When scientists developed an efficient device for emitting light, they hadn't realised butterflies have been using the same method for 30 million years. Flourescent patches on the wings of African swallowtail butterflies work in a very similar way to high emission light emitting diodes (LEDs). These high emission LEDs are an efficient variation on the diodes used in computer displays and TV screens. The University of Exeter, UK, research appears in the journal Science. In 2001, Alexei Erchak and colleagues at the Massachusetts Institute of Technology (MIT) demonstrated a method for building a more efficient LED. Most light emitted from standard LEDs cannot escape, resulting in what scientists call a low extraction efficiency of light. The LED developed at MIT used a two-dimensional (2D) photonic crystal - a triangular lattice of holes etched into the LED's upper cladding layer - to enhance the extraction of light. And layered structures called Bragg reflectors were used to control the emission direction. These high emission devices potentially offer a huge step up in performance over standard types. Pete Vukusic and Ian Hooper at Exeter have now shown that swallowtail butterflies evolved an identical method for signalling to each other in the wild. (C)BBC

Keyword: Evolution; Vision
Link ID: 8195 - Posted: 11.18.2005

By BENEDICT CAREY Scientists working with mice have found that by removing a single gene they can turn normally cautious animals into daring ones, mice that are more willing to explore unknown territory and less intimidated by sights and sounds that they have learned can be dangerous. The surprising discovery, being reported today in the journal Cell, opens a new window on how fear works in the brain, experts said. Gene therapy to create daredevil warriors is likely to remain the province of screenwriters, but the new findings may help researchers design novel drugs to treat a wide array of conditions, from disabling anxiety in social settings to the sudden flights of poisoned memory that can persist in the wake of a disaster, an attack or the horror of combat. The discovery may well prove applicable to humans, the experts said, because the brain system that registers fear is similar in all mammals. Moreover, the genetic change did not appear to affect the animals' development in other ways. "Potential clinical applications could be quite important" for people with "fear-related mental disorders," said Dr. Gleb Shumyatsky, an assistant professor of genetics at Rutgers, who led a team that included investigators from Columbia, Harvard, the Howard Hughes Medical Institute and the Albert Einstein College of Medicine. Copyright 2005 The New York Times Company

Keyword: Emotions; Genes & Behavior
Link ID: 8194 - Posted: 11.18.2005

By Susan Brown WASHINGTON, D.C.--Some parents play Mozart for their infants, hoping to instill genius, or at least give them a leg up when they start school. While the strategy has been discounted as a path toward early achievement, musicians may have an edge over nonmusicians when distinguishing between speech sounds. The results may help explain how music therapy sometimes aids children struggling with language and reading. Listening to people speak is more complicated than it might seem. The brain must make out the individual sounds--called phonemes--that make up words. The critical contrasts can be slight: The acoustic difference between the syllables "ba" and "da," for instance, lasts only 40 milliseconds. Trouble with these distinctions may make reading difficult for dyslexic children. But studies have shown that singing and rhythm games improve dyslexic children's spelling and phonological skills. That led Nadine Gaab of the Massachusetts Institute of Technology in Cambridge to wonder whether music somehow enhances a student's ability to discriminate rapid changes within sound. She and colleagues looked for the answer by rounding up 14 adult musicians who had learned to play an instrument before they were 7 years old and who continued to play at least a few hours each week. They then pitted the speech discrimination abilities of these performers against 14 nonmusicians matched in age, gender, and general language ability. © 2005 American Association for the Advancement of Science.

Keyword: Hearing; Language
Link ID: 8193 - Posted: 06.24.2010

A Scots-led medical research team has identified a new gene linked to major mental illness that links back to a previously discovered gene known to increase the risk of schizophrenia and depression. Scientists from the Universities of Edinburgh and Glasgow, together with scientists from the pharmaceutical company Merck, Sharp & Dohme Limited, report the discovery of the second gene, phosphodiesterase 4B (PDE4B) in the prestigious journal Science today (17 November). Their discoveries could lead to the eventual development of new drugs to treat mental health problems. In 2000, researchers at the University of Edinburgh identified a gene they called Disrupted in Schizophrenia 1 (DISC1), which was found to increase the chances of people developing schizophrenia, bipolar disorder (manic depression) and major clinical depression. Now, new research by the two Universities and by scientists from the pharmaceutical company Merck Sharpe and Dohme reveals that damage to the gene PDE4B is also seen to increase the risk of developing mental illness. PDE4B was already known to play an important role in how the brain thinks and builds memories, but had not previously been linked to mental disorder. In addition, researchers have discovered that DISC1 acts as a regulator for PDE4B, creating a 'pathway' between the two genes.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 8192 - Posted: 11.18.2005

