Australian researchers are using new imaging technology to provide an insight into the degenerative effect of Huntington's disease on the brain. Doctoral student India Bohanna, from the Howard Florey Institute in Melbourne, used diffusion magnetic resonance imaging technology to track the breakdown in structural connections within the brain. The research was presented at the Organization for Human Brain Mapping conference being held this week in Melbourne. Bohanna said she and her collaborators at Monash University found extensive white matter degeneration in patients recently diagnosed with Huntington's disease. The researchers used diffusion MRI, which maps the brain's white matter tracts by measuring the movement of water molecules in the tissues. White matter tracts are the connections between brain regions that allow one region to communicate with another. Bohanna said a breakdown in these structural connections disrupts the brain's communication. This could explain the motor and cognitive problems such as memory loss and clumsiness that appear as early symptoms of the onset of Huntington's disease. © Australian Broadcasting Corporation, 2008

Keyword: Huntingtons
Link ID: 11726 - Posted: 06.24.2010

Nicholas Wade, New York Times Intricate as the mating dance may be among people, for other primates like chimpanzees and baboons it is even more complicated. This is evident from the work of researchers who report that the distinctive calls made by female chimpanzees during sex are part of a sophisticated social calculation. Biologists have long been puzzled by these copulation calls, which can betray the caller's whereabouts to predators. To compensate for this hazard, the calls must confer a significant evolutionary advantage, but what? The leading explanation involves the way female primates protect their offspring. Male chimps and baboons are prone to kill any infant they believe could not be theirs, so females try to blur paternity by mating with as many individuals as possible before each conception. A side benefit is that by arranging to have sperm from many potential fathers compete for her egg, the female creates conditions for the healthiest male to father her child. The calls that female chimps make during sex seemed to be just part of this strategy. By advertising a liaison in progress, biologists assumed, females stood to recruit many more partners. But the study, by Simon Townsend, Tobias Deschner and Klaus Zuberbuhler, shows that in making calls or not, the females take the social situation into account. © 2008 Hearst Communications Inc.

Keyword: Sexual Behavior; Language
Link ID: 11725 - Posted: 06.24.2010

By Virginia Morell Like all immigrants, young male songbirds arriving in the United States have to make some quick decisions, beginning with finding the best place to build a nest. A new study reveals that youngsters make their choices after eavesdropping on the songs of their elders. The results add to a growing body of research indicating that birds' songs carry far more social information than scientists realize. Finding the right nesting habitat is key to a songbird's reproductive success, says Matthew Betts, a landscape ecologist at Oregon State University, Corvallis, and the lead author of the study. "Even 50% of experienced males will lose their chicks to predators," he says, so it makes sense for birds to look for places with the most cover. Other studies have shown, however, that songbirds are drawn to areas where they see and hear their fellows nesting. Betts and colleagues suspected that house-hunting young male black-throated blue warblers (Dendroica caerulescens), who arrive in the States from Jamaica, cue in on the songs of their elders. Successful warbler dads sing after their chicks have fledged, most likely to teach their songs to their offspring, says Betts. "But there could be another, unintentional message in their song: 'Hey, I've reproduced,' "--a clue that the older bird is sitting on prime nesting real estate. © 2008 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Language
Link ID: 11724 - Posted: 06.24.2010

By Michael Balter As gay couples race to the altar in California this week, scientists may have found an answer to the so-called gay paradox. Studies suggest that homosexuality is at least partly genetic. And although homosexuals have far fewer children than heterosexuals, so-called gay genes apparently survive in the population. A new study bolsters support for an intriguing idea: These same genes may increase fertility in women. Despite some tantalizing leads over the past 2 decades, researchers have yet to isolate any genes directly linked to homosexuality. Nevertheless, a number of studies have shown that male homosexuals have more gay male relatives on their maternal lines than on their paternal lines, leading some scientists to suggest that gay genes might be found on the X chromosome. And in 2004, a team led by evolutionary psychologist Andrea Camperio Ciani of the University of Padua in Italy reported that women related to gay men had more children than women related to heterosexual men. The differences were striking: The mothers of gay men, for example, had an average of 2.7 children, compared with 2.3 children for the mothers of heterosexual men. A similar trend held for maternal aunts. In new work, reported online this week in PLoS ONE, Camperio Ciani and his colleagues used mathematical modeling to see what kinds of genetic scenarios could explain these results. © 2008 American Association for the Advancement of Science

