Matt Kaplan The dawn chorus – when male birds sing their hearts out at sunrise – has puzzled biologists for almost as long as it has inspired poetry. The birds probably do it to show off to females – but is it a signal of strength from being able to sing on an empty stomach, or being tough enough to sing in the cold? Owls, whose activity patterns are the reverse of diurnal birds, could hold the answer, says Loïc Hardouin at the Chizé Centre for Biological Studies, France. Hardouin's team recorded the song of male little owls and measured ambient temperatures over two months. They found that owls spontaneously called much more often just after dusk than later in the night. This is the first time that evidence for a "dusk chorus" has been established, says Hardouin. The birds sang more in the early evening than they did later at night as temperatures got cooler, which suggests that the key message behind the display of toughness is the ability to sing on an empty stomach rather than in the cold, the team says. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Animal Communication
Link ID: 11932 - Posted: 06.24.2010

By Rachel Zelkowitz Weight gain and moodiness top the list of the unpleasant side effects of birth control pills. But could the pill also desensitize a woman's sniffer? New research suggests that oral contraceptives can reduce a woman's ability to smell the best mate. Although birth control can't be blamed for every bad relationship, the findings could help explain how people find their ideal love. Most guys splash on a little cologne before a first date, but past research shows that their natural scent may be the better attractant. Natural odor reflects a person's immune system composition, a collection of genes called the major histocompatibility complex (MHC). In a 1995 study, women sniffed men's shirts and rated the shirts of men with dissimilar MHCs as more appealing than clothes worn by men who had similar MHCs to their own. Having a different MHC--and thus a different genetic profile--from your mate ensures hardier children, the thinking goes, as your offspring inherit the ability to resist a wider range of diseases. The study did find an exception to this rule, however: Women on birth control tended to prefer the shirts of men with MHC profiles similar to their own. To further explore the effect of birth control, Craig Roberts, a biologist at the University of Liverpool in the U.K., and colleagues repeated the T-shirt test with 37 women. Before the women began taking oral contraceptives, they showed no preference between shirts--a finding that conflicted with the 1995 study, the team reports today in the Proceedings of the Royal Society B Biology. After women started taking the pill, however, they marked shirts from men with similar MHCs as more desirable than shirts from men with different MHCs. © 2008 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 11931 - Posted: 06.24.2010

Marlowe Hood -- Meet Gordon, probably the world's first robot to be controlled exclusively by living brain tissue. Stitched together from cultured rat neurons, Gordon's primitive grey matter was designed at the University of Reading by scientists who unveiled the neuron-powered machine on Wednesday. Their groundbreaking experiments explore the vanishing boundary between natural and artificial intelligence, and could shed light on the fundamental building blocks of memory and learning, one of the lead researchers said. "The purpose is to figure out how memories are actually stored in a biological brain," said Kevin Warwick, a professor at the University of Reading and one of the robot's principle architects. Observing how the nerve cells cohere into a network as they fire off electrical impulses, he said, may also help scientists combat neurodegenerative diseases that attack the brain such as Alzheimer's and Parkinson's. "If we can understand some of the basics of what is going on in our little model brain, it could have enormous medical spinoffs," he said. © 2008 Discovery Communications, LLC.

Keyword: Robotics
Link ID: 11930 - Posted: 06.24.2010

People with schizophrenia have an alteration in a pattern of brain electrical activity associated with learning and memory. Now, researchers from the National Institutes of Health and Sweden’s Karolinska Institute have identified in mouse brain tissue a molecular switch that, when thrown, increases the strength of this electrical pattern. The researchers found that adding the brain chemical Neuregulin-1 to the brain tissue boosted the electrical signals that the tissue generated. "This finding may yield new insights into a form of altered brain activity occurring in schizophrenia," said Duane Alexander, M.D., director of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). "It may also lead to new methods for screening drugs with potential as schizophrenia treatments." The findings appear online in the journal Cerebral Cortex. The research was conducted by Andre Fisahn, Ph.D, of the Karolinska Institute, in collaboration with Andres Buonanno, Ph.D, and his colleagues in NICHD’s section on Molecular Neurobiology. Dr. Buonanno was the study’s senior author. Schizophrenia affects about 1.1 percent of the U.S. population. Symptoms include delusions, hallucinations, disordered thinking and social withdrawal. As nerve impulses travel through the brain, they emit weak electrical signals that can be measured through sensors attached to the scalp. The different parts of the brain emit different kinds of electrical signals. These signals vary with the kinds of mental activity taking place within the brain.

