By Maia Szalavitz It's hardly a secret that taking cocaine can change the way you feel and the way you behave. Now, a study published in the Jan. 8 issue of Science shows how it also alters the way the genes in your brain operate. Understanding this process could eventually lead to new treatments for the 1.4 million Americans with cocaine problems, and millions more around the world. The study, which was conducted on mice, is part of a hot new area of research called epigenetics, which explores how experiences and environmental exposures affect genes. "This is a major step in understanding the development of cocaine addiction and a first step toward generating ideas for how we might use epigenetic regulation to modulate the development of addiction," says Peter Kalivas, professor of neuroscience at the Medical University of South Carolina, who was not associated with the study. (See the top 10 scientific discoveries of 2009.) Though we think about our genes mostly in terms of the traits we pass on to our children, they are actually very active in our lives every day, regulating how various cells in our bodies behave. In the brain this can be especially powerful. Any significant experience triggers changes in brain genes that produce proteins — those necessary to help memories form, for example. But, says the study's lead author, Ian Maze, a doctoral student at Mount Sinai School of Medicine, "when you give an animal a single dose of cocaine, you start to have genes aberrantly turn on and off in a strange pattern that we are still trying to figure out." © 2010 Time Inc.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 13647 - Posted: 06.24.2010

Dopamine, a chemical with a key role in setting people's moods, could have a much wider-ranging impact on their everyday lives, research suggests. Experiments show that altering levels of the chemical in the brain influences the decisions people make. One expert said the results showed the relative importance of "gut feeling" over analytical decision making. The Current Biology study could help understand how expectation of pleasure can go awry, for example in addiction. It follows previous research by the University College London team, which, using imaging techniques, detected a signal in the brain linked to how much someone enjoyed an experience. They found that signal could in turn predict the choices a person made. With the suspicion that the signal was dopamine, the researchers set up a study to test how people make complex decisions when their dopamine system has been tampered with. The 61 participants were given a list of 80 holiday destinations, from Greece to Thailand, and asked to rate them on a scale of one to six. They were then given a sugar pill and asked to imagine themselves in each of 40 of the destinations. Researchers then administered L-Dopa, a drug used in Parkinson's disease to increase dopamine concentrations in the brain, before asking them to imagine the other holidays. They rated all the destinations again, and a day later they were asked where they would prefer to go, out of paired lists of holidays. The extra dopamine gave people higher expectations when rating holiday options. And that translated into the choice of trip they made a day later. Study leader Dr Tali Sharot, from the Wellcome Trust Centre for Neuro-imaging at UCL, said humans made far more complex decisions than other animals, such as what job to take and whether to start a family, and it seemed dopamine played an important part in that. (C)BBC

Keyword: Drug Abuse; Attention
Link ID: 13646 - Posted: 01.09.2010

By Jacqueline Stenson If you’re trying to motivate yourself to get moving in the new year, here’s some added inspiration: Mounting research shows that exercise isn’t just good for the body, it’s also good for the brain — and not just the brains of older folks. While much of the research on the effects of exercise on the mind has focused on countering dementia in seniors, recent studies show that kids and young to middle-aged adults can get a brain boost as well. One large new study, for instance, found that teenage males in the best cardiovascular shape performed better on various cognitive tests at age 18 than their less fit counterparts. And those who improved their fitness levels between the ages of 15 and 18 achieved higher test scores than those who decreased their fitness during that time. What’s more, the fittest 18-year-olds were more likely to achieve both higher educational and socioeconomic status later in life, according to results published in December in the Proceedings of the National Academy of Sciences. “We cannot determine from this study alone that physical fitness causes better cognitive functioning,” says study author Georg Kuhn, a professor at the Center for Brain Repair and Rehabilitation at the University of Gothenburg in Sweden. “But taken together with other studies, we can assume that better cardiovascular fitness may optimize cognitive performance and academic achievements.” © 2010 msnbc.com