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 11723 - Posted: 06.24.2010

John Whitfield Why does payday feel good? You can’t eat money, and it can’t have your babies — so how did that 'ker-ching!' feeling become so sweet? Working with rats, neuroscientists have gained an insight into how the brain comes to take pleasure in abstract rewards. Animals, they suggest, have a reward system that focuses on specific outcomes — what an action would achieve — which in turn plugs into a more general system that lets us know what feels good. Understanding how these two systems interact could help us understand what happens when they go wrong, such as in drug addiction or in general failures of willpower. The results are reported in Nature 1. It’s hard to explain why people work for things that are not intrinsically gratifying, says neuroscientist Geoffrey Schoenbaum of the University of Maryland in Baltimore. “People are not normally working for primary rewards, such as food or sex, but for proxies, such as money.” And, he says, they are able to plan their behaviour with distant goals in mind. “You work harder when you want a certain thing, like a new car.” © 2008 Nature Publishing Group

Keyword: Emotions; Drug Abuse
Link ID: 11722 - Posted: 06.24.2010

High levels of the "hunger hormone" ghrelin have an antidepressant effect, US researchers claim. Blocking the body's response to ghrelin has been suggested as a weight loss treatment but it may also produce unintended effects on mood, they said. The Nature Neuroscience study found mice with increased levels of the hormone showed fewer signs of depression and anxiety. Experts said the idea was interesting but further studies were needed. Ghrelin is released by the empty stomach into the bloodstream before moving to the brain, where it triggers feelings of hunger. Treatment with the hormone itself - or a drug designed to cancel its effects - might be able to help both people who are eating too little, such as cancer patients, or those who eat too much, researchers believe. In the latest study, Dr Jeffrey Zigman and colleagues restricted the food intake of laboratory mice for 10 days, causing their ghrelin levels to quadruple. Compared with mice who had free access to food, the calorie-restricted mice showed lower levels of depression and anxiety when subjected to mazes and other behaviour tests. The team also looked at mice genetically engineered to be unable to respond to ghrelin. When they were fed a restricted-calorie diet they did not experience the antidepressant or anti-anxiety effects. The researchers found the same thing when they induced higher ghrelin levels by subjecting the mice to stress. Those mice that could not respond to ghrelin had greater levels of depression-like symptoms than the normal mice. (C)BBC

Keyword: Depression; Obesity
Link ID: 11721 - Posted: 06.17.2008

By TARA PARKER-POPE About 2.5 million children in the United States take stimulant drugs for attention and hyperactivity problems. But concerns about side effects have prompted many parents to look elsewhere: as many as two-thirds of children with attention deficit hyperactivity disorder, or A.D.H.D., have used some form of alternative treatment. The most common strategy involves diet changes, like giving up processed foods, sugars and food additives. About 20 percent of children with the disorder have been given some form of herbal therapy; others have tried supplements like vitamins and fish oil or have used biofeedback, massage and yoga. While some studies of alternative treatments show promise, there is little solid research to guide parents. That is unfortunate, because for some children, prescription drugs aren’t an option. The drugs have been life-changing for many children. But nearly one-third experience worrisome side effects, and a 2001 report in The Canadian Medical Association Journal found that for more than 10 percent, the effects could be severe — including decreased appetite and weight loss, insomnia, abdominal pain and personality changes. Although the drugs are widely viewed as safe, many parents were alarmed when the Food and Drug Administration ordered in 2006 that stimulants like Adderall, Ritalin and Concerta carry warnings of risk for sudden death, heart attacks and hallucinations in some patients. Copyright 2008 The New York Times Company