Keyword: Schizophrenia
Link ID: 11929 - Posted: 06.24.2010

By Lucy Elkins The human brain: Numerous system which link up and work together The human brain is the most complex organ in the body and contains 20 billion cells, responsible for everything from dreaming and movement to appetite and emotions. It consists mainly of grey matter - the brain cells or neurons where information is processed. It also contains white matter - the nerve fibres which, like electric cables, send out chemical messengers and relay information between the cells. In fact, the brain contains more nerve fibres than there are wires in the entire international telephone network and sometimes the brain's 'wires' can become crossed, as a result of injury, illness or genetics. Scientists used to think a brain injury resulted in permanent damage to the brain's functions, but new research suggests this is not necessarily the case. 'When one area of our brain is damaged we now know from scans that the functions of that area are distributed elsewhere,' says Dr Keith Muir, a senior lecturer in neuroscience at Glasgow University. © 2008 Associated Newspapers Ltd

Keyword: Regeneration; Stroke
Link ID: 11928 - Posted: 06.24.2010

Low levels of the sunshine vitamin, vitamin D, may contribute to chronic pain among women, scientists believe. The link does not apply to men, suggesting hormones may be involved, according to a study published in the Annals of Rheumatic Diseases said. The team from the Institute of Child Health in London said studies were now needed to see if vitamin D supplements can guard against chronic pain. About one in 10 people are affected by chronic pain at any one time in the UK. The causes are not well understood and much of the focus to date has been on emotional factors. Dr Elina Hyppönen and colleagues believe, at least in women, vitamin D levels could play a role in some cases of chronic pain. The nutrient, essential for healthy bones, is produced in the body when exposed to sunlight and is also found in oily fish, egg yolks and margarine. Among the 7,000 men and women aged 45 from across England, Scotland and Wales that they studied, those who were smokers, non-drinkers, the overweight and the underweight all reported higher rates of chronic pain. Among the women, vitamin D levels also appeared to be important. This finding was not explained by gender differences in lifestyle or social factors, such as levels of physical activity and time spent outdoors, say the authors. Women with vitamin D levels between 75 and 99 mmol/litre - a level deemed necessary for bone health - had the lowest rates of this type of pain, at just over 8%. Women with levels of less than 25 mmol/litre had the highest rates, at 14.4%. Severe lack of vitamin D in adults can lead to the painful bone disease osteomalacia. But the researchers said osteomalacia did not account for their findings. (C)BBC

Keyword: Pain & Touch
Link ID: 11927 - Posted: 06.24.2010

By Beth Baker Some aging experts worry that, when it comes to mind games, the marketing has galloped ahead of the science and that consumers and retirement communities may be plunking down hundreds, even thousands, of dollars on products with little evidence to support their claims. The brain-game craze began with the 2005 launch of Nintendo's Brain Age. The video game's latest version challenges you to speed-memorize 25 numbers, beat the computer at rock-paper-scissors and tell time on an upside-down clock. Given recent research suggesting some mind work might maintain or even improve aging brains, gamemakers are hot to bill their products as something more than just entertainment. "Everybody's looking for a computer game," says psychologist Judah Ronch, a professor of practice at the Erickson School of Aging, Management and Policy at the University of Maryland Baltimore County. "Is there any evidence that they're any better [at staving off dementia than exercise or social engagement]? No. But because of the commercial potential, people are beating that horse and hoping it comes in." Last year, revenue for the brain fitness software market reached $225 million, up from $100 million in 2005, according to SharpBrains, a company that tracks the cognitive fitness market. Consumers spent $80 million of that, up from $5 million in 2005; the rest came from school systems, the military, corporations, sports teams, senior facilities and other health organizations. SharpBrains expects the growth to continue. © 2008 The Washington Post Company

Keyword: Alzheimers; Learning & Memory
Link ID: 11926 - Posted: 06.24.2010

By HENRY FOUNTAIN Like many other plants, the chili has a strategy for survival: make its fruit, the pepper, so nutritionally desirable that birds and other creatures will eat it and disperse the seeds. But the same things that make a chili pepper attractive to animals also draw bacteria and funguses that can kill the seeds. It has been thought that the chemicals known as capsaicinoids, which surround the seeds and give peppers their characteristic heat, are the chili’s way of deterring microbes. But if so, then microbial infestation should bring selective pressure on chilis — the more bugs, the hotter the peppers should be. That has never been shown in the wild. Now, however, in a study of wild chili plants, Joshua J. Tewksbury of the University of Washington and colleagues show that the variation in heat reflects the risk that the plants will be attacked by a seed-destroying fungus. The researchers studied a species in Bolivia (where chilis are thought to have originated) that was earlier determined to be polