Costly methadone treatment for heroin addicts could be replaced by a substitute painkiller that is half the price, safer and less toxic. In a study spanning three and a half years, researchers found that the prescription painkiller dihydrocodeine is equally as effective as methadone to help drug users kick the habit. The research by the Universities of Edinburgh, Napier and Adelaide could have major implications for treatment programmes for drug users, which have proved controversial not least because of the high costs involved. In contrast to methadone –which comes in liquid not tablet form – dihydrocodeine is much easier to store and comes under less stringent regulations because it is not as toxic and less likely to cause a fatal overdose. It is estimated that whereas methadone treatment can cost almost £1,500 annually per patient, the cost of dihydrocodeine is £713. Dihydrocodeine has been used by GPs and specialists for many years to treat drug users . It is often preferred in situations where methadone is seen as hazardous, such as police custody or prison. Its effectiveness has, however, never been tested before. Dr Roy Robertson, a Reader at the University of Edinburgh, who is the study’s main author, said: "Heroin addiction is a chronic condition requiring long-term medication. Just as with other chronic conditions, such as diabetes or arthritis, there should be a number of treatments available so that doctors and nurses can tailor medication to the needs of each patient.

Keyword: Drug Abuse
Link ID: 9716 - Posted: 06.24.2010

Philip Ball A controversial theory of how we smell, which claims that our fine sense of odour depends on quantum mechanics, has been given the thumbs up by a team of physicists. Calculations by researchers at University College London (UCL) show that the idea that we smell odour molecules by sensing their molecular vibrations makes sense in terms of the physics involved1. That's still some way from proving that the theory, proposed in the mid-1990s by biophysicist Luca Turin2, is correct. But it should make other scientists take the idea more seriously. "This is a big step forward," says Turin, who has now set up his own perfume company Flexitral in Virginia. He says that since he published his theory, "it has been ignored rather than criticized." Most scientists have assumed that our sense of smell depends on receptors in the nose detecting the shape of incoming molecules, which triggers a signal to the brain. This molecular 'lock and key' process is thought to lie behind a wide range of the body's detection systems: it is how some parts of the immune system recognise invaders, for example, and how the tongue recognizes some tastes. But Turin argued that smell doesn't seem to fit this picture very well. Molecules that look almost identical can smell very different — such as alcohols, which smell like spirits, and thiols, which smell like rotten eggs. And molecules with very different structures can smell similar. ©2006 Nature Publishing Group

Keyword: Chemical Senses (Smell & Taste)
Link ID: 9715 - Posted: 06.24.2010

Richard Fisher Humans may have evolved altruistic traits as a result of a cultural “tax” we paid to each other early in our evolution, a new study suggests. The research also changes what we knew about the genetic makeup of our hunter-gatherer ancestors. The origin of human altruism has puzzled evolutionary biologists for many years (see Survival of the nicest). In every society, humans make personal sacrifices for others with no expectation that it will be reciprocated. For example, we donate to charity, or care for the sick and disabled. This trait is extremely rare in the natural world, unless there is a family relationship or later reciprocation. One theory to explain how human altruism evolved involves the way we interacted as groups early in our evolution. Towards the end of the Pleistocene period – about 12,000 years ago – humans foraged for food as hunter-gatherers. These groups competed against each other for survival. Under these conditions, altruism towards other group-members would improve the overall fitness of the group. If an individual defended the group but was killed, any genes that the individual shared with the overall group would still be passed on. © Copyright Reed Business Information Ltd

Keyword: Evolution
Link ID: 9714 - Posted: 06.24.2010

Brain scans could help predict schizophrenia, research suggests. Magnetic resonance imaging (MRI) scans have revealed key changes in the brain's grey matter in a small group before they developed symptoms. The finding suggests tracking these changes over time, combined with traditional assessments, could help doctors to predict illness. The research, published in BioMed Central Medicine, was carried out by the University of Edinburgh. For ten years, scientists followed 200 young people who were at a high risk of developing schizophrenia because two or more members of their family had already been diagnosed with the illness. They analysed MRI scans of 65 of the 200 young people, taken on average 18 months apart. The researchers looked specifically for changes in grey matter - brain tissue made principally of neurones which transmit messages and help to store memories. Eight of the 65 went on to develop schizophrenia on average 2.3 years after their first scan. The MRI scans of each of these eight individuals revealed that they had changes in grey matter that happened before they became unwell. Specifically, they showed a reduction in grey matter in a part of their brain called the inferior temporal gyrus, which is linked to the processing of anxiety. People who develop schizophrenia are known often to exhibit signs of raised anxiety levels up to two years before the onset of full psychosis. As members of a high risk group, each person in the study had approximately a 13% risk of developing schizophrenia. However, the specific changes to the grey matter pinpointed by the researchers raised the risk to 60%. (C)BBC

Keyword: Schizophrenia; Brain imaging
Link ID: 9713 - Posted: 12.07.2006

Left-handed people can think quicker when carrying out tasks such as playing computer games or playing sport, say Australian researchers. Connections between the left and right hand sides or hemispheres of the brain are faster in left-handed people, a study in Neuropsychology shows. The fast transfer of information in the brain makes left-handers more efficient when dealing with multiple stimuli. Experts said left-handers tended to use both sides of the brain more easily. Study leader Dr Nick Cherbuin from the Australian National University measured transfer time between the two sides of the brain by measuring reaction times to white dots flashed to the left and right of a fixed cross. He then compared this with how good participants were at carrying out a task to spot matching letters in the left and right visual fields, which would require them to use both sides of the brain at the same time. Tests in 80 right-handed volunteers showed there was a strong correlation between how quickly information was transferred across the left and right hemispheres and how quickly people spotted matching letters. But when the tests were repeated in 20 left-handed volunteers, the researchers found that the more left-handed people were, the better they were at processing information across the two sides of the brain. Extreme left-handed individuals were 43 milliseconds faster at spotting matching letters across the right and left visual fields than right-handed people. Dr Cherbuin, research fellow at the University concluded: "These findings confirm our prediction of increasing efficiency of hemispheric interactions with increasing left-handedness." But he added that it wasn't a clear-cut pattern as there were subtle differences between strongly and mildly left-handed or right-handed individuals. (C)BBC

Keyword: Laterality
Link ID: 9712 - Posted: 12.07.2006

By HAROLD McGEE LAST week I went to Stanford University to hear a lecture on the molecular biology of smell, and then drove home buzzing with thoughts about what it might mean for people who love to eat. The speaker, the Nobel laureate Linda Buck, never mentioned food. She gave an overview of the fast-developing understanding of smell, including the pioneering work for which she shared the Nobel in Physiology or Medicine in 2004. Along the way she explained how, given what is known about the way smells are represented in the brain, the combination of two aromatic substances could create a third smell sensation that would be unlike the smell of either of the partners. And she presented evidence that certain aromatic chemicals — amines, which are found in the bodies of all animals and also in a variety of foods — trigger a brain circuit of their own. They act as pheromones in other animals, and may do the same in humans. I came away filled with new ideas about the alchemy of cooking. Can one flavor plus one flavor equal three flavors? How much of the effect of combining ingredients happens on the stove, and how much in people’s heads? Are there examples of this kind of virtual ingredient creation in familiar dishes? Can a rational awareness of flavor chemistry and amine circuitry influence and heighten our actual sensory experience of food? If we know more about how we smell, can we smell more? Does more sensation mean more pleasure? Copyright 2006 The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 9711 - Posted: 06.24.2010

(BETHESDA, MD) -- Intense itching and the urge to scratch are symptoms of many chronic skin ailments. A new study conducted by Oxford University researchers has found that different reactions in the brain to two common allergy triggers -- allergens (pollen and dust) and histamine (allergy cells within the body caused by foods, drugs or infection) -- may shed some light on the itch-scratch cycle. The study is entitled Itch and Motivation to Scratch: An Investigation of the Central and Peripheral Correlates of Allergen- and Histamine-Induced Itch in Humans. The research team was comprised of Siri G. Leknes, Susanna Bantick, Richard G. Wise and Irene Tracey, all of the Department of Physiology, Anatomy and Genetics, Oxford University, Oxford, UK and Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Clinical Neurology, Oxford University, Oxford, UK; and Carolyn M. Willis and John D. Wilkinson, both of the Department of Dermatology, Amersham Hospital, Amersham, UK. The results of the study are published in the online edition of the Journal of Neurophysiology (http://jn.physiology.org/). The journal is one of the 14 scientific publications published by the American Physiological Society (APS) (www.The-APS.org) every month. Twenty eight female volunteers were recruited for the study, of which 14 tested positive (atopic cohort) for type I allergens (grass pollen and/or house dust mite) and 14 did not (non-atopic cohort). Over three consecutive days the atopic cohort was challenged with either their specific allergen or histamine, along with the saline control group, by applying a skin prick to the forearm. Non-atopic subjects were challenged with histamine and saline on two consecutive days.

Keyword: Pain & Touch
Link ID: 9710 - Posted: 12.07.2006

Researchers have found evidence for a fundamental molecular mechanism underlying the hyperactive high of cocaine. In studies with rats, they have traced the effect to interactions between two types of receiving stations in neurons for nerve signals from their neighbors. The researchers' studies in rats found that when the animals received cocaine, a component of a receptor for the neurotransmitter dopamine tends to grab onto a component of a receptor for glutamate. The result, they found, was interference with normal activation of this glutamate receptor. John Wang, of the University of Missouri, Kansas City School of Medicine, and his colleagues published their findings in the December 7, 2006, issue of the journal Neuron, published by Cell Press. Neurons trigger nerve impulses in their neighbors by launching bursts of chemicals called neurotransmitters at them. The neurotransmitters activate protein receptors on the receiving neurons, which induce the nerve impulses in the receiving cell. These receptors also adjust themselves in complex ways to alter the sensitivity of the receiving neuron to stimulation. Researchers had long known that cocaine affects both dopamine and glutamate receptors on neurons, but the molecular details of those effects were unknown. In their experiments, Wang and colleagues first determined that cocaine reduces the activation of glutamate-responsive neurons by affecting a specific component, or subunit, of the receptor, called NR2B.

Keyword: Drug Abuse
Link ID: 9709 - Posted: 12.07.2006

Jennifer Viegas, Discovery News — What do dog barks have in common with bird tweets and human baby cries? All appear to communicate basic emotions, such as fear, aggression and submission, in somewhat the same acoustic way, according to a new Applied Animal Behavior Science study that suggests a primitive communication system may unite virtually all mammals. The theory could help explain why previous research has found that many mammals, including humans, understand the vocalizations of different species. For example, a Language Communication study determined young children can identify simple emotions conveyed in macaque calls. Another study, published in Primate Cognition, indicated that an African grey parrot could communicate with a bonobo. For the recent research, Péter Pongrácz and colleagues studied how well people with varying dog experience could describe the emotional content of several artificially assembled bark sequences. The barks, which were based on sounds made by a Mudi (a Hungarian herding dog), covered five emotional states: aggressiveness, fear, despair, playfulness and happiness. Pongrácz, a professor of ethology at Eötvös Loránd University in Budapest, Hungary, and his team found that even people with little prior dog experience could correctly match the bark sequences with the previously determined emotional intent of the original barks. © 2006 Discovery Communications Inc.

Keyword: Language; Animal Communication
Link ID: 9708 - Posted: 06.24.2010

Narelle Towie Bats have a novel device for guiding them home on starless nights. In addition to their well-known sensory talents, it seems that big brown bats can tune into the Earth's magnetic field, using it as a compass to guide them to roost. This ability comes in handy on long-distance flights, where their usual mode of navigation — bouncing sounds waves off objects using ultrasound — doesn't do much good. Richard Holland from Princeton University, New Jersey, and colleagues looked at 15 North American big brown bats (Eptesicus fuscus), which travel up to 100 kilometres to find hibernation sites for the winter. To first test the animals' natural navigational abilities, they attached small radio transmitters to the bats and transported them 20 kilometres from their roost. One by one they let them go, and tracked them from a small aircraft. All of them headed directly back to their roost. How did they do this? Researchers have previously suggested that bats might use the direction of the sunset to set their compass. Others have found traces of magnetic materials within bats, suggesting that they might use the planet's magnetic fields to find north. ©2006 Nature Publishing Group

Keyword: Animal Migration
Link ID: 9707 - Posted: 06.24.2010

Peter Aldhous It is a brain map like no other, has been three years in the making, and promises a revolution in neuroscience: a genomic atlas of the mouse brain has been crafted. Unveiled in its full glory today, the Allen Brain Atlas contains 85 million images, and enough data to fill 20,000 iPods. It documents the activity of more than 21,000 genes across the entire mouse brain in such fine detail that it is possible pick out individual cells. Already, the atlas has revealed that the mammalian brain contains “hidden” structures, defined by common patterns of gene activity. “It is a profound enabling tool that is going to dramatically facilitate and accelerate research,” says Marc Tessier-Lavigne, senior vice-president of the biotech firm Genentech in South San Francisco, US. “By having all of the information collated in one place, you can do all of the searching that would not otherwise be possible.” Ed Lein and colleagues at the Allen Institute Brain Science in Seattle, US, created the atlas using a technique called "in situ hybridisation". This involves bathing thin slices of brain tissue in chemically labelled RNA probes that bind to sequences, called messenger RNA, produced by individual genes. The process had to be repeated for each gene, and for slices of tissue taken from different parts of the brain, to build a 3D map of gene activity that can be navigated using software available on the web. © Copyright Reed Business Information Ltd

Keyword: Genes & Behavior; Development of the Brain
Link ID: 9706 - Posted: 06.24.2010

By Pallab Ghosh A UK company is applying for permission to transplant stem cells made from human foetal tissue into the brains of stroke patients. Guildford-based ReNeuron has told the BBC it has convincing lab evidence that the cells could potentially regenerate brain cells damaged by a stroke. It has applied to the US Food and Drug Administration to carry out human trials on 12 stroke patients. However, opponents have said it is a "sick proposal". The ReNeuron team have successfully extracted stem cells from the developing brain area of a 12 week old aborted foetus. These cells have begun to specialise into brain cells and have the ability to rapidly generate brain tissue. According to Dr Eric Miljan, Reneuron's head of stem cell discovery, when the foetal stem cells were injected into the brains of rats in which a stroke had been induced their movement recovered. Tests showed that blood flow and brain activity were restored in the damaged area. Dr Miljan said: "We're very excited. There have been a battery of tests. There have been a series of animal safety experiments. And they work." The company is to submit its research results to the FDA, and if the human trial is approved it could begin early next year. But the regulators will want to be satisfied that the trials will be safe and hold out a realistic chance of doing some good. In particular they will want to look closely at a crucial part of the treatment which involves genetically modifying the foetal brain cells. (C)BBC

Keyword: Stroke; Stem Cells
Link ID: 9705 - Posted: 12.06.2006

By BENEDICT CAREY In a long-awaited analysis, health officials reported yesterday that antidepressant medications appeared to increase significantly the risk of suicide attempts and related behaviors in adults under 25, while reducing such risks in older people. The analysis, the most comprehensive and rigorous to date, found that suicidal behavior of any kind was rare, and that people taking the medications were no more likely to kill themselves than those taking placebo pills. But adults under 25 taking the drugs were more than twice as likely as those on placebos to report a suicide attempt, or to prepare for one by, say, writing a suicide note. The report, which included more than a dozen medications, was compiled by the Food and Drug Administration and posted on its Web site. The findings are the latest chapter in a yearslong debate that has recently focused on children and adolescents. In 2004, after doing a similar analysis, the F.D.A. required drug makers to include on their labels prominent warnings that the drugs were associated with an increased risk of suicidal thinking and behavior in minors. The new study is likely to shift the same attention to young adults, experts said, and may encourage patient advocates who believe that antidepressants like Prozac have hidden dangers, and psychiatrists who insist that the medications are safe. Dr. Kelly Posner, an assistant professor of child psychiatry at Columbia, who helped the F.D.A. analyze the data, said the findings should be treated with caution, because the drug trials studied were not designed to evaluate suicide risk. Copyright 2006 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 9704 - Posted: 12.06.2006