Keyword: ADHD
Link ID: 11720 - Posted: 06.24.2010

Alison Motluk You don't have to be a scientist to observe that pornographic images lead to erections in men. But you would have to be one to show those images to volunteers while meticulously measuring the volume of response in the brain and penis. Harold Mouras, at University of Picardie Jules Verne in Amiens, France, and his colleagues wanted to understand the cerebral underpinnings of visually-induced erections. They suspected there might be a role for mirror neurons, a special class of brain cell that fires both when people perform an action and when they observe it being performed. The researchers invited eight young men into the lab and asked them to view three types of video clips. Along with late-night fishing documentaries and snippets of Mr Bean, the volunteers got to see erotic videos of men stroking naked women, enjoying fellatio and engaging in intercourse. While the volunteers watched the movies, the researchers watched their brains using functional magnetic resonance imaging (fMRI). They also kept tabs on the tumescence of the other target organ, using a hand-crafted "penile plethysmograph" – essentially an airtight tube in which the enlarging penis causes measurable pressure changes. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 11719 - Posted: 06.24.2010

By Gisela Telis Why do we wrinkle our noses in disgust or widen our eyes with fear? A new study shows that doing so might help keep us alive. The idea that facial expressions confer a survival advantage was first posited, perhaps not surprisingly, by Charles Darwin. In 1872, 13 years after he published On the Origin of Species, Darwin wrote a lesser-known tome, The Expression of the Emotions in Man and Animals. In it, he observed that some human expressions occur across cultures and even in some other animals. He cited the wide-eyed gasp of surprise as an example. Darwin speculated that these emotional faces might serve a biological function, such as getting a good look at an enemy. Darwin's hypothesis went untested until 3 years ago, when cognitive neuroscientist Adam Anderson, graduate student Joshua Susskind, and their colleagues at the University of Toronto in Canada decided to apply new technology to the century-old idea. The researchers computer-generated a "classic" fear face: one with raised brows, popping eyes and flaring nostrils. They also mocked up a disgust face: the wrinkled nose, raised lip, and narrowed eyes familiar to anyone who's smelled rotten eggs or stepped in something foul. The team then asked volunteers to mimic these faces while taking vision and breathing tests. Emotional faces weren't just for looks. The team found that a fearful visage improves peripheral vision, speeds up eye movement, and boosts air flow, potentially allowing a person to more quickly sense and respond to danger. Squinty, scrunched-up disgusted faces had the opposite effect, limiting vision and decreasing air flow, ostensibly to keep out substances that might be harmful to the eyes or lungs. © 2008 American Association for the Advancement of Science.

Keyword: Emotions
Link ID: 11718 - Posted: 06.24.2010

The brains of gay men and women look like those found in straight people of the opposite sex, research suggests. The Swedish study, published in the Proceedings of the National Academy of Sciences journal, compared the size of the brain's halves in 90 adults. Gay men and heterosexual women had halves of a similar size, while the right side was bigger in lesbian women and heterosexual men. A UK scientist said this was evidence sexual preference was set in the womb. Scientists have noticed for some time that homosexual people of both sexes have differences in certain cognitive abilities, suggesting there may be subtle differences in their brain structure. This is the first time, however, that scientists have used brain scanners to try to look for the source of those differences. A group of 90 healthy gay and heterosexual adults, men and women, were scanned by the Karolinska Institute scientists to measure the volume of both sides, or hemispheres, of their brain. When these results were collected, it was found that lesbian women and heterosexual men shared a particular "asymmetry" in their hemisphere size, while heterosexual women and gay men had no difference between the size of the different halves of their brain. In other words, structurally, at least, gay men were more like heterosexual women, and gay women more like heterosexual men. A further experiment found that in one particular area of the brain, the amygdala, there were other significant differences. In heterosexual men and lesbian women, there were more nerve "connections" in the right side of the amygdala, compared with the left. The reverse, with more neural connections in the left amygdala, was the case in homosexual men and heterosexual women.

