Atlanta, - The neurotransmitter dopamine continues to be released for nearly an hour after neurons are stimulated, suggesting the existence of secondary mechanisms that allow for sustained availability of dopamine in different regions of the brain including areas critical for memory consolidation, drug induced plasticity and maintaining active networks during working memory, according to a University of Pittsburgh study being presented today at the 36th Annual Meeting of the Society for Neuroscience, held at the Georgia World Congress Center in Atlanta. Determining the mechanisms that cause what is being called "post-stimulus activated release" and how they maintain dopamine levels could have important implications for understanding and treating neurological and psychiatric disorders caused by an imbalance of dopamine function including schizophrenia, attention deficit hyperactivity disorder, Tourette's syndrome, Parkinson's disease and addiction. According to Bita Moghaddam, Ph.D., professor of neuroscience and psychiatry, who led the study, in addition to its clinical benefits, post-stimulus activated release can be used to explain how brief events that activate neurons for short periods of time can influence brain function long after the events. For example, it can be used to explain how smelling freshly baked cookies could evoke childhood memories of spending time with a beloved grandparent, leading a person to reminisce long after the smell is gone and take the unplanned or impulsive action of baking or buying cookies.

Keyword: Miscellaneous
Link ID: 9475 - Posted: 10.16.2006

Kerri Smith The battle of the sexes continues to rage — right down to the level of our genes. A gene has now been discovered that, when mutated, turns girls into boys. The finding advances, but also complicates, our understanding of how sex is determined by our genes. In people, almost all men carry two different sex chromosomes (XY) and women are XX. But there are some (extremely rare) exceptions to this rule. It is possible to have XX men, for example. This female-to-male sex reversal almost always happens when a certain gene called SRY, usually carried on the Y chromosome, accidentally ends up on the X chromosome inherited from the father. Other genes have been found to muddle up sexual identity, making the resulting child neither fully male nor fully female. But in most cases of anatomically complete XX men — who have functional testes, but without a Y are infertile — SRY is involved. For this reason, it has long been called the gene that defines 'maleness'.1 ©2006 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 9474 - Posted: 06.24.2010

Ayla Arslan When we look at a banana, does our brain tell us it looks yellow, even if it isn't? A recent study shows that it does. Psychologists at the University of Giessen, Germany, report in Nature Neuroscience that our perception of an object's colour depends on our memory of its typical colour. Karl Gegenfurtner and his co-workers showed their subjects digitized images of fruit, presented in random colours against a grey background. They then asked observers to adjust the colour of the fruit on the computer screen until it too was grey. But the volunteers had a hard time doing this. With a picture of a banana, for example, they would adjust the colour to be slightly too blue when trying to achieve grey, as if compensating for a perception of yellow that wasn't really there (blue is opposite yellow on the colour wheel). At the point at which the banana was truly achromatic, volunteers thought it still looked a bit yellow. ©2006 Nature Publishing Group

Keyword: Vision
Link ID: 9473 - Posted: 06.24.2010

Roxanne Khamsi Prozac can make “adolescent” hamsters more aggressive towards their cage-mates, despite the antidepressant drug producing the opposite effect in adult hamsters, making them calmer. The new findings may help explain why certain antidepressants appear to cause irritability and other abnormal behaviours in teenagers. Kereshmeh Taravosh-Lahn at the University of Texas at Austin, US, and colleagues gave injections of the drug fluoxetine (sold in pill form as Prozac) to pubescent and mature hamsters. They injected either a low dose (10 milligrams per kilo of body weight) or a high dose (20 milligrams per kilo body weight), while other hamsters received a placebo. The researchers then introduced a smaller, same-sex hamster into the cage of each experimental hamster and filmed all the fights between the two rodents that were initiated by the subject animals. None of the fights resulted in the skin-breaks or injury to the animals, the researchers stress. As expected, the pubescent hamsters on a higher dose of drug appeared calmer, initiating about 65% fewer attacks than those on placebo. But surprisingly, those on the lower dose of antidepressant became more aggressive, initiating 40% more fights than those on placebo. Watch a short movie of the aggression in action. Adult hamsters on either dose of the drug initiated fewer fights than those on placebo. © Copyright Reed Business Information Ltd