(PHILADELPHIA) -- Of the five senses, taste is one of the least understood, but now researchers at the University of Pennsylvania School of Medicine have come one step closer to understanding how the sense of taste develops. They have pinpointed a molecular pathway that regulates the development of taste buds. Using genetically engineered mice, they discovered that a signaling pathway activated by small proteins called Wnts is required for initiating taste-bud formation. They have also determined that Wnt proteins are required for hooking up the wiring of taste signals to the brain. Senior author Sarah E. Millar, PhD, Associate Professor in the Departments of Dermatology and Cell and Developmental Biology, Penn postdoctoral fellow Fei Liu, PhD, and colleagues report their findings in the most recent online issue of Nature Genetics. "The developmental biology of taste is underexplored," says Millar of her team's impetus for the study. The researchers demonstrated that blocking the action of Wnt proteins in surface cells of the developing tongue prevents taste-bud formation, while stimulating Wnt activity causes the formation of excessive numbers of enlarged taste papillae that are able to attract taste-related nerve fibers. This study represents the first genetic analysis of taste-organ initiation in mammals. While these studies were performed in mice, the researchers believe that their findings will also hold true for understanding the basis of taste-bud development in humans.

Keyword: Chemical Senses (Smell & Taste); Development of the Brain
Link ID: 9703 - Posted: 12.06.2006

When faced with a depressed patient, clinicians often have to choose a proper course of treatment based on a guess as to which neurotransmitter in the brain is being disrupted--serotonin, noradrenaline or both. According to Jan Melichar, a psychiatrist at the University of Bristol, doctors "get it right about 60 to 80 percent of the time," but they have to wait up to one month to see if they chose correctly. A report appearing in the December 6 issue of The Journal of Neuroscience could result in an easier way of putting patients on a path to mental stability. The authors, coauthored by Melichar and Lucy Donaldson, a neuroscientist and physiologist also at the University of Bristol, found that a person's sense of taste--known to be genetic and once thought to be fixed--is in fact plastic and responds to changes in neurotransmitter levels as well as to different moods. The research group gave 20 volunteers either one of two classes of common antidepressants--serotonin specific reuptake inhibitors (SSRIs) or noradrenaline reuptake inhibitors (NARIs)--or a placebo. (Each drug increases the level of its specific neurotransmitter in the brain.) Before taking the treatments and then again two hours after, the subjects took taste tests where researchers gave them solutions of tastants in different concentrations and told them what taste to expect: sour, salt, sweet or bitter. The participants then had to indicate at what concentration they could detect taste. The team discovered that those who took SSRIs reported an increased sensitivity to sweet and bitter tastes, detecting them at concentrations of 27 percent and 53 percent lower, respectively, than before ingestion of the drug. © 1996-2006 Scientific American, Inc.

Keyword: Depression; Chemical Senses (Smell & Taste)
Link ID: 9702 - Posted: 06.24.2010

If I can’t remember this morning where I put my car keys last night, it’s due to my memory failing me again. Scientists at the Max Planck Institute for Medical Research in Heidelberg have been investigating how memories might be consolidated. Their new study offers the hitherto strongest proof that new information is transferred between the hippocampus, the short term memory area, and the cerebral cortex during sleep. According to their findings and contrary to previous assumptions, the cerebral cortex actively controls this transfer. The researchers developed a new technique for their investigations which promises previously impossible insight into the largely under-researched field of information processing in the brain (Nature Neuroscience, November 2006). The question of how the brain stores or discards memories still remains largely unexplained. Many brain researchers regard the consolidation theory as the best approach so far. This states that fresh impressions are first stored as short-term memories in the hippocampus. They are then said to move within hours or a few days - usually during deep sleep - into the cerebral cortex where they enter long-term memory. Investigations by Thomas Hahn, Mayank Mehta and the Nobel Prize winner Bert Sakmann from the Max Planck Institute for Medical Research in Heidelberg have now shed new light on the mechanisms that create memory. According to their findings, the areas of the brain work together, but possibly in a different way from that previously assumed. "This is a technically sophisticated study which could have considerable influence on our understanding of how nerve cells interact during sleep consolidation," confirmed Edvard Moser, Director of the Centre for the Biology of Memory in Trondheim, Norway.