Keyword: Learning & Memory; Alzheimers
Link ID: 13645 - Posted: 06.24.2010

By Emily Laut When it came to insect penises, Charles Darwin had it right. The famed naturalist suspected that insect genitalia, which are frequently festooned with bizarre combinations of hooks, spines, and knobs, essentially functioned like peacock tails. That is, they helped males beat out their rivals for females. Now, researchers have confirmed this hypothesis by zapping fly penises with a laser. Darwin's hypothesis relies on something called preinsemination sexual selection. Basically, the idea holds that the male with the most effective strategy for getting a female to mate with him--attractive plumage, for instance--is most likely to pass on his genes to the next generation. But since then, studies in various insects have suggested that sexual selection can happen during or even after mating. Researchers noticed, for example, that certain flies engage in courtship displays only after copulation has begun, perhaps as a way to get the female to favor a male's sperm over that of his competitors. (Female flies typically mate with multiple males over a short time period.) They also reasoned that the complicated penis ornaments might help sweep away other males' sperm during mating. But there was no direct way to test this. Enter laser beams. Evolutionary ecologist Michal Polak of the University of Cincinnati in Ohio and entomologist Arash Rashed now of the University of California, Berkeley, modified a laser commonly used to cut very small things, like the nerve cells of nematodes, so that it could zap off the hooks on fruit fly penises. "We can cut the tiniest of structures with the highest of precision," says Polak, all without harming the fly. © 2010 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 13644 - Posted: 06.24.2010

By ANDREW POLLACK It seemed like the offer of a lifetime — earn $2,500 by flying to France aboard a private luxury jet. Even if it wins Food and Drug Administration approval, Nuvigil would have to compete with cheap jet-lag treatments like coffee. But as the fine print made clear, there would be no Eiffel Tower or chateaux, no foie gras or Bordeaux. Travelers were confined to a laboratory in either Toulouse or Rouffach with electrodes attached to their heads, testing whether a drug could keep their jet-lagged bodies awake. That drug, Nuvigil from Cephalon, could become the first medicine specifically approved by the Food and Drug Administration to combat jet lag. A jet-lag antidote might seem to be the latest lifestyle drug, a further step in the “medicalization” of something that is not an illness. But sleep specialists, who call the affliction “jet lag disorder,” say that while not exactly a disease, it is a condition that can be dangerous — as when someone tries to drive a car right after arriving in a distant time zone. For Cephalon, a company in Frazer, Pa., whose business tactics have attracted federal attention, the approval for jet lag is part of a plan to extend patent protection for its core franchise in stay-awake drugs. Copyright 2010 The New York Times Company

Keyword: Biological Rhythms; Sleep
Link ID: 13643 - Posted: 06.24.2010

By Sam Kean Here we go again. Late last year, scientists seemed to be homing in on the cause of chronic fatigue syndrome (CFS)—excessive tiredness and other symptoms that have no known biological cause--by finding a supposed viral link. But a new paper challenges that link, a development that may plunge the field back into the same confusion and acrimony that has characterized it for years. Many CFS patients report that their symptoms began after an acute viral infection. Yet scientists have been unable to pin CFS on common viruses such as the Epstein-Barr virus. As a result, patients have faced skepticism for years that CFS might not be a real disease, or that it is perhaps a psychiatric disorder. A team of American researchers thought it finally struck pay dirt last October when it reported in Science that it found DNA traces of a virus in the blood cells of two-thirds of 101 patients with CFS, compared with 4% of 218 healthy controls. XMRV is a rodent retrovirus also implicated in an aggressive prostate cancer, though why it might cause or be associated with CFS remains unclear. Other scientists were dubious about the XMRV connection. They criticized the Americans for not explaining enough about the demographics of their patients and the procedures to control for contamination. Several virologists around the world practically sprinted to their labs to redo the experiments, and the discovery that a clinic associated with the Science paper was selling a $650 diagnostic test for XMRV made the issue more pressing. A British team already exploring the XMRV-prostate cancer link won the race, submitting a paper to debunk the claim on 1 December. © 2010 American Association for the Advancement of Science

