Rats can emulate three key signs of addiction in humans, new research has shown. The findings provide the first-ever animal model showing a transition from drug usage to drug addiction, which could in future enable the development of new therapies. Animals have been shown to have a preference for drugs since early studies in the 1960s. But it was not clear whether the animals simply derived pleasure from the substances or whether they were actually addicted to them. So Pier Vincenzo Piazza and colleagues at the Bordeaux Institute for Neurosciences, France, set up an experiment in which freely moving rats could obtain traces of cocaine by poking their noses into a hole. After a three-month period the rats were not only extremely reluctant to cut down on their drug use, they had an unusually high desire for the cocaine and would seek it even when it was accompanied with an electric shock to the foot. “This tells us addiction is not a social phenomenon, but a brain disease,” Piazza told New Scientist. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 5989 - Posted: 06.24.2010

Two factors help children escape problems People diagnosed with either fetal alcohol syndrome (FAS) or fetal alcohol effect (FAE) are more likely to escape social and relationship problems if they are diagnosed early in life and raised in a stable and nurturing environment, according to research by University of Washington Professor Ann Streissguth. In an article published in the Aug. 12 edition of the Journal of Developmental and Behavioral Pediatrics, Streissguth, professor of psychiatry and behavioral sciences in the UW School of Medicine, said that her study of 415 subjects showed that of all the factors that might positively or negatively affect a child with FAS or FAE, these two factors are most important in helping them escape negative experiences. Those negative experiences can include confinement for criminal violations and other reasons, trouble with the law, inappropriate sexual behavior, alcohol or drug problems and disrupted education. "This is the first study to show that despite the prenatal brain damage caused by their mothers' consumption of alcohol during pregnancy, these children can grow up to have relatively more successful lives," Streissguth said. "Our interviews with the caregivers of our study subjects, who ranged in age from 6 to 51 years, showed that the odds of escaping these adverse life experiences are improved two-to-four-fold by being diagnosed with FAS or FAE at an early age and by being raised in a good stable environment

Keyword: Drug Abuse; Development of the Brain
Link ID: 5988 - Posted: 08.13.2004

Arlington, Va.--An international team of scientists has traced the evolution of hearing in modern cetaceans (whales, dolphins and porpoises). "This study of the early evolution of whales demonstrates the changes that took place in whales' outer and middle ears, required for the transition from a land-based to a marine-based existence," said Rich Lane, director of the National Science Foundation (NSF)'s geology and paleontology program, which funded the research. The findings are published in the Aug. 12 issue of the journal Nature. The ear is the most important sense organ for modern toothed whales, say scientists, because these whales locate their prey using echolocation. Directional hearing is critical: A blind such whale could find food without much trouble; a deaf one would starve. The study documents how hearing in these whales evolved. The research is based on cetacean fossils representing four groups of early whales. The earliest cetaceans, pakicetids (those that swam in ancient seas 50 million years ago), used the same sound transmission system as did land mammals, and so had poor underwater hearing. More recent cetaceans, remingtonocetids and protocetids (those that lived 43-46 million years ago), retained the land-mammal system, but also developed a new sound transmission system.

Keyword: Hearing; Evolution
Link ID: 5987 - Posted: 08.12.2004

Helen Pilcher Procrastinating primates can be turned into workaholics, thanks to gene therapy. The discovery, which sheds light on the workings of the brain's reward centre, may further our understanding of mood disorders, such as depression and obsessive-compulsive disorder. Like many humans, monkeys tend to slack off when their goal is distant, then work harder as a deadline looms. But when a key gene is turned off, the primates work hard from the word go, researchers report in PNAS Online1. "The gene knockdown triggered a remarkable transformation in the simian work ethic," says Barry Richmond of the National Institute of Mental Health in Bethesda, Maryland, who studied the animals. Richmond's team trained four monkeys to release a lever when a spot on a computer screen turned from red to green. The animals had to complete several trials correctly before they received a reward. To give them an idea of how many trials were left, a grey bar on the screen became progressively brighter as the task progressed. ©2004 Nature Publishing Group