Jim Giles reports back from the annual brain science jamboree, from 12-16 November in Washington DC. Day 3: Space anxieties Rats exposed to cosmic rays are more reluctant to enter open areas, such as parts of a maze without shelter. This implies that they're more anxious, just like their older counterparts. If astronauts ever go on trip to other planets, they will be exposed to cosmic rays. So NASA should be careful, as the astronauts could act old and anxious too. This seemed like a logical step too far to me, so I put my scepticism to the researchers from University of Maryland, Baltimore County on whose poster these results appeared. It turns out not to be so unreasonable. The work is the latest in a line of studies in which rats have been exposed to simulated cosmic rays from a particle accelerator at Brookhaven National Laboratory. The fact that these studies managed to justify the $10,000 an hour that it costs to run the accelerator indicates just how badly NASA wants them done. In each study the rats have been given behavioural tasks designed assess things like their desire for novelty. And in each case the cosmic rays have caused younger rats to perform more like older animals. In the maze study, old rats tend to be anxious and therefore wary of entering exposed areas. The rays seem to turn wild young rats into stay-at-home oldies. Day 2: Model of mind - in a rat? Day 2: Rejected by Science Day 1: Popularity contest Day 1: Not so ecstatic ©2005 Nature Publishing Group

Keyword: Emotions
Link ID: 8191 - Posted: 06.24.2010

Deactivating a specific gene transforms meek mice into daredevils, researchers have found. The team believe the research might one day enable people suffering from fear – in the form of phobias or anxiety disorders, for example – to be clinically treated. The research found that mice lacking an active gene for the protein stathmin are not only more courageous, but are also slower to learn fear responses to pain-associated stimuli, says geneticist Gleb Shumyatsky, at Rutgers University in New Jersey, US. In the experiments, the stathmin-lacking mice wandered out into the centre of an open box, in defiance of the normal mouse instinct to hide along the box’s walls to avoid potential predators. And to test learned fear, the mice were exposed to a loud sound followed by a brief electric shock from the floor below them. A day later, normal mice froze when the sound was played again. Stathmin-lacking mice barely reacted to the sound at all. In both mice and humans, the amygdala area of the brain serves as the control centre of basic fear impulses. Stathmin is found almost exclusively in this and related brain areas. © Copyright Reed Business Information Ltd.

Keyword: Emotions; Genes & Behavior
Link ID: 8190 - Posted: 06.24.2010

COLUMBUS, Ohio– An experience as simple as watching graphically violent or emotional scenes in a movie can induce enough stress to interfere with problem-solving abilities, new research at Ohio State University Medical Center suggests. A related study suggests a beta-blocker medication could promote the ability to think flexibly under stressful conditions, neurology researchers say. The research, presented Wednesday (11/16) at the annual Society for Neuroscience meeting in Washington, D.C., represents the first time scientists have asked participants to combine movie viewing with problem-solving tasks to assess the effects of stress on cognitive flexibility, said David Beversdorf, a neurologist at OSU Medical Center and senior author of the studies. The researchers juxtaposed two very different movies – "Saving Private Ryan" and "Shrek" – to induce stress or set up a control condition before testing participants for verbal mental flexibility. "Performance on the tests was significantly impaired after the 'Saving Private Ryan' clip as compared to after the 'Shrek' clip," Beversdorf said. "Therefore, 'real-world' types of stressors can significantly impair the ability to think flexibly." The research has implications for understanding the range of effects of stress on thinking and could have broader clinical implications for patients with anxiety disorders or substance abuse problems, Beversdorf said.

Keyword: Stress; Learning & Memory
Link ID: 8189 - Posted: 06.24.2010

It sounds like science fiction: simply swallowing a pill, or eating a specific food supplement, could permanently change your behaviour for the better, or reverse diseases such as schizophrenia, Huntingtons or cancer. Yet such treatments are looking increasingly plausible. In the latest development, normal rats have been made to behave differently just by injecting them with a specific amino acid. The change to their behaviour was permanent. The amino acid altered the way the rat's genes were expressed, raising the idea that drugs or dietary supplements might permanently halt the genetic effects that predispose people to mental or physical illness. It is not yet clear whether such interventions could work in humans. But there is good reason to believe they could, as evidence mounts that a range of simple nutrients might have such effects. Two years ago, researchers led by Randy Jirtle of Duke University Medical Center in Durham, North Carolina, showed that the activity of a mouse's genes can be influenced by food supplements eaten by its mother just prior to, or during, very early pregnancy (New Scientist, 9 August 2003, p 14). Then last year, Moshe Szyf, Michael Meaney and colleagues at McGill University in Montreal, Canada, showed that mothers could influence the way a rat's genes are expressed after it has been born. If a rat is not licked, groomed and nursed enough by its mother, chemical tags known as methyl groups are added to the DNA of a particular gene.