Keyword: Depression; Emotions
Link ID: 13642 - Posted: 06.24.2010

By Marla Cone and Environmental Health News California scientists have discovered clusters of autism, largely in the Los Angeles and San Francisco areas, where children are twice as likely to have autism as children in surrounding areas. The 10 clusters were found mostly among children with highly educated parents, leading researchers to report that they probably can be explained by better access to medical experts who diagnose the disorder. Because of the strong link to education, the researchers from University of California at Davis said the new findings do not point to a localized source of pollution, such as an industry, near the clusters. “I suspect access to services plays the major role,” said Irva Hertz-Picciotto, senior author of the study published Tuesday in the journal Autism Research. She added, however, that there could be other reasons why higher-educated parents lead to more autism. Environmental exposures, such as chemicals from consumer products, could be more common in those households, she said. “Certainly there may be some consumer products to which more educated persons are more likely to be exposed. There is undoubtedly a possibility of higher exposures in the more educated,” said Hertz-Picciotto, a professor of public health sciences and an autism expert at the UC Davis MIND Institute. For the study, the researchers analyzed the birth records of about 2.5 million babies born in California between 1996 and 2000. Nearly 10,000 were later diagnosed with an autism spectrum disorder. © 2010 Scientific American,

Keyword: Autism
Link ID: 13641 - Posted: 06.24.2010

By Carina Storrs Wolfing down a meal in record time can lead to more than digestive discomfort and possible acclaim in food-eating contests. Studies have warned that speed eaters can easily become overeaters, possibly because they lose track of how sated they are amidst hurried bites. Moreover, the pattern of consuming large portions of food quickly is associated with obesity in children, adolescents and adults. Researchers in Bristol, England, sought to break this pattern in children and adolescents using a machine dubbed the Mandometer, which is designed to manage the pace of meals. The device features a computerized scale that calculates the rate of food intake and, like a hovering mother, constantly reminds the user if he or she should eat slower or faster. The device, first developed to help treat anorexia and bulimia nervosa, actually issues verbal feedback. In a study published January 5 in the British Medical Journal, participants who received Mandometer assistance for one year lost significantly more body mass index (BMI), which is a measure of weight based on height, than those who did not. In fact, the Mandometer group, but not the control group, achieved the reduction in BMI that the authors had previously determined was necessary to lead to a difference in body composition and metabolism. The finding suggests that "modifying eating behavior might provide additional benefits to standard lifestyle modification in treating obese adolescents," the authors wrote, noting that adolescents have been more difficult to treat for obesity through counseling than younger children. The study was led by Julian P.H. Shield, a professor of diabetes and metabolic endocrinology at the University of Bristol. © 2010 Scientific American,

Keyword: Obesity; Development of the Brain
Link ID: 13640 - Posted: 06.24.2010

The female cane toad can pump herself up to mega-size to throw off smaller males striving to mate with her, Australian biologists reported on Wednesday. The unusual tactic suggests that female anurans, as frogs and toads are called, may have far more power to select their sex partner than thought, according to their study, appearing in the British journal Biology Letters. Female cane toads (Bufo marinus) are typically choosier than males when it comes to reproduction. They discriminate among potential mates by approaching the toad with the best call. But, as they head to a rendezvous with the hunk with the mightiest ribbit, they also have to run the gauntlet of excited rival males. An unwanted suitor will seek to climb on the female's back, grasping her tightly in the armpit or groin, waiting until she starts laying her eggs in order to fertilize them. This is where the pneumatic trick comes in, say the scientists, led by Benjamin Phillips of the University of Sydney. By inflating sacs in her body, the female is able to loosen the grip and the luckless male slides off her body, defeated. © 2009 Discovery Communications, LLC.

Keyword: Sexual Behavior
Link ID: 13639 - Posted: 06.24.2010

Aggressive childhood brain tumours could be treatable with a novel combination of two existing cancer drugs, a study suggests. Researchers led by the Institute of Cancer Research (ICR) examined 90 tumours from children and found two new genetic abnormalities in nine of them. They were then able to kill these abnormal tumours, in laboratory tests, by combining the two existing drugs. But one expert says the findings remain "far off being applicable to patients". In the UK, about 400 children are diagnosed with brain tumours every year. The research, published in the journal Clinical Cancer Research, brought together scientists from the UK, France, Portugal, Brazil and America. The abnormal tumours - known as glioblastomas, aggressive and often fatal cancers of the brain's glial cells - contained too many copies of the EGFR gene and mutations of the gene the scientists say have never before been found in children. They tried to block the EGFR gene with a drug, erlotinib (Tarceva), used in clinical trials to treat adult glioblastomas, but identified a molecule specific to the children's cells - platelet-derived growth factor receptor (PGFR) - that was making it ineffective. But when they combined erlotinib with a drug, imatinib (Glivec), they hoped would block the PGFR molecules, they killed a significant number of the cancer cells. Dr Chris Jones, who led the research, said it proved "that cancers may look the same, but it is only when you get down to the genetic level that you can truly understand them and devise treatments". (C)BBC

Keyword: Development of the Brain; Glia
Link ID: 13638 - Posted: 01.05.2010

A Canadian-led study has found that men's minds and bodies are more in sync than women's when it comes to sexual arousal. The analysis of previous research on human sexuality found that men's feelings of arousal tend to match their physiological responses, while women's mind and body responses were more often inconsistent. Psychology professor Meredith Chivers of Queen's University led the study, which included researchers from the Royal Ottawa Health Care Group, the University of Lethbridge, the University of Amsterdam and the Ontario Institute for Studies in Education at the University of Toronto. "We wanted to discover how closely people's subjective experience of sexual arousal mirrors their physiological genital response — and whether this differs between men and women," Chivers said in a statement. The researchers analyzed the results from 134 previous studies, conducted between 1967 and 2007, collectively involving more than 2,500 women and 1,900 men. Participants in the studies were asked how aroused they felt while watching or listening to sexually explicit content, and sometimes after the exposure to the sexual stimulus. The researchers then compared these descriptions of the participants' feelings with their physiological responses: changes in erection for men and in genital blood flow in women. © CBC 2010

Keyword: Sexual Behavior
Link ID: 13637 - Posted: 06.24.2010

About half of Americans with major depression do not receive treatment for the condition, and in many cases the therapies are not consistent with the standard of care, according to a new study. The study also showed that ethnicity and race were important factors in determining who received treatment, with Mexican Americans and African Americans the least likely to have depression care. While many people can feel sad from time to time, a depressive disorder occurs when these feelings start to interfere with everyday life, preventing someone from functioning normally, according to the National Institutes of Health (NIH). The condition can be debilitating, hindering a person's ability to work, sleep and eat. A combination of factors likely contributes to the disorder, including imbalances in brain chemicals, genetics, and stressful situations, the NIH says. Story continues below ↓advertisement | your ad here Previous research has indicated that many Americans with depression go untreated, but the current study was the first to break down large ethnic and racial groups into subgroups to look at disparities in treatment. The researchers used information from the National Institute of Mental Health's Collaborative Psychiatric Epidemiology Surveys — a combination of three surveys conducted between 2001 and 2003 with a total of 15,762 participants. © 2010 LiveScience.com.

Keyword: Depression
Link ID: 13636 - Posted: 06.24.2010

By BENEDICT CAREY That most alarming New Year’s morning question — “Uh-oh, what did I do last night?” — can seem benign compared with those that may come later, like “Uh, what exactly did I do with the last year?” Or, “Hold on — did a decade just go by?” It did. Somewhere between trigonometry and colonoscopy, someone must have hit the fast-forward button. Time may march, or ebb, or sift, or creep, but in early January it feels as if it has bolted like an angry dinner guest, leaving conversations unfinished, relationships still stuck, bad habits unbroken, goals unachieved. “I think for many people, we think about our goals, and if nothing much has happened with those then suddenly it seems like it was just yesterday that we set them,” said Gal Zauberman, an associate professor of marketing at the Wharton School of Business. Yet the sensation of passing time can be very different, Dr. Zauberman said, “depending on what you think about, and how.” In fact, scientists are not sure how the brain tracks time. One theory holds that it has a cluster of cells specialized to count off intervals of time; another that a wide array of neural processes act as an internal clock. Either way, studies find, this biological pacemaker has a poor grasp of longer intervals. Time does seem to slow to a trickle during an empty afternoon and race when the brain is engrossed in challenging work. Stimulants, including caffeine, tend to make people feel as if time is passing faster; complex jobs, like doing taxes, can seem to drag on longer than they actually do. Copyright 2010 The New York Times Company

Keyword: Attention; Learning & Memory
Link ID: 13635 - Posted: 06.24.2010

By Rachel Saslow Scientists may have created a vaccine against cocaine addiction: a series of shots that changes the body's chemistry so that the drug can't enter the brain and provide a high. The vaccine, called TA-CD, shows promise but could also be dangerous; some of the addicts participating in a study of the vaccine started doing massive amounts of cocaine in hopes of overcoming its effects, according to Thomas R. Kosten, the lead researcher on the study, which was published in the Archives of General Psychiatry in October. "After the vaccine, doing cocaine was a very disappointing experience for them," said Kosten, a professor of psychiatry and neuroscience at Baylor College of Medicine in Houston. Nobody overdosed, but some of them had 10 times more cocaine coursing through their systems than researchers had encountered before, according to Kosten. He said some of the addicts reported to researchers that they had gone broke buying cocaine from multiple drug dealers, hoping to find a variety that would get them high. Of the 115 addicts in the study, 58 were given the vaccine, administered in a series of five shots over 12 weeks, while 57 received placebo injections. Six people dropped out before the end of the study. The researchers recruited the participants from a methadone-treatment program in West Haven, Conn., which made it possible to track them for the full 24 weeks of the study. The patients were addicted to cocaine and heroin; TA-CD is designed to work only on cocaine, including the crack form of the drug. © 2010 The Washington Post Company

Keyword: Drug Abuse
Link ID: 13634 - Posted: 06.24.2010

By HENRY FOUNTAIN Subjective tinnitus, the ringing or other noise that often accompanies noise-related hearing loss, is a tough problem to treat. But researchers in Germany have come up with a novel approach, a kind of music therapy in which the music is custom-tailored to the person with tinnitus. The technique, by Hidehiko Okamoto, Henning Stracke and Christo Pantev of Westfalian Wilhelms-University and Wolfgang Stoll of Muenster University Hospital, makes use of recent findings about a possible cause of tinnitus: reorganization of the auditory cortex, the part of the brain responsible for perceiving sound, in response to noise exposure. Other research has shown that behavioral training may reverse faulty cortical reorganization. The researchers allowed patients to choose their favorite music, which was then “notched” — a one-octave frequency band, centered on the frequency of the ringing experienced by the subject, was filtered out. The subjects listened to the music on average about 12 hours a week. After a year, the researchers report in The Proceedings of the National Academy of Sciences, those who listened to this custom-notched music reported a significant improvement in their tinnitus — the ringing was not as loud — compared with others who listened to music that was notched at frequencies not corresponding to their ringing frequency. Copyright 2010 The New York Times Company

Keyword: Hearing
Link ID: 13633 - Posted: 06.24.2010

By Bruce Bower She’s the ultimate evolutionary party crasher. Dubbed Ardi, her partial skeleton was unearthed in Ethiopia near the scattered remains of at least 36 of her comrades. Physical anthropologists had known about the discovery of this long-gone gal for around 15 years, but few expected to see the 4.4-million-year-old hell-raiser that was unveiled in 11 scientific papers in October. Like a biker chick strutting into a debutante ball, Ardi brazenly flaunts her nonconformity among more-demure members of the human evolutionary family, known as hominids. She boasts a weird pastiche of anatomical adornments, even without tattoos or nose studs. In her prime, she moved slowly, a cool customer whether upright or on all fours. Today, she’s the standard bearer for her ancient species, Ardipithecus ramidus. And in true biker-chick fashion, Ardi chews up and spits out conventional thinking about hominid origins, according to a team — led by anthropologist Tim White of the University of California, Berkeley — that unearthed and analyzed her fragile bones (SN: 10/24/09, p. 9). First, White and his colleagues assert, Ardi’s unusual mix of apelike and monkeylike traits demolishes the long-standing assumption that today’s chimpanzees provide a reasonable model of either early hominids or the last common ancestor of people and chimps — an ancestor which some scientists suspect could even have been Ardi, if genetics-based estimates of when the split occurred are borne out. Second, the team concludes, Ardi trashes the idea that knuckle-walking or tree-hanging human ancestors evolved an upright gait to help them motor across wide ancient savannas. Her kind lived in wooded areas and split time between lumbering around on two legs hominid-style and cruising carefully along tree branches on grasping feet and the palms of the hands. © Society for Science & the Public 2000 - 2010