Keyword: Drug Abuse; Genes & Behavior
Link ID: 5986 - Posted: 06.24.2010

Boys exposed to persistent levels of cocaine in the womb are more likely to have behavioral problems like hyperactivity in their early school years, new research suggests. But girls who had prenatal exposure to similar amounts of cocaine were not more likely to suffer from the same problems, Virginia Delaney-Black, M.D., of Children's Hospital of Michigan and colleagues found. The study results are published in the Journal of Developmental and Behavioral Pediatrics. While no specific cause of the gender-specific findings was identified, the researchers note that the study confirms animal studies that also suggest gender plays a role in the effects of cocaine exposure. Delaney-Black and colleagues say human studies have been "inconsistent" on the question of whether prenatal cocaine exposure has gender-specific effects on children's development. The study looked at 473 children in the Detroit area ages 6 to 7 whose mothers had received prenatal care and drug testing. About 200 of the children in the study were prenatally exposed to cocaine. Children were considered "persistently" exposed if they or their mothers tested positive for traces of cocaine in their urine at the time of birth. To determine whether these children had a higher likelihood of behavioral and other cognitive problems, Delaney-Black and colleagues collected information on the children's behavior from their teachers.

Keyword: Drug Abuse; Development of the Brain
Link ID: 5985 - Posted: 08.12.2004

Researchers at the NIH's National Institute of Mental Health (NIMH) have identified a relationship between a small section of one gene, the brain chemical messenger glutamate, and a collection of traits known to be associated with schizophrenia. The finding confirms the gene responsible for management of glutamate is a promising candidate in determining risk for schizophrenia. The study, conducted by Michael Egan, M.D., Daniel Weinberger, M.D., and colleagues, is published in the August 9, 2004, of the Proceedings of the National Academy of Sciences. Glutamate is a key neurotransmitter long thought to play a role in schizophrenia. The gene identified in this study makes the glutamate receptor (GMR3) which is responsible for regulating glutamate in synapses—spaces in between brain cells"—"where chemicals like glutamate transfer information from cell to cell. The amount of glutamate remaining in the synapse may have a downstream impact on cognition. "Because of the small effects of individual genes in complex genetic disorders like schizophrenia, it is difficult to make significant associations with any one particular marker. However, this study brings us closer to unlocking the genetic clues that increase the risk for schizophrenia," said NIMH Director Thomas R. Insel, M.D. Researchers know that schizophrenia affects several regions in the front part of the brain that are involved in higher order thinking and decision-making and neurotransmitter systems like glutamate. Many of the genes already identified as likely candidates for the disorder have been thought to affect the glutamate system. The study implicates the GMR3 gene as well.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 5984 - Posted: 06.24.2010

Drugs Linked to More Suicides Among Children, Unpublished Analysis Says By Shankar Vedantam, Washington Post Staff Writer Six months after the Food and Drug Administration withheld an internal finding that antidepressant medications were associated with an increased risk of suicide among children, a second staff analysis has arrived at the same conclusion. The agency has not publicly disclosed either report, despite growing pressure from critics and Congress. Agency officials say they do not plan to discuss the data until a scheduled meeting in September, which would come nine months after British authorities warned physicians not to prescribe Paxil, Zoloft, Celexa and similar drugs to depressed children, and more than a year after the first concerns emerged. The new analysis has renewed the complaints of critics that the FDA is moving too slowly to address the concerns about suicide. One leading expert who reviewed the two internal analyses said they had changed his thinking about the risks. "I didn't have access to the proprietary data" reflected in the FDA analyses, said Steven Hyman, former director of the National Institute of Mental Health, who initially thought British regulators had overreacted. Hyman reviewed the analyses at the request of The Washington Post. © 2004 The Washington Post Company

Keyword: Depression; Development of the Brain
Link ID: 5983 - Posted: 06.24.2010

Anabolic steroids, abused by athletes to increase performance, weaken the body's natural defence against infections and cancer, tests show. Australian scientists found that, even at doses 50 times lower than those commonly used by abusers, the drugs dampened the immune system. Volunteers testing the drugs for Southern Cross University also reported changes in their personality. The reduced empathy they felt may explain the condition 'roid rage'. This is when people taking steroids become overly aggressive. For six weeks, a group of 24 athletes from different countries agreed to take anabolic steroids for the purpose of the investigation. At the beginning of the study the volunteers took part in a series of athletic events to measure their personal as well as their competitive performances, and their strength, speed and endurance. They were divided into two groups, one group receiving injections of the anabolic steroid testosterone enanthate (3.5 milligrams per kilogram of bodyweight per week) and the other receiving harmless dummy injections. Neither group nor the scientists overseeing the experiment, commissioned by New Scientist and Channel 4, knew who was given what. (C)BBC