Keyword: Miscellaneous
Link ID: 8188 - Posted: 11.17.2005

GAINESVILLE, Fla. - Researchers with the University of Florida and the California Institute of Technology have developed a new strain of genetically modified mice that allow scientists to examine the potential usefulness of new therapies for Alzheimer's disease. The development, reported Nov. 15 in the international open-access medical journal PloS Medicine, has helped scientists evaluate the brain's ability to repair one of Alzheimer's hallmark lesions, senile plaque. These plaques occur when enzymes - proteins that cause or speed up chemical reactions - create peptide fragments called beta amyloid, also known as Abeta. The fragments clump together to form senile plaques, clogging the spaces between cells and damaging parts of the brain used for memory and decision-making. The mice were genetically engineered by scientists to respond to a type of therapy designed to lower production of Abeta by inhibiting the enzymes responsible for peptide release. "We can stop the disease from getting worse in these mice, but we can't reverse it," said David Borchelt, Ph.D., a professor of neuroscience at the McKnight Brain Institute of the University of Florida. "Although it is possible that human brains repair damage better than mouse brains, the study suggests that it may be difficult to repair lesions once they've formed."

Keyword: Alzheimers
Link ID: 8187 - Posted: 11.17.2005

Excessive computer gaming has the hallmarks of addiction, suggests new experiments on "drug memory". The researchers argue it should be classified as such, enabling “addicts” to start seeking help. “We have the patients and we have the parents and family members calling us for help,” says Sabine Grüsser of the Charité University Medicine Berlin, in Germany. Learning is recognised as an important underlying mechanism of addiction. In becoming addicted, people start to associate cues that are normally neutral with the object of their craving. To a crack addict, for instance, a building in which they have used the drug is more than just a place they have been – it becomes a trigger for craving and can, on its own, reignite a need to use the drug again after months of abstinence. Grüsser and her colleague Ralf Thalemann wanted to see if computer game cues could also trigger similar “drug memories” in excessive computer gamers. They compared 15 men in their 20s who admitted that gaming had chased other activities – such as work and socialising – out of their lives, and 15 game-playing but otherwise healthy controls. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 8186 - Posted: 06.24.2010

ATHENS, Ohio – There’s hope for the less-than-perfect male – if you’re a swordtail fish, that is. As the size and age of female swordtail fish increase, so does the preference for males with asymmetrical markings, according to a new Ohio University study. Molly Morris, associate professor of biological sciences, and colleagues found that older female swordtails spent more time with asymmetrically striped males than symmetrical males when offered a choice. These findings are the first to contradict previous studies showing that females tend to prefer males with symmetrical markings, which in this case are black bars on each side of the body. Scientists have suggested that symmetrical markings are a sign of genetic fitness. The new study provides evidence that visual cues are not the only thing driving mate selection, however. The findings also suggest that “females may not have the same mating preferences throughout their lives,” Morris said. Funded by the National Science Foundation and the Research Challenge Program at Ohio University, the paper has been published online in Biology Letters and will appear in next month’s print edition. © 2005 Ohio University

Keyword: Sexual Behavior; Evolution
Link ID: 8185 - Posted: 06.24.2010

By CHARLES McGRATH The case files of mental illness are filled with half-baked theories and their drastic advocates. Wilhelm Fleiss, for example, believed that sexual hang-ups stemmed from irregularities in the nasal cavity and that a little judicious snipping could set everything straight. In 1895 he famously botched an operation on Sigmund Freud's patient Emma Eckstein, absent-mindedly leaving a yard of surgical gauze stuffed in her head and almost causing her to bleed to death. Dr. Walter J. Freeman, a central figure in "My Lobotomy," a radio documentary that will be broadcast this afternoon on the National Public Radio program "All Things Considered," believed that the source of many mental disturbances was the thalamus, in which overabundant emotions tended to congregate. The solution, in his view, was simply to sever that part of the brain from the frontal lobes. In the late 1930's, Dr. Freeman was one of the first Americans to perform a transorbital lobotomy, in which holes are drilled in the patient's head. In 1946 he devised a faster and more efficient procedure, the prefrontal, or "ice pick," lobotomy, in which a spike is driven beneath the lids of both eyes and then swirled around in a sort of eggbeater motion to scramble the neural connections. He had some positive results, as in the case of Ann Krubsack, who today says she believes that the operation greatly helped her schizophrenia, if not entirely curing it, and enabled her to raise a family and hold down a job she liked. Copyright 2005 The New York Times Compan