Keyword: Learning & Memory; Sleep
Link ID: 9701 - Posted: 06.24.2010

Narelle Towie The more severe the social dysfunction of an autistic patient, the smaller the part of their brain that governs fear-response, according to a new study. The results have scientists wondering whether some of the symptoms of severe autism are due to the brain becoming so overworked that it attacks its own cells. The amygdala — a small part of the brain that governs emotional responses, such as fear — is thought to be important in autism, as it helps to govern social behaviour. To examine the relationship, Richard Davidson and his team at the University of Wisconsin in Madison, decided to try and match amygdala size to the development of autism. They took MRI scans of 28 male autistic participants ranging in age from 8 to 25 years, and calculated the volume of their amygdala. The researchers then looked at whether the patients tended to avoid eye contact — a well-known symptom of autism. Eye-tracking equipment was used to watch how the participants reacted when looking at images of emotional faces: autistic children tend to avoid the eyes in such pictures, and are slower at distinguishing facial expressions. They then compared the extent of eye-contact avoidance and the particpant's age with the size of their amygdala. The results showed that the most severely affected, older subjects had the smallest fear centres in their brain. ©2006 Nature Publishing Group

Keyword: Autism; Emotions
Link ID: 9700 - Posted: 06.24.2010

Catherine Brahic Some animals stand to gain from warming climates, say researchers who have looked at the effect of changing rainfall on mating and sexual selection in grey seals in Scotland. Sean Twiss, at Durham University, UK, and his colleagues studied the grey seals that mate at the North Rona colony in Scotland. They found that the reduction in freshwater pools in dry years forced females to wander away from their usual breeding spots, and the watchful eye of their dominant male. This allowed a greater number of previously unsuccessful males to copulate with them, and decreased the dominant males' access to females. The result is an increase in genetic diversity in these populations of grey seals. Every year, from September to mid-November, heavily pregnant females return to North Rona for 18 days. During this time, they give birth to a pup. Then, on about day 16, they mate, before setting off to sea again. The females each have preferred spots, gathered around pools of rainwater which keep them cool and supplied in drinking water. This clustering makes it easy for dominant, polygamous males to keep an eye on their 10 to 15 females and mate with them when they are ready. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 9699 - Posted: 06.24.2010

By JANE E. BRODY It is that time of year again, when despite the ratcheting up of festivities for the holidays, fully one person in five in the United States ratchets down. The cause is a now well-known but still infrequently treated disorder, winter blues or SAD, for seasonal affective disorder. There are several remedies to help those affected by SAD escape an affliction that leaves many wanting to climb into bed, put their heads under the covers and not come out until spring. Indeed, some experts refer to SAD as a form of hibernation. The problem typically starts gradually as the days become shorter in late summer or fall and peaks in midwinter in regions where there may be just 9 or 10 hours of daylight, if that. For the estimated 14 million severely affected American adults, SAD can send them into a tailspin that makes it difficult if not impossible to fulfill daily responsibilities and derive any joy from life. An additional 33 million people are less severely affected but may experience declines in energy, cheerfulness, creativity or productivity in the dark days of winter. The most commonly used treatment is exposure for up to several hours a day to high-intensity artificial light, in an effort to simulate the longer days of summer when people with SAD function at top speed. Copyright 2006 The New York Times Company

Keyword: Biological Rhythms; Depression
Link ID: 9698 - Posted: 12.05.2006

Jennifer Viegas, Discovery News — Whales do it. Chickens do too. And now chimpanzees can be added to the list of animals that appear to produce distinctive word-like calls for specific things, according to a study in this month’s Animal Behavior. If such vocalizations indicate what’s on the animals’ minds, then for zoo chimps it’s bananas, mangos and bread. Researchers Katie Slocombe and Klaus Zuberbühler discovered that captive chimps likely create referential, vocal labels for these particularly coveted foods. "Our analyses surprisingly showed that grunts to banana, bread and mango were acoustically distinct," Zuberbühler, a researcher in the School of Psychology at the University of St. Andrews in Scotland, told Discovery News. "It is very possible, therefore, that recipients can use this information to draw inferences about the type of food encountered by the caller." The scientists studied 11 chimpanzees at the Edinburgh Zoo, as well as a community of chimps in the wild at the Budongo Forest Reserve, Uganda. For each group, the researchers first identified the chimps' favorite foods. For the zoo animals, the scientists were even able to determine their medium-preferred foods (grapes, plums and chow) and their least faves among food regularly offered (apples, greens and carrots). The wild chimps seemed to feed most often on certain trees, including a type of uncultivated fig tree. © 2006 Discovery Communications Inc.

Keyword: Language; Evolution
Link ID: 9697 - Posted: 06.24.2010