Keyword: Aggression; Hormones & Behavior
Link ID: 5982 - Posted: 08.11.2004

Genes could explain why women are more prone to stress-related anxiety and mood disorders. US researchers have pinpointed a variation in a gene which controls regulation of a key brain chemical linked to mood. Their work, on monkeys, suggests people with this variant may be more likely to react badly to negative experiences. The US National Institute on Alcohol Abuse study appears in Proceedings of the National Academy of Sciences. The researchers focused on a particular variant of the gene, known as the s allele. People with this variant produce less of a protein that is involved in regulating levels of a chemical called serotonin in the brain. Previous research has suggested that people were more likely to become depressed after going through a bad experience if they carried this gene variant. For the latest study, the researchers measured stress hormone levels in 190 infant rhesus macaque monkeys when the animals were the equivalent of about nine to 24 months old in human development terms. Some of the measurements were made after the animals had been socially separated for 30 minutes - a situation which causes stress among monkeys which are used to each other's company. The scientists found that, after social separation, the highest levels of stress hormones were found among female animals that both carried the s allele, and had a history of adversity. They say that if their results can be applied to humans they suggest that females who carry the s allele may be particularly vulnerable to developing mood disorders after being exposed to stress early in life, such as childhood abuse or neglect. Researcher Dr Christina Barr told BBC News Online it was unclear why men and women should react differently. However, she said it was possible that sex hormones also play a role. (C)BBC

Keyword: Emotions; Hormones & Behavior
Link ID: 5981 - Posted: 08.11.2004

DURHAM, N.C. — A "stink fight" between ring-tailed lemurs might be dead serious to them. But to observers, the scented struggle ranks among the more odd, even comical sights at the Duke University Primate Center — already renowned for the biological eccentricities of its exotic denizens Preparations for battle begin when male combatants load their "weapons" — vigorously rubbing their tails against their shoulders and between their wrists, infusing the fur with scent from glands there. So armed — or tailed — they launch their attacks, feathery tails arched over their backs, ears flattened and squeaking warnings. They relentlessly flick their tails at one another until one of the adversaries comes to his scentses, gets the odiferous message and retreats. But until the research of Duke biologist Christine Drea and student Elizabeth Scordato, scientists had no idea what chemical messages were being wafted back and forth in such fights. More broadly, they have not understood the complex "language" of multiple scents that lemurs use to communicate a variety of messages from aggression to mating receptiveness.

Keyword: Chemical Senses (Smell & Taste); Language
Link ID: 5980 - Posted: 06.24.2010

Michael Hopkin If you're a loser in the dating game, your name might be part of the problem. New research has revealed that the vowel sounds in your name could influence how others judge the attractiveness of your face. Amy Perfors, a cognitive scientist at the Massachusetts Institute of Technology, who carried out the study, believes the effect is subconscious. Observers unwittingly deem others better looking if they have the right moniker, she says. Perfors made the discovery by posting pictures of 24 friends on hotornot.com, a website that allows users to award marks out of ten for others' attractiveness. Names are not usually displayed with the pictures, but for her experiment Perfors made sure that a name (not necessarily a truthful one) was displayed in the photo's upper corner. She later posted the same photographs with different names, and once again collected the feedback. Average scores for the faces changed depending on the name they were given, Perfors told the annual meeting of the Cognitive Science Society last week in Chicago, Illinois. ©2004 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 5979 - Posted: 06.24.2010

Using a new molecular genetic technique, scientists have turned procrastinating primates into workaholics by temporarily suppressing a gene in a brain circuit involved in reward learning. Without the gene, the monkeys lost their sense of balance between reward and the work required to get it, say researchers at the NIH's National Institute of Mental Health (NIMH). "The gene makes a receptor for a key brain messenger chemical, dopamine," explained Barry Richmond, M.D., NIMH Laboratory of Neuropsychology. "The gene knockdown triggered a remarkable transformation in the simian work ethic. Like many of us, monkeys normally slack off initially in working toward a distant goal. They work more efficiently—make fewer errors—as they get closer to being rewarded. But without the dopamine receptor, they consistently stayed on-task and made few errors, because they could no longer learn to use visual cues to predict how their work was going to get them a reward." Richmond, Zheng Liu, Ph.D., Edward Ginns, M.D., and colleagues, report on their findings in the August 17, 2004 Proceedings of the National Academy of Sciences, published online the week of August 9th.

