.24.2010

Fatty acids found in many common foods may help to treat children with dyslexia and behavioural problems, say scientists. The behaviour of children with attention deficit hyperactivity disorder (ADHD) was found to improve significantly after they were given a dietary supplement containing the fatty acids. Scientists from Oxford University and London's Imperial College School of Medicine gave the supplement, Efalex, to children attending a special school in Northern Ireland. After three months, the children showed significant improvements in their behaviour and mental abilities. They were less anxious and less shy. (C) BBC

Keyword: ADHD; Dyslexia
Link ID: 1546 - Posted: 02.14.2002

Copyright © 2002 AP Online By ALEX DOMINGUEZ, Associated Press - A study of insects known as water striders has yielded what researchers claim is the first evidence of an anatomical arms race between the sexes. The researchers spotted evolutionary changes that made it easier for males to mate or for females to avoid unnecessary mating. Scientists have long theorized that such evolutionary competition between the sexes takes place in many species. But that has been difficult to prove because such changes take place over many generations. Evolutionary changes, however, are more pronounced in water striders than in birds or mammals. Copyright © 2001 Nando Media

Keyword: Sexual Behavior; Evolution
Link ID: 1544 - Posted: 06.24.2010

By Gina Barton John Masters, now 17, was knocked unconscious during a Carmel High School football camp three years ago. Although John says his headaches and dizzy spells disappeared after four days, he was sidelined for two weeks. His situation illustrates the challenge facing coaches and athletic trainers who must decide when a young athlete should return to play after a concussion. But three local high schools now have a new tool to help them make the call. With a computer program called ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing), officials at Carmel, Pike and Zionsville high schools will be able to verify whether a student-athlete's brain has fully recovered. Copyright 2001-2002 The Indianapolis Star

Keyword: Brain Injury/Concussion
Link ID: 1543 - Posted: 02.14.2002

By Steve Wiegand -- Bee Staff Writer In love? It's all in your head. Despite the avalanche of heart-shaped candy, flowers, greeting cards and balloons that bury us each Valentine's Day, (none of which is shaped like the human heart anyway), scientists say it's the organ between the ears that dictates the grand emotion. "Love is a genetically organized mechanism that is designed to make you seek a partner," said Semir Zeki, a cognitive neurologist at University College London. "People think love is out there in the air or someone has some power over them, but it's all in the brain." Zeki is part of a growing flock of scientists who are delving into how the brain functions when it comes to positive emotions. One of those emotions is love, a feeling that historically has been the province of philosophers and poets. Copyright © The Sacramento Bee

Keyword: Sexual Behavior; Brain imaging
Link ID: 1542 - Posted: 06.24.2010

by Elena M. Kouri, Ph.D. Psychiatric Times February 2002 Vol. XIX Issue 2 The question of whether a clinically significant marijuana (cannabis ) withdrawal syndrome exists remains controversial. In spite of the mounting clinical and preclinical evidence suggesting that such a syndrome exists (Beardsley et al., 1986; Budney et al., 2001; Holson et al., 1989; Huestis et al., 2001), the DSM-IV does not include marijuana withdrawal as a diagnostic category. The clinical syndrome has been characterized by restlessness, anorexia, irritability and insomnia that begin less than 24 hours after discontinuation of marijuana, peak in intensity on days 2 to 4, and last for seven to 10 days (Budney et al., 1999; Haney et al., 1999; Mendelson et al., 1984). The question of whether this syndrome is clinically significant is important, not only because marijuana is the most commonly used illicit drug in the United States (Johnston et al., 2001), but also because marijuana has been shown to produce dependence at rates comparable to other drugs of abuse (Kandel et al., 1997; Kessler et al., 1994) and because relapse rates among individuals seeking treatment for marijuana dependence are similar to those with other drugs of abuse (Budney et al., 1998; Stephens et al., 1993). Copyright 1995-2002, CME Inc.