Keyword: Aggression; Depression
Link ID: 9472 - Posted: 06.24.2010

Regions of the brain may not communicate with each other as efficiently as they should in people with autism, research suggests. US scientists used sophisticated scans to examine connections in the cerebral cortex - the part of the brain that deals with complex thought. They found evidence of abnormal patterns of brain cell connection in people with autism. The research was presented at a meeting of the Society for Neuroscience. In some parts of the cortex brain cells made too many connections, and in other parts not enough. Lead researcher Dr Michael Murias, from the University of Washington, said: "Our findings indicate adults with autism show differences in coordinated neural activity, which implies poor internal communication between the parts of the brain." The researchers analyzed electroencephalography (EEG) scans from 36 adults, half of who had autism. The EEGs, which measure the activity of hundreds of millions of brain cells, were collected while the people were seated and relaxed with their eyes closed for two minutes. The researchers found people with autism particularly showed abnormal patterns of brain cell connection in the temporal lobe, which deals with language. They argue that the abnormal patterns suggest inefficient and inconsistent communication inside the brains of people with autism. Dr Marius said their work might lead to a way to spot autism at an earlier stage. (C)BBC

Keyword: Autism
Link ID: 9471 - Posted: 10.15.2006

By ABBY ELLIN IT’S almost impossible to turn on the television and not glimpse Suzanne Somers smiling back at you. In the last week, she has appeared on the “Today” show, “The View” and “Entertainment Tonight.” She has chatted with Martha Stewart and bonded with Bill O’Reilly. She is not discussing the war in Iraq, nor offering opinions on the Mark Foley scandal. Her latest book, “Ageless: The Naked Truth About Bioidentical Hormones,” hit stores on Oct. 10, and Ms. Somers is simply doing what celebrities do these days: selling. She happens to be good at it. The actress made the ThighMaster a household product and, of the 13 books she has written, 7 have been best sellers. If history — and a good marketing plan — has anything to do with it, “Ageless” may just be her eighth. It is a paean to bioidentical hormone replacement therapy, a controversial treatment for menopausal women that she dubs “the juice of youth.” “I had bone loss 10 years ago — I restored it with bioidenticals,” Ms. Somers, who turns 60 on Monday, said in a telephone interview from Houston, where she was speaking before a group of 1,100 pharmacists. They also recharged her libido, she said, reduced her depression, and rejuvenated her hair, skin and body. (In February 2001, National Enquirer photographed her leaving a plastic surgery clinic, and she subsequently admitted to having had liposuction on her upper back and hips.) The book, though, has raised the hormone levels of at least seven medical doctors. The doctors — three of whom are quoted in the book — generally support the concept of bioidentical hormone therapies but say that too little research has been done to assure that they are safe. Copyright 2006 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 9470 - Posted: 06.24.2010

Brain research will get a boost tomorrow (14 October) as CSIRO launches in the United States its HCA-Vision nerve cell analysis software at Neuroscience 2006 in Atlanta, Georgia, the world's largest conference for brain researchers. HCA-Vision is based on a proprietary mathematical method, patented by Australia’s CSIRO, for automatically tracing and measuring lines in complex images. With up to 40,000 delegates expected, the conference will be an ideal focus for the software’s international launch. Dr Pascal Vallotton, Leader of Biotech Imaging at CSIRO Mathematical and Information Sciences says there are few images more complex than the intricate, web-like branches of nerve cells photographed down a microscope. HCA-Vision allows researchers to reliably measure significant features of cells' appearance as they change in response to drugs, biochemicals or diseases like dementia. “A version of the software for 3D images is under development and will provide 'another dimension' of detail for researchers about nerve cell change.”“Benchmarking studies have shown that the software can do this one hundred times faster than a person using manual tracing methods can,” said Dr Vallotton.

