Ewen Callaway A handful of genes could mark the difference between high-strung Chihuahuas and unflappable basset hounds. A comparison of 148 dog breeds has uncovered genes for size, lifespan, and even complex behaviours such as pointing and herding. Geneticists have previously uncovered genes for dog traits such as coat colour and narcolepsy, but these searches tended to focus on a single breed, comparing pooches with variations in a single trait – for example, boxers with and without white spots. This strategy does not work for rooting out the genetic basis of behaviours because certain breeds either display these behaviours or they don't, says Gordon Lark at the University of Utah in Salt Lake City, US. So with the help of a dog show judge, Lark's team scored dogs from 148 breeds for traits including herding, pointing, boldness, excitability and trainability. Then they scoured their genomes for similarities and differences. Dogs were also scored for size, body proportions and longevity. The search implicated several genes in stereotypical dog behaviours. For example, herding behaviour typical of collies and shepherds may be linked to a gene that is similar to one associated with schizophrenia in humans. © Copyright Reed Business Information Ltd.

Keyword: Genes & Behavior; Evolution
Link ID: 11729 - Posted: 06.24.2010

By Tia Ghose In people with autoimmune diseases like multiple sclerosis and asthma, infection-fighting cells go haywire and wage war against the body’s own tissue, causing inflammation. Existing treatments can prevent the immune system from getting out of control, but can also compromise a person’s ability to fight some infections. But a new study suggests that a specific receptor on immune cells holds promise as a target for treating such disorders, perhaps without affecting immunity. The receptor, called DR3, lies on the surface of T cells, which help the body combat infection. When a molecule called TL1A binds to the receptor, it spurs the T cells into action. But this same interaction can also lead the T cells to attack healthy tissue. Turning off the gene for this receptor seems to quell this inflammation in mice, researchers report online June 19 in the journal Immunity. It wasn’t far-fetched to think DR3 may play a role in autoimmune disease. DR3 is part of a family of TNF receptors, which are involved in activating immune cells and have been implicated in autoimmune disease, says Michael Croft, an immunologist at the La Jolla Institute for Allergy and Immunology in California, who was not involved in the study. What’s more, DR3 looks very similar to another receptor implicated in inflammation, says Richard Siegel of the National Institute of Arthritis and Musculoskeletal and Skin Diseases in Bethesda, Md, who was involved in the study. © Society for Science & the Public 2000 - 2008

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 11728 - Posted: 06.24.2010

A herbal extract used by an estimated 10% of people with dementia is not an effective treatment for it, an Imperial College London study suggests. Ginkgo biloba is commonly marketed as an aid to memory and some studies have reported benefits. But a six-month trial of 176 people with mild to moderate dementia found no difference between those taking ginkgo biloba and those taking placebo. The results are in the International Journal of Geriatric Psychiatry. The researchers tested 120 mg daily of ginkgo biloba in patients recruited from London general practices. They measured participants cognitive skills and quality of life at two, four and six months. Tests included exercises such as recalling words from memory or answering questions about time or places. There was no evidence that the standard dose of the herbal extract had any benefit on memory. And quality of life as reported by the patient or by their carer did not improve over the course of the research. A Cochrane review published in 2002 which had taken all relevant evidence into account found ginkgo may be a small beneficial effect on memory in dementia patients. But the researchers say that is being updated in view of this latest research and has found that it is unlikely to provide benefits. Study leader, Dr Rob McCarney who carried out the research at Imperial College London, said the lack of drug treatments in early dementia meant patients would try anything to slow down the progression of the disease. (C)BBC

Keyword: Alzheimers; Learning & Memory
Link ID: 11727 - Posted: 06.19.2008

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