Keyword: Drug Abuse
Link ID: 1541 - Posted: 02.13.2002

by Eric J. Nestler, M.D., Ph.D. Psychiatric Times February 2002 Vol. XIX Issue 2 Genetic factors play a significant role in addiction. Epidemiological studies have long established that alcoholism, for example, is familial, with estimates that 40% to 60% of the risk for this disorder is genetic (Kendler et al., 2000; Reich et al., 1998; Tsuang et al., 1998). Other studies have suggested similar rates of heritability for other drug addictions, such as to opiates and cocaine (Kendler et al., 2000; Kendler and Prescott, 1998; Tsuang et al., 2001). Numerous genetic linkage and association studies are now underway to identify the specific genes that comprise this risk. While investigators have identified several relatively large chromosomal regions as being possibly involved, no specific genetic polymorphism has yet been tied to addiction vulnerability with certainty. The one exception is the genetic defects found in certain East Asian populations in enzymes (e.g., alcohol and aldehyde dehydrogenases) that metabolize alcohol (Chen et al., 1999). These defects dramatically increase side effects of acute alcohol intake, thereby reducing the individual's vulnerability to alcoholism. Copyright 1995-2002, CME, Inc.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 1540 - Posted: 02.13.2002

The reason some people raid the fridge at midnight may have nothing to do with their insatiable appetite. Researchers believe that it is more likely to be down to their inability to deal with stress. The scientists, from the University of Tromso, Norway, believe 'night-eating syndrome' may also be linked to a number of other harmful psychological and physical disorders. The body's 24-hour clock is regulated by a complex pattern of hormones, which also play a role in how the body responds to stress.

Keyword: Biological Rhythms; Stress
Link ID: 1539 - Posted: 02.13.2002

Emma Young Neck manipulation by chiropractors could be a major cause of strokes in young people, say neurologists at the University of Toronto, Canada. They are now calling for the practice to be banned. John Norris and colleagues analysed 156 cases of stroke following so-called cervical artery dissection. These tears in the inside wall of a neck artery can cause blood to pool inside the artery wall, causing clots to form. The torn flap of artery can also obstruct blood flow. The clots and blockages cause strokes when regions of the brain are starved of oxygen, and brain cells start to die. Norris found that in 63 per cent of the cases, trauma caused the artery damage. In 39 per cent of cases, chiropractic neck manipulation seemed to be behind the tears, the team says. Other patients had suffered damage while turning their heads sharply playing golf or driving, for example. © Copyright Reed Business Information Ltd.

Keyword: Stroke
Link ID: 1538 - Posted: 06.24.2010

Findings published in the January 2002 edition of American Journal of Physiology -- Regulatory, Integrative, and Comparative Physiology Bethesda, MD -- New study results regarding the use of dexamethasone as a treatment for neonatal respiratory problems may add to existing concerns about the use of this steroid in premature infants. An animal study, carried out by a team of physiologists from the University of Michigan, has demonstrated the long-term effects of dexamethasone on stress response and behavior later in life. Dexamethasone (dex) is a therapy that neonatologists use because it improves the function of premature infants' lungs and consequently allows them to be removed from a ventilator more quickly. Although steroids have been used to treat ventilator-dependent premature infants who were developing chronic lung disease at one month of age, they have recently been used much earlier in an attempt to prevent chronic lung disease. Copyright © 2002, The American Physiological Society

Keyword: Hormones & Behavior; Stress
Link ID: 1537 - Posted: 06.24.2010

Study suggests mentally stimulating activities may reduce Alzheimer's risk In recent years, many of us have come to believe that doing crossword puzzles or playing cards might ward off a decline in memory or help us maintain “brainpower” as we age. Now, a new study suggests there might be some truth to the use-it-or-lose-it hypothesis. The study, by scientists at the Rush Alzheimer’s Disease Center and Rush-Presbyterian-St. Luke’s Medical Center in Chicago, IL, appearing in the February 13, 2002, Journal of the American Medical Association, found that more frequent participation in cognitively stimulating activities is associated with a reduced risk of Alzheimer’s disease (AD). The research looked at everyday activities like reading books, newspapers or magazines, engaging in crosswords or card games, and going to museums among participants in the Religious Orders Study, an ongoing examination of aging among older Catholic nuns, priests, and brothers from several groups across the U.S. On a scale measuring cognitive activity -- with higher scores indicating more frequent activity -- a one-point increase in cognitive activity corresponded with a 33 percent reduction in the risk of AD.

Keyword: Alzheimers
Link ID: 1536 - Posted: 06.24.2010