Keyword: Brain imaging
Link ID: 9469 - Posted: 06.24.2010

Atlanta ( — They may be black and white, but new research at the Georgia Institute of Technology and Zoo Atlanta shows that giant pandas can see in color. Graduate researcher Angela Kelling tested the ability of two Zoo Atlanta pandas, Yang Yang and Lun Lun, to see color and found that both pandas were able to discriminate between colors and various shades of gray. The research is published in the psychology journal Learning and Behavior, volume 34 issue 2. “My study shows that giant pandas have some sort of color vision,” said Kelling, graduate student in Georgia Tech’s Center for Conservation Behavior in the School of Psychology. “Most likely, their vision is dichromatic, since that seems to be the trend for carnivores.” Vision is not a well-studied aspect of bears, including the giant pandas. It has long been thought that bears have poor vision, perhaps, Kelling said, because they have such excellent senses of smell and hearing. Some experts have thought that bears must have some sort of color vision as it would help them in identifying edible plants from the inedible ones, although there’s been little experimental evidence of this. However, one experiment on black bears found some evidence that bears could tell blue from gray and green from gray. Kelling used this study’s design as the basis to test color vision in Zoo Atlanta’s giant pandas. ©2006 Georgia Institute of Technology

Keyword: Vision
Link ID: 9468 - Posted: 06.24.2010

ATLANTA – A novel look at the brains of adults with autism has provided new evidence that various brain regions of people with the developmental disorder may not communicate with each other as efficiently as they do in other people. Researchers from the University of Washington's Autism Center will report today at the annual meeting of the Society for Neuroscience on the first study that measures neural activity by using high-resolution electroencephalography (EEG) to examine connections in the cerebral cortex, the part of the brain that deals with higher cognitive processes. Compared to normally developing individuals, the scientists found patterns of abnormal connectivity between brain regions in people with autism. These abnormalities showed both over and under connectivity between neurons in different parts of the cortex, according to Michael Murias, a postdoctoral researcher who headed the study. "Our findings indicate adults with autism show differences in coordinated neural activity," said Murias, "which implies poor internal communication between the parts of the brain." The UW researchers analyzed EEGs from 36 adults, ranging in age from 19 to 38. Half the adults had autism and all had IQs of at least 80. The EEGs, which measure the activity of hundreds of millions of brain cells, were collected with an array of 124 electrodes while the people were seated and relaxed with their eyes closed for two minutes.

Keyword: Autism; Brain imaging
Link ID: 9467 - Posted: 06.24.2010

Gaia Vince Methamphetamine may protect the brain after a stroke, according to new research in rats and gerbils. The illicit street drug – also known as speed – helped reduce brain damage when used up to 16 hours after stroke, potentially widening the window of opportunity for drug intervention. Researchers induced strokes in gerbils, causing them to become twice as active and agitated as normal gerbils. But when the animals were given a low dose of methamphetamine up to 16 hours after the event, the animals became calmer. Dissection later showed that the neurons of the gerbils given methamphetamine were as intact as in animals that had not suffered stroke. “Methamphetamine is a drug that has been shown to exacerbate stroke damage when administered before a stroke, but we have seen roughly 80% to 90% protection of neurons when administered after a stroke,” says Dave Poulsen, who led the research at the University of Montana in the US. The team also looked at slices of rat brain taken from the hippocampus – a region involved in memory and learning – which they kept in a nutritious culture for nine days. The slices were then deprived of glucose and oxygen for 90 minutes to mimic the conditions of a stroke. © Copyright Reed Business Information Ltd