Keyword: Learning & Memory; Drug Abuse
Link ID: 5978 - Posted: 06.24.2010

By ANNETTE RACOND Certain moments in my life are like sharply focused snapshots that never fade. I was in my flannel pajamas watching TV in my parents' bedroom in Douglaston, N.Y., the day Neil Armstrong stepped onto the moon. More than a decade later, when news broke of John Lennon's death, I was cramming for a test in my dorm room at Boston University. On April 1, 2004, I had another such moment: My mother called to tell me that Jeff Matovic, a 31-year-old husband and father from Lyndhurst, Ohio, had become the first person with Tourette's syndrome in the United States to be treated with deep brain stimulation. His doctors say the procedure has so far relieved Mr. Matovic of the tics that came with his disorder. He is no longer a constant prisoner to the abrupt and repetitive muscle movements and vocalizations that made his life unbearable. Mr. Matovic can now experience the beauty of stillness. As a fellow Tourette's syndrome sufferer, Mr. Matovic's story has given me hope that maybe I, too, can be freed from my tics, twitches, bobs, nods, grunts, squirms, hiccups and jolting motions. Even though I exhibited symptoms of Tourette's syndrome at age 6, the disorder was not diagnosed until I was 28. Copyright 2004 The New York Times Company

Keyword: Tourettes
Link ID: 5977 - Posted: 08.10.2004

By JOHN LANGONE At on time or another, every child experiences sadness, anger and loneliness, and displays a range of odd mannerisms. When these normal feelings are overwhelming and interfere with their daily lives, the behavior has become a disorder. Autism and Asperger's syndrome are closely related pervasive developmental disorders. Asperger's is often less severe, but both are marked, among other characteristics, by flawed social interaction and repetitive behavior. Many autistic children never learn to speak, and if they do they may speak in odd ways. They also have difficulty making eye contact. Children with Asperger's have normal language skills and I.Q.'s, although their communication skills are impaired. These books provide an empathetic look into the two complex syndromes and into the minds of children who have them, as well as offering guidelines for parents. Dr. Buten, the founder of an autism treatment center outside Paris, suggests that clear definitions and descriptions of autism are frustratingly elusive. Copyright 2004 The New York Times Company

Keyword: Autism
Link ID: 5976 - Posted: 08.10.2004

By BENEDICT CAREY Good therapists usually work to resolve conflicts, not inflame them. But there is a civil war going on in psychology, and not everyone is in the mood for healing. On one side are experts who argue that what therapists do in their consulting rooms should be backed by scientific studies proving its worth. On the other are those who say that the push for this evidence threatens the very things that make psychotherapy work in the first place. Which side prevails may shape not only how young therapists are trained and what techniques practitioners use in the future, but also how tightly health insurers restrict the therapies they are willing to pay for, and thus how much the estimated 20 million Americans who enter psychotherapy each year have to pay out of their own pockets. Ultimately, some experts say, the survival of one-on-one counseling, or talk therapy, as an accepted mode of treatment for mental disorders may hang in the balance. Copyright 2004 The New York Times Company

Keyword: Depression
Link ID: 5975 - Posted: 08.10.2004

What's really going on in a baby's head before he or she is able to talk? "Parents have the propensity to interpret what kids are saying," says Susan Hespos, psychology professor at Vanderbilt University. "So a kid might make a grunting noise and a parent might elaborate that into a full sentence. That's all well and good, but in science, we need objective methods. We wanted to look at infants before they have language and see, do they have thoughts?" One of the ways to explore this is to look at categories that are captured in a language that the infants haven't been exposed to. Hespos used a difference in how two different languages describe space: In Korean, the difference between a "tight fit" and a "loose fit" is marked in the language—a cap on a pen is a tight fit, and a pen on a table is a loose fit. In English, the distinction marked by the language has to do with "support" and "containment"—the ink is in the pen, or the pen is on the table. Hespos wanted to see if infants from native English-speaking homes would notice the loose fit/tight fit distinction. She studied 32 five month olds while they watched hands place a cylinder into tight- or loose-fitting containers. "This is a distinction that if you presented adult English speakers with it, they would gloss over the distinction," Hespos explains. "They wouldn't notice it. It's not captured in our language." © ScienCentral, 2000- 2004.