Keyword: Depression; Schizophrenia
Link ID: 8184 - Posted: 11.16.2005

Rats, like humans, love sugar. So it comes as no surprise that during two weeks of training for a recent lab experiment, the rodents queued up twice daily for small doses of sugar water. What researchers did not anticipate was the apparent effect of the sweet stuff on their stress levels: when they placed the rats in stressful circumstances at the end of those two weeks, the animals were less agitated than expected. Multiple blood samples taken from these rats showed lower levels of stress hormones known as glucocorticoids than those that were given a saccharin solution or just plain water before being subjected to psychological or physical duress, according to research presented yesterday at the annual meeting of the Society for Neuroscience in Washington, D.C. "We actually found that sugar snacks, not artificially sweetened snacks, are better self-medications for the two most common types of stress--psychological and physical," explains Yvonne Ulrich-Lai, a postdoctoral fellow in psychiatry at the University of Cincinnati who led the study. Stressful events trigger the hypothalamus region of the brain, which links up with the pituitary and adrenal glands in what has been dubbed the "stress axis" to produce glucocorticoids. These stress hormones help the body defend itself under difficult conditions. But, when present in excessive quantities or for too long, they have been linked to a weakened immune system and increased abdominal fat, among other undesirable effects. © 1996-2005 Scientific American, Inc.

Keyword: Stress; Obesity
Link ID: 8183 - Posted: 06.24.2010

COLUMBUS , Ohio – A new study suggests that hamsters may suffer from symptoms of anxiety and depression during the dark days of winter, just as some humans do. Using a variety of tests, researchers found more symptoms of depression and anxiety in adult hamsters that were housed for weeks in conditions with limited daylight, as they would find in winter, when compared to hamsters who had days with longer daylight. The research also examined whether hamsters that developed prenatally and then were born during short days were more likely to suffer from depression and anxiety as adults. The results for these tests were mixed, but suggest that hamsters born in winter-like light conditions had increased depressive symptoms as adults. Overall, the results suggest that the season the hamsters were born in, their sex, and the changing of the seasons all may play a role in levels of depression and anxiety. “These results in hamsters may provide some insight into the development of seasonal affective disorders in humans,” said Randy Nelson, co-author of the study and professor of psychology and neuroscience at Ohio State University. Nelson conducted the study with Leah Pyter, a doctoral student in neuroscience at Ohio State . They presented their results Nov. 15 in Washington , D.C. at the annual meeting of the Society for Neuroscience.

Keyword: Depression; Biological Rhythms
Link ID: 8182 - Posted: 06.24.2010

By Larry O'Hanlon, Discovery News — They might be your best friends, but just what makes Fido and Fifi tick is far from well understood, said researchers who have surveyed seven decades of dog personality studies. Despite a surge in canine temperament studies since the 1960s, there are some large holes in the research, said University of Texas at Austin psychologists who are hoping to fill some of the voids. For instance, the vast majority of dog studies have been on young German shepherds and Labrador retrievers. As a result, practically nothing is scientifically known about the personality differences of pit bulls and poodles, or even whether personality traits are truly breed-specific. "There aren't tried and true assessments of dog temperaments," said psychologist Amanda Jones. Jones and her colleague Samuel Gosling evaluated 51 canine studies from the 1930s to the present. Their results are published in the November issue of Applied Animal Behavior Science. © 2005 Discovery Communications Inc.

Keyword: Emotions; Evolution
Link ID: 8181 - Posted: 06.24.2010

Jim Giles Brain researchers are developing tests that can identify the beginnings of Alzheimer's years before the first clinical signs of the disease emerge. The researchers, who presented their results on 14 November at the annual meeting of the Society for Neuroscience in Washington DC, say the tests allowed them to single out people who went on to develop the condition. If those results are repeated using larger study groups, doctors could start using the tests straight away. One test uses brain scans to spot the first hints of problems that will later cause dementia. William Jagust of the University of California, Berkeley, and his group tracked about 60 healthy old people for around three years, using two brain-imaging techniques and exercises designed to probe memory and cognition. Six of the group developed forms of dementia and several others started to suffer from the cognitive impairments that precede full-blown Alzheimer's. When Jagust looked back at the scans taken at the start of the project, he found that several brain areas showed tell-tale signs in these subjects. Neural activity in temporal and parietal lobes, for example, was below average in people that later scored poorly in cognitive tests. ©2005 Nature Publishing Group