Keyword: Evolution
Link ID: 13632 - Posted: 06.24.2010

by Carla K. Johnson , Associated Press An expert panel says there's no rigorous evidence that digestive problems are more common in children with autism compared to other children, or that special diets work, contrary to claims by celebrities and vaccine naysayers. Painful digestive problems can trigger problem behavior in children with autism and should be treated medically, according to the panel's report published in the January issue of Pediatrics and released Monday. "There are a lot of barriers to medical care to children with autism," said the report's lead author, Dr. Timothy Buie of Harvard Medical School. "They can be destructive and unruly in the office, or they can't sit still. The nature of their condition often prevents them from getting standard medical care." Some pediatricians' offices "can't handle those kids," Buie said, especially if children are in pain or discomfort because of bloating or stomach cramps. Pain can set off problem behavior, further complicating diagnosis, especially if the child has trouble communicating -- as is the case for children with autism. Autism is a spectrum of disorders affecting a person's ability to communicate and interact with others. Children with autism may make poor eye contact or exhibit repetitive movements such as rocking or hand-flapping. About 1 in 110 U.S. children have autism, according to a recent government estimate. © 2009 Discovery Communications, LLC.

Keyword: Autism
Link ID: 13631 - Posted: 06.24.2010

Scientists have developed biological cells that can give insight into the chemistry of the brain. The cells, which change colour when exposed to specific chemicals, have been used to show how a class of schizophrenia drug works. The researchers hope they will also help shed light on how many other drugs work on the brain. The study, by the University of California - San Diego, is published in Nature Neuroscience. Schizophrenia is most commonly associated with symptoms such as delusions and hallucinations. But people with the illness also struggle to sustain attention or recall information. A class of drugs called atypical neuroleptics has become commonly prescribed, in part because they seem to improve these problems. However, the way they altered brain chemistry was uncertain. It was known that the drugs trigger the release of a large amount of a chemical called acetylcholine, which enables brain cells to communicate with each other. However, the drugs have also been shown to hobble a receptor on the surface of the receiving cell, which would effectively block the message. The San Diego team designed biological cells - called CNiFERs - which changed colour when acetylcholine latched onto this particular class of receptors - an event scientists have not previously been able to detect in a living brain. They implanted the cells into rat brains, then stimulated a deeper part of the brain in a way known to release acetylcholine nearby. In response, CNiFERs changed colour - proving that they were working. (C)BBC

Keyword: Schizophrenia
Link ID: 13630 - Posted: 01.04.2010

By Carolyn Y. Johnson Dogs have been an integral part of human life for centuries. It is precisely because of that intertwined history that dogs are a potentially powerful tool for researchers seeking the genetic roots of everything from psychiatric disorders to cancer - just two of the ailments that are similar in both humans and dogs. Last month, scientists studying Doberman pinschers with a compulsive behavior disorder similar to human obsessive-compulsive disorder found a gene associated with the condition. The genetic hit is now being followed by other researchers, who are studying the same gene in human patients with OCD, in hopes the clue from man’s best friend may help explain the disease in people. “This is exactly where we were hoping to get to,’’ said Elinor Karlsson, a postdoctoral fellow at the Broad Institute, a genetics research center in Cambridge, and coauthor of a paper on the subject. “This is taking a disease that people have had a lot of trouble working with in humans, that seems to be a multigenic and complex psychiatric disease, and using a dog breed to look at something completely new about that disease - something we wouldn’t be able to find in any other species.’’ In dogs, compulsive behavior includes tail chasing, licking their legs until they develop infections, and pacing and circling - versions of normal behaviors such as predatory behavior, grooming, or locomotion taken to extremes. Those kinds of behaviors parallel the way that normal human behaviors, such as hand washing or checking objects, can become repetitive in the estimated 2.2 million American adults affected by OCD. © 2010 NY Times Co

Keyword: OCD - Obsessive Compulsive Disorder; Genes & Behavior
Link ID: 13629 - Posted: 06.24.2010

What if you wanted to get to know your brain by building one from the bottom up? All you need is this guide, a lot of patience, and some really tiny tweezers.

Keyword: Development of the Brain
Link ID: 13628 - Posted: 01.04.2010