Keyword: Sexual Behavior; Brain imaging
Link ID: 11717 - Posted: 06.17.2008

Hearing loss is about twice as common in adults with diabetes compared to those who do not have the disease, according to a new study funded by the National Institutes of Health (NIH). "Hearing loss may be an under-recognized complication of diabetes. As diabetes becomes more common, the disease may become a more significant contributor to hearing loss," said senior author Catherine Cowie, Ph.D., of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), who suggested that people with diabetes should consider having their hearing tested. "Our study found a strong and consistent link between hearing impairment and diabetes using a number of different outcomes." The researchers discovered the higher rate of hearing loss in those with diabetes after analyzing the results of hearing tests given to a nationally representative sample of adults in the United States. The test measured participants’ ability to hear low, middle, and high frequency sounds in both ears. The link between diabetes and hearing loss was evident across all frequencies, with a stronger association in the high frequency range. Mild or greater hearing impairment of low- or mid-frequency sounds in the worse ear was about 21 percent in 399 adults with diabetes compared to about 9 percent in 4,741 adults without diabetes. For high frequency sounds, mild or greater hearing impairment in the worse ear was 54 percent in those with diabetes compared to 32 percent in those who did not have the disease. Adults with pre-diabetes, whose blood glucose is higher than normal but not high enough for a diabetes diagnosis, had a 30 percent higher rate of hearing loss compared to those with normal blood sugar tested after an overnight fast.

Keyword: Hearing; Obesity
Link ID: 11716 - Posted: 06.24.2010

(HealthDay News) -- People with sleep apnea show tissue loss in brain regions that help store memory, a University of California, Los Angeles (UCLA) study shows. "Our findings demonstrate that impaired breathing during sleep can lead to serious brain injury that disrupts memory and thinking," principal investigator Ronald Harper, a professor of neurobiology at the David Geffen School of Medicine at UCLA, said in a prepared statement. People with sleep apnea stop breathing and awaken repeatedly during the night, leading to chronic daytime fatigue and memory and concentration problems. Research has linked sleep apnea to an increased risk of stroke, heart disease and diabetes. In this study, the UCLA team used MRI to scan the brains of sleep apnea patients. The researchers focused on brain structures called mammillary bodies, located on the underside of the brain. The study found that the mammillary bodies of the 43 sleep apnea patients were almost 20 percent smaller than those in 66 people without sleep apnea. The results will be published in the June 27 issue of Neuroscience Letters. © 2008 U.S. News & World Report

Keyword: Sleep; Learning & Memory
Link ID: 11715 - Posted: 06.24.2010

Researchers may have found a way to predict whether severely brain-damaged patients will regain consciousness. A part of the brain which can stay active even in severely brain-damaged patients could offer a clue about the chances of recovery, they claim. The Belgian team told a conference that activity within a "default network" in the brain appears to match the level of consciousness of the patient. Some believe the default network is associated with daydreaming. The findings were reported in New Scientist magazine. The default network in the brain's cortex appears to be more active when the brain is not actively working on a goal - hence the proposed link with daydreaming. Some evidence suggests that it helps get the brain ready for the next task, although this remains a controversial theory. A number of techniques are used to assess the level of consciousness in people following head injury, and while some are diagnosed as "brain dead", with no sign of any activity in the brain, it can be difficult to make an exact diagnosis when the patient has a higher level of activity, but is still unconscious. Dr Steven Laureys, from the University of Liege in Belgium, believes that activity within the network could help confirm the level of consciousness, and help doctors decide on whether or not to treat them. He measured activity in 13 brain-injured patients with a variety of different levels of consciousness. Some were "minimally conscious", while others were in a coma, or a persistent vegetative state (PVS). A final group were "brain dead". He found that minimally conscious patients had only a 10% fall in normal activity in this area, while in coma and PVS patients, it fell by approximately 35%. There was no activity at all in the brain-dead patients. (C)BBC