Keyword: Stroke; Drug Abuse
Link ID: 9466 - Posted: 06.24.2010

By BENEDICT CAREY The drugs most commonly used to soothe agitation and aggression in people with Alzheimer’s disease are no more effective than placebos for most patients, and put them at risk of serious side effects, including confusion, sleepiness and Parkinson’s disease-like symptoms, researchers are reporting today. The report, based on a large government comparison of the drugs’ effectiveness, challenges current practice so sharply that it could quickly alter prescribing habits, some experts said. About 4.5 million Americans suffer from the progressive dementia of Alzheimer’s disease, and most patients with the advanced disease exhibit agitation or delusions at some point. The drugs tested in the study — Zyprexa from Eli Lilly; Seroquel from AstraZeneca; and Risperdal from Janssen Pharmaceutical — belong to a class of medications known as atypical antipsychotics. The drugs are used to treat schizophrenia and other psychoses, and are commonly prescribed for elderly patients in long-term care facilities. About a third of the estimated 2.5 million Medicare beneficiaries in nursing homes in the United States have taken the medications, researchers found. And the use of atypical antipsychotics in the elderly accounts for an estimated $2 billion in the annual sales of the drugs, much of the cost paid by Medicare and Medicaid. Copyright 2006 The New York Times Company

Keyword: Alzheimers; Schizophrenia
Link ID: 9465 - Posted: 06.24.2010

By Faye Flam Recent efforts to pass amendments that define marriage as a union between a "man" and a "woman" are going to run into more than just political opposition. Scientists are contending there's no clear definition of the gender divide. There are at least seven definitions, but not everyone qualifies as male or female across the board, says Galdino Pranzarone, a psychologist at Roanoke College who has argued against marriage amendments on the editorial pages of the Roanoke Times. Some people are born with a mix of male and female characteristics. The incidence of intersex births is between one in 1,000 to one in 2,500, says Pranzarone. "That's a lot of people." Alice Dreger, part of the medical humanities and bioethics faculty at Northwestern University, has also written on the flaws of the "one man and one woman" equation. You could define the sexes by their sex organs, Dreger says, but those are vulnerable to birth defects, accidents or cancer. Not to mention that some people have an organ whose size fits somewhere between a small penis and a large clitoris. You might think you could get out a microscope and use chromosomes, defining men as having an X and a Y, women as having two X's. It's simple enough except some people have just a single X, or XXY, or XYY. There are XX men, XY women, and people with a "mosaic" of genetically male and female cells.

Keyword: Sexual Behavior
Link ID: 9464 - Posted: 10.13.2006

by Olivia Judson I met a leopard gecko the other day. He sat on my hand, scarcely moving, for a full 15 minutes. So we took a good look at each other—I gazed into his still, dark eyes, and he seemed to gaze at mine. He was unlike any gecko I had seen before. He had smooth, pale skin spattered with dark spots, a large wedge-shaped head and a tail of pronounced fatness. (He cannot, however, walk on ceilings—unusually for a gecko, he doesn't have adhesive feet.) But the fatness of his tail and the non-stickiness of his feet were not the reasons I was interested to meet him. My interest stems from the fact that leopard geckos—more formally known as Eublepharis macularius—provide the clearest example of how the early environment can sculpt the brain and affect sexual desire. Leopard geckos breed easily in captivity. Which is lucky; to encounter one in the wild, you'd have to head to the rocky deserts and arid badlands of Iraq, Iran, Pakistan and Afghanistan. There, they snooze in burrows during the infernal heat of the day, and venture forth at night to dine on insects, spiders and scorpions. As is often the case for lizards, leopard geckos have their sex determined by the temperature at which the eggs develop. The particular temperatures vary from one species to another. In leopard geckos, eggs incubated at 26° C (78.8° F) all hatch female. At 30° C (86° F), 30% of the eggs will hatch male and 70% female. Raise the temperature another 2.5° C, and that sex ratio flips—a third of the geckolings will be female and two-thirds, male. But go up another 1.5° C and 95% of hatchlings will be female. In other words, you find cool chicks and hot chicks, but tepid fellows. (And yes, if it gets unseasonably cold, the population will be all female.) © Copyright 2006 Seed Media Group, LLC.