Keyword: Alzheimers
Link ID: 8180 - Posted: 06.24.2010

STANFORD, Calif. - When the U.S. Food and Drug Administration declared in 2004 that certain antidepressants are linked to an increased risk of suicide in adolescents, there was surprisingly little data about how depression was being treated in young patients. Now new research from the Stanford University School of Medicine provides critical documentation of the potential misuse of these medications in the years leading up to the FDA's decision to issue the so-called "black-box" warnings. The researchers found that, despite clinical guidelines calling for depressed adolescents to be treated with a combination of psychotherapy and medication, antidepressants began supplanting - rather than complementing - the role of mental health counseling between 1995 and 2002. And although only one antidepressant has been sanctioned for use in children, the study found that doctors were prescribing a variety of mood-altering medications for young patients. The researchers hope their findings provide a benchmark for assessing how the 2004 decision affects depression treatment in children, while reinforcing that antidepressants can be a valuable treatment tool if used appropriately. "We're not saying that doctors should avoid prescribing antidepressants for kids, but we are pointing out the potential for inappropriate use of antidepressants," said Jun Ma, MD, PhD, research associate at the Stanford Prevention Research Center and lead author of the study that will appear in the December issue of the Journal of Adolescent Health. "If used as part of a comprehensive treatment regimen, antidepressants are of great benefit to individual patients and to the society as a whole."

Keyword: Depression; Drug Abuse
Link ID: 8179 - Posted: 11.16.2005

Multiple sclerosis patients are to be able to get a cannabis-based pain-relief drug on the NHS for the first time, it has been announced. Sativex has already been licensed for use in Canada to relieve pain in people with MS. The Home Office has now said the drug can be imported to the UK for individual patient's use. MS charities welcomed the development as a step towards the drug being fully licensed for use on the NHS. Eighty-five thousand people in the UK have MS. It is not yet certain how many of them would benefit from Sativex. The drug is a mouth spray containing two chemicals found in cannabis, tetrahydrocannabinol and cannabidiol. The announcement is believed to be in response to enquiries to the Home Office from doctors and patients about access to the drug. Under the new arrangements, the prescription of Sativex would only be permitted under Home Office licence. Sativex can significantly reduce nerve pain in MS patients, a study has shown. Researchers at Liverpool's Walton Centre for Neurology and Neurosurgery compared the drug with a dummy version in a study of 66 patients.Dr Carolyn Young, who led the research which was published in the journal Neurology, said the drug was seen to reduce pain and sleep disturbance. A doctor would have to take responsibility for the prescription of the unlicensed drug, which would have to be imported from Canada for that particular patient. The government has asked a watchdog, the Commission on Human Medicines, to monitor the safety of Sativex. (C)BBC

Keyword: Multiple Sclerosis
Link ID: 8178 - Posted: 11.15.2005

By MARY DUENWALD When is it a good idea for an adolescent to take a sleeping pill? There is reason to suppose the answer may be never. No prescription sleep aids are approved by the Food and Drug Administration for use in people under 18, largely because they have not been well studied in children. But children do take sleeping pills. In 2004, more than 180,000 people under age 20 in the United States - most of them 10 or older took sleep medications, according to estimates released last month by Medco Health Solutions, a large managed-care company. Although that represents only about one child in 500, Medco found that usage was up by 85 percent since 2000. The numbers reported by Medco were somewhat mysterious: the company's report did not indicate why the pills were prescribed for the patients under 18, or which pills were prescribed for them. That makes some doctors worry that the large increase may reflect a certain amount of unnecessary prescribing. To some extent, not sleeping enough is a normal part of adolescence. Copyright 2005 The New York Times Company

Keyword: Sleep
Link ID: 8177 - Posted: 11.15.2005

By CONNIE ROGERS People keep asking Carel van Schaik if there is anything left to discover in fieldwork. "I tell them, 'A lot,' " said Dr. van Schaik, the Dutch primatologist. "Look at gorillas. We've been studying them for decades, and we just now have discovered that they use tools. The same is true for orangutans." JUST LOOKING An adult male orangutan went about his business in the swamps of Sumatra under the watchful gaze of the Dutch primatologist Carel van Schaik. In 1992, when Dr. van Schaik began his research in Suaq, a swamp forest in northern Sumatra, orangutans were believed to be the only great ape that lived a largely solitary life foraging for hard-to-find fruit thinly distributed over a large area. Researchers thought they were slow-moving creatures - some even called them boring - that didn't have time to do much but eat. But the orangutans Dr. van Schaik found in Suaq turned all that on its head. More than 100 were gathered together doing things the researchers had never seen in the wild. Copyright 2005 The New York Times Company

Keyword: Evolution
Link ID: 8176 - Posted: 11.15.2005