Keyword: Stroke; Brain Injury/Concussion
Link ID: 11714 - Posted: 06.14.2008

By DAMIEN CAVE MIAMI — From “Scarface” to “Miami Vice,” Florida’s drug problem has been portrayed as the story of a single narcotic: cocaine. But for Floridians, prescription drugs are increasingly a far more lethal habit. An analysis of autopsies in 2007 released this week by the Florida Medical Examiners Commission found that the rate of deaths caused by prescription drugs was three times the rate of deaths caused by all illicit drugs combined. Law enforcement officials said that the shift toward prescription-drug abuse, which began here about eight years ago, showed no sign of letting up and that the state must do more to control it. “You have health care providers involved, you have doctor shoppers, and then there are crimes like robbing drug shipments,” said Jeff Beasley, a drug intelligence inspector for the Florida Department of Law Enforcement, which co-sponsored the study. “There is a multitude of ways to get these drugs, and that’s what makes things complicated.” The report’s findings track with similar studies by the federal Drug Enforcement Administration, which has found that roughly seven million Americans are abusing prescription drugs. If accurate, that would be an increase of 80 percent in six years and more than the total abusing cocaine, heroin, hallucinogens, Ecstasy and inhalants. Copyright 2008 The New York Times Company

Keyword: Drug Abuse
Link ID: 11713 - Posted: 06.24.2010

By BENEDICT CAREY The people who suffer from schizophrenia are hardly the only ones confounded by its symptoms. Scientists are baffled, too, and despite years of study they’ve had little success in explaining how the disorder develops, in whom, and why. Yet there’s a restless energy among psychiatric researchers now, and it’s in part because of several recent studies that, paradoxically, reveal how insufficient current theories about schizophrenia are. Schizophrenia is not a single problem with a uniform solution, these results suggest. Rather, the disease most likely comprises a variety of related mental disorders, with an underlying biology and symptoms that can differ from person to person. That shift in thinking has already led to expanded treatment options for some patients, and it is likely to guide research on the disorder for years to come. Perhaps the most striking demonstration of how biologically diverse schizophrenia may be came in a gene study published in March. An analysis of blood samples revealed that rare and previously undetectable genetic mutations were strongly associated with the development of the disorder. Copyright 2008 The New York Times Company

Keyword: Schizophrenia
Link ID: 11712 - Posted: 06.24.2010

By Trisha Gura A recent tabloid captured the common wisdom about anorexia nervosa. In an interview, actor Christina Ricci blamed the pressures of success for her prior struggle with the disease. The headline flashed, “Ricci: Hollywood made me anorexic.” But did it? True, anorexia is characterized by compulsive dieting or exercise to get thin. And the pursuit of thinness in contemporary culture—particularly in Hollywood—has become a seemingly contagious obsession. Yet there is thin, and then there is emaciated. Crossing over that line means a loss of a basic survival instinct—to eat in response to hunger—that culture should not be able to touch. What is more, cultural cues cannot easily explain why the afflicted, who are shockingly skinny, misperceive themselves as fat. Anorexics also say they feel more energetic and alert when starving: starvation boosts their metabolic rate, which is in stark contrast to the slowing of metabolism that occurs in most people during a fast. Such mysteries cry out for a biological explanation. To find one, researchers are probing the brains of anorexics; their work is painting a new picture of anorexia as a multifaceted mental illness whose effects extend far beyond appetite. The illness is accompanied by disturbances in the brain’s reward circuitry that may lead to a general inability to feel delight from life’s pleasures, be they food, sex or winning the lottery. As such, the ailment shares characteristics with drug addiction—the drug in this case being deprivation itself. © 1996-2008 Scientific American Inc

Keyword: Anorexia & Bulimia
Link ID: 11711 - Posted: 06.24.2010

Anrica Deb -- A Dutch woman who was the oldest person in the world when she died at age 115 in 2005 appeared sharp right up to the end, joking that pickled herring was the secret to her longevity. Scientists say that Henrikje van Andel-Schipper's mind was probably as good as it seemed: a post-mortem analysis of her brain revealed few signs of Alzheimer's or other diseases commonly associated with a decline in mental ability in old age. That came as something of a surprise, said Gert Holstege, a professor at Groningen University, whose findings will be published in the August edition of Neurobiology of Aging. "Everybody was thinking that when you have a brain over 100 years, you have a lot of problems," he said in a telephone interview on Friday. He cited a common hardening of arteries and the build up of proteins associated with Alzheimer's disease as examples. "This is the first (extremely old) brain that did not have these problems." Van Andel was the oldest living person in the world at the time of her death in 2005 in the Dutch city of Hoogeveen, according to the Guinness Book of World Records. © 2008 Discovery Communications, LLC