Keyword: Sexual Behavior
Link ID: 9463 - Posted: 06.24.2010

Life is tough for Meloe franciscanus. These blister beetles are born at the base of plants that serve as islands in a sea of sand in the unforgiving Mojave desert. But in order to find food and safe shelter, the larvae, or baby beetles, need to venture out into the scorching desert. To do that, they'll need something to carry them. "The sand temperatures get to 50 degrees centigrade [122 degrees Fahrenheit], which is very hot. You could fry an egg. As a small little larva, they would instantly die if they hit the sand," says Leslie Saul-Gershenz, director of the Center for Ecosystem Survival in San Francisco, adding, "This in the Kelso dunes section of the Mojave desert, so the sand is always moving on the top layer; it can get quite windy." Saul-Gershenz is an ecologist and biologist who wanted to get to the bottom of just now these bugs survive to adulthood. As she found out and reported in Proceedings of the National Academy of Sciences, the blister beetle has evolved an elaborate trick: sibling larvae cooperate to impersonate a female bee both physically and chemically in order to lure a lustful male bee close enough for them to use him like a taxi. © ScienCentral, 2000-2006.

Keyword: Sexual Behavior; Animal Migration
Link ID: 9462 - Posted: 06.24.2010

By Rhitu Chatterjee Pheromones found in a mother's milk may be critical to helping her newborn adjust to its environment. A new study of rabbits shows that pups learn to recognize novel odors only when these odors are associated with a chemical cue that typically signals food and warmth. Learning about the world by sense of smell is common among infants of many mammalian species. Human babies, for example, show interest in whatever foods their mothers eat when nursing because the foods' aromas are passed on through breast milk. Scientists don't understand, however, just how newborn infants learn to identify these additional smells. Neuroethologist Gerard Coureaud of Centre National de la Recherche Scientifique, in Dijon, France, and his colleagues wondered if rabbit pups expand their horizons via the mammary pheromone, a pheromone in rabbit milk known to attract the blind tots to their mums. When the researchers exposed 2-day-old rabbit pups to two new odorants, the pups didn't react to either. But when the team repeated the experiment--this time after first introducing the same two chemicals with the mammary pheromone--the pups immediately started moving towards the source of the smells. Their behavior was identical to the way they search for their mother's nipples, the team reports online 10 October in Current Biology. © 2006 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste); Learning & Memory
Link ID: 9461 - Posted: 06.24.2010

PITTSBURGH -- Young children with autism appear to be delayed in their ability to categorize objects and, in particular, to distinguish between living and nonliving things, according to a breakthrough study by researchers at Children's Hospital of Pittsburgh and Carnegie Mellon University. The paper has been published in the Journal of Developmental and Physical Disabilities and the results could provide a cognitive explanation for one of the characteristics of autism: the inability to recognize the goals and motivations of others. Previous research has shown that young children with autism have the same abilities as normally developing children to categorize objects based on so-called surface characteristics, such as size and shape. They have a diminished ability, however, to group objects into more abstract categories (e.g., birds, trees, cars and furniture). A key characteristic that differentiates living and nonliving things is the ability of the former to move on their own, and as humans, we rely on the motions of others -- a hand reaching out to shake ours, a person running toward us -- to help us interpret their actions and intentions. "People have not really studied these conceptual deficits in very young children as the possible basis for the social and cognitive deficits in older children and adults with autism," said Carnegie Mellon psychologist David Rakison, who co-authored the paper with Cynthia Johnson, director of the Autism Center at Children's Hospital of Pittsburgh and assistant professor of pediatrics and psychiatry at the University of Pittsburgh Medical Center.

Keyword: Autism
Link ID: 9460 - Posted: 10.13.2006

By Tom Jackman As the population in Virginia has grown in recent years, especially in Northern Virginia, the capacity to help the mentally ill has declined steadily. The number of psychiatric beds in Northern Virginia has plummeted from 402 in 1990 to 196 today, and those who can't find treatment often wind up in the court system, either through civil commitment hearings or criminal charges and jail. A recent state study showed that 11 percent of the people in Northern Virginia jails are on psychotropic medications, and many more need mental health services. The study also estimated that about 25 percent of those held on temporary detention orders have no previous connection to the public mental health system. "That tells me two things -- that it's getting harder for people to get the help they need when they're in crisis," said Mary Zdanowicz, executive director of the Treatment Advocacy Center, "and there's a large number of people who are getting no help." Now, Virginia's system of helping the mentally ill is being targeted for reform from a powerful source: the chief justice of the Virginia Supreme Court. Tomorrow, Chief Justice Leroy R. Hassell Sr. is launching a commission to revise Virginia's mental health laws and judicial processes, with five task forces meeting to begin developing recommendations for "reform legislation" that would be presented to the 2008 General Assembly. © 2006 The Washington Post Company