Keyword: Language
Link ID: 5974 - Posted: 06.24.2010

The difference in size between males and females of the same species is all down to the battle for a mate, according to a study of shorebirds published by British scientists today. The findings, published in the Proceedings of the National Academy of Sciences, are the first explanation for a rule identified over forty years ago by German scientist Bernhard Rensch. Rensch's rule, as it has become known, says that the ratio between the sizes of the sexes is related to body size with very few exceptions throughout the animal kingdom - for example, male gorillas are much bigger than female gorillas, whereas male rats are only slightly larger than female rats. In this new research, scientists from the Universities of Bath, Oxford and East Anglia, carried out complex statistical analyses of the mating behaviour, body size and ecology of more than 100 different shorebird species from around the world. They found that in larger shorebirds the battle between males for a mate is highly competitive and larger size offers an advantage over other potential suitors as they battle aggressively on the ground. The evolutionary result is that male Ruffs, a large shorebird, are about twice the size of females. For smaller species, such as Dunlins, battles take place in the air and agility and smallness become more important factors. The result is that Dunlin males are smaller than the females.

Keyword: Sexual Behavior; Evolution
Link ID: 5973 - Posted: 08.10.2004

That young people tend to eat more beef products is not enough to explain the strikingly high proportion of new-variant Creutzfeldt-Jacob disease cases among children and adolescents. An article published this week in BMC Infectious Diseases, shows that young people must also be more susceptible to vCJD infection because of their age. New detailed estimates of the UK population's dietary exposure to bovine material according to age have recently become available. Pierre-Yves Boëlle and his colleagues from Assistance Publique Hôpitaux de Paris and Université Joseph Fourier, Grenoble plugged this information into a mathematical model that predicts the age distribution of vCJD cases. "We found that exposure alone could not explain the young age of vCJD cases as seen in the UK," said Boëlle. "An additional effect of age-dependent susceptibility was required to fully account for the age of the vCJD cases." If the researchers considered exposure to beef products as the only risk factor, the predicted age distribution did not fit well with the actual age distribution of the 137 reported cases. This model predicted that 48% of those with vCJD are over 40, whereas in reality only 10% of people affected by the disease fall into this age group.

Keyword: Prions
Link ID: 5972 - Posted: 08.10.2004

By Jennifer Viegas, Discovery News — Koko, a 33-year-old gorilla that was taught to communicate using American Sign Language, recently told her caregivers that she desired oral surgery to remove an aching tooth, which was extracted with success on Sunday. The unusual request likely marks the first time that an animal ever has used language created by humans to ask for surgery. Lorraine Slater, development director of the Northern California-based Gorilla Foundation that houses Koko, told Discovery News that the lowland gorilla had been signing about tooth discomfort for a while before she communicated that the pain had become more intense in the past three to four weeks. Slater said Koko's caregivers created a chart containing the numbers one through 10 with corresponding amounts of dots, as the gorilla responds to visual information. Over the past several days, the researchers asked the gorilla on a daily basis to communicate her level of tooth pain. Copyright © 2004 Discovery Communications Inc.

Keyword: Language
Link ID: 5971 - Posted: 06.24.2010

Science can put a dent in the sex life of a scarab beetle by blocking its ability to pick up female scent, according to Walter Leal, professor of entomology at UC Davis. The research could eventually lead to methods to control insect pests without affecting harmless or beneficial insects. "Chemical communication is the prime means of communication in insects," Leal said. If those communications can be controlled in the environment, insect pests could be prevented from breeding, he said. Female pale-brown chaffers, a scarab beetle that is an agricultural pest in Japan, release a chemical signal or pheromone to attract males. Insects smell through their antennae. Inside the antennae, pheromone molecules hit a specific switch that sends a nerve signal to the insect's brain. Before the switch can fire again, it must be reset by removing the pheromone, like a wine-taster rinsing her palate.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 5970 - Posted: 08.10.2004