Keyword: Alzheimers; Development of the Brain
Link ID: 11710 - Posted: 06.24.2010

Alison Abbott Zurich's two largest institutes are appealing to the country's supreme court after a lower court decided to ban two primate experiments studying how the brain adapts to change. They say that the ban is a serious threat to all basic research that uses animals in Switzerland. The University of Zurich and the Federal Institute of Technology Zurich (ETHZ) announced on 4 June that their local administrative court had ruled against the experiments on rhesus monkeys that had been approved in 2006 by the Swiss National Science Foundation, a funding agency and the Zurich canton's veterinary office, which is responsible for controlling animal welfare. The veterinary office decision was challenged by an external advisory committee on animal experimentation, which argued that the proposed experiments would offend the dignity of the animals. The requirement to consider the 'dignity of creatures' was introduced into the Swiss constitution in 2004. The court did not refer to dignity, but agreed that society was unlikely to see the benefits of the research during the three-year funding period approved, and thus the burden on the animals was not justified. Swiss law requires that the benefit to society must be weighed against the burden to animals before any animal experiment can take place. © 2008 Nature Publishing Group

Keyword: Animal Rights
Link ID: 11709 - Posted: 06.24.2010

Dementia could be slowed significantly by treatments which reset the body's natural clock, researchers have said. The Dutch team used brighter daytime lighting - with or without the drug melatonin - to improve patients' sleep, mood and cut aggressive behaviour. It concludes that these can slow deterioration by 5% - which a UK specialist said meant patients living in their own homes for months longer. The study appears in the Journal of the American Medical Association. The disruption to the body's circadian rhythm - the natural cycle that governs sleep and wakefulness - can be one of the most difficult of dementia symptoms for carers to cope with. It can mean that people with the illness can be asleep during the day, but fully awake for periods during the night. Other studies have suggested that the use of bright room lighting and melatonin can help adjust the "clock", and the researchers from the Royal Netherlands Academy of Arts and Sciences in Amsterdam managed to recruit 189 care home residents to take part in an unique trial. Six of the care homes taking part had lighting installed, and this was turned on between 9am and 6pm every day. Some of the patients, most of whom had some form of dementia, received melatonin, a naturally-occurring hormone, and their progress was then monitored for at least the next year. Those who had melatonin, but no extra lighting, had better sleep patterns, but tended to be more withdrawn and have a worse mood. However, patients having melatonin and bright light together managed to avoid these mood problems. (C)BBC

Keyword: Alzheimers; Biological Rhythms
Link ID: 11708 - Posted: 06.12.2008

By Caroline Zink People are incredibly social beings, and we rely heavily on our interactions with others to thrive, and even survive, in the world. To avoid chaos in these interactions, humans create social norms. These rules and regulations establish appropriate and acceptable ways for us to act and respond to each other. For instance, when waiting in line, we expect people also to wait their turn. As a result, we get upset when someone decides to cut in line: they violated a social norm. But how are social norms maintained? And what makes us comply with social norms? Primarily, the answer is that, if we don’t follow the rules, we might get in trouble. Numerous studies demonstrate that, when the threat of punishment is removed, people tend to disregard social norms. The neat and orderly line disintegrates. It remains unclear, however, how the brain processes the threat of punishment when deciding whether or not to comply with a social norm. A recent study conducted by neuroscientist Manfred Spitzer and his colleagues at the University of Ulm in Germany and the University of Zurich in Switzerland tried to shed light on this mystery. The researchers put 24 healthy male students in a functional magnetic resonance imaging (fMRI) scanner to see what parts of the brain were activated during a two-person social exchange with real monetary stakes. © 1996-2008 Scientific American Inc.

Keyword: Emotions
Link ID: 11707 - Posted: 06.24.2010