Keyword: Schizophrenia
Link ID: 9459 - Posted: 06.24.2010

By Tony Fitzpatrick -- Teenage boys and computer games go hand-in-hand. Now, a St. Louis-area teenage boy and a computer game have gone hands-off, thanks to a unique experiment conducted by a team of neurosurgeons, neurologists, and engineers at Washington University in St. Louis. The boy, a 14-year-old who suffers from epilepsy, is the first teenager to play a two-dimensional video game, Space Invaders, using only the signals from his brain to make movements. Getting subjects to move objects using only their brains has implications toward someday building biomedical devices that can control artificial limbs, for instance, enabling the disabled to move a prosthetic arm or leg by thinking about it. Many gamers think fondly of Atari's Space Invaders, one of the most popular breakthrough video games of the late '70s. The player controls the motions of a movable laser cannon that moves back and forth across the bottom of the video screen. Row upon row of video aliens march back and forth across the screen, slowly coming down from the top to the bottom of the screen. The objective is to prevent any one of the aliens from landing on the bottom of the screen, which ends the game. The player has an unlimited ammunition supply.

Keyword: Epilepsy
Link ID: 9458 - Posted: 10.11.2006

Early family experience can reverse the effect of a genetic variant linked to depression, UCLA researchers report in the current issue of the journal Biological Psychiatry. Among children from supportive, nurturing families, those with the short form of the serotonin transporter gene (known as 5-HTTLPR) had a significantly reduced risk for depression, found the UCLA team, under the direction of Shelley E. Taylor, UCLA distinguished professor of psychology and an expert in the field of stress and health. The research team also found that among children from emotionally cold, unsupportive homes marked by conflict and anger, those with the short form of the 5-HTTLPR gene were at greater risk for depression, as some previous research has also shown. The 118 young adult men and women who participated in the study completed assessments of depression, early family environment and current stress. They were asked, for example, how often they had been loved and cared for, shown physical affection or insulted and sworn at by their families. Saliva samples were used to determine if the participants' standing on the 5-HTTLPR had two short alleles (s/s), a short and a long allele (s/l) or two long alleles (l/l) for the serotonin transporter gene. (An allele is any of several forms of a gene.) The research showed that a person's likelihood of developing symptoms of depression was not predicted by the particular combination of alleles alone; rather, it was the combination of the person's environment and genetic variant s/s that determined whether the person experienced symptoms of depression, said Taylor, principal investigator on the study.

Keyword: Depression; Genes & Behavior
Link ID: 9457 - Posted: 10.11.2006

Researchers at Boston's Brigham and Women's Hospital announced this week that a laser scan for the eyes has so far been 100 percent accurate as an early detector for Alzheimer's disease in mice. "This is proof-of-concept evidence for early detection. It says that we're on the right track," lead researcher Lee Goldstein says. Goldstein's team used the laser scan eye test to compare mice that were genetically engineered to develop Alzheimer's with normal mice. The laser scan found beta-amyloid protein in the eyes of the Alzheimer's mice well before any evidence was shown in the brain. In Alzheimer's patients the beta-amyloid protein ultimately builds up into plaques between nerve cells in the brain. The laser directs a low-intensity beam of light into the lens of the eye, which bounces off of specific particles, similar to how the sun's light bounces off particles of water in clouds. This produces a "scatter pattern," which scientists use to look for beta-amyloid protein in the eye. According to the National Institute on Aging, Alzheimer's disease affects up to 4.5 million Americans. Alzheimer's patients start to forget loved ones, dates, or how to do simple math. As the disease progresses, Alzheimer's patients can lose the ability to care for themselves and even to speak. © ScienCentral, 2000-2006.

Keyword: Alzheimers
Link ID: 9456 - Posted: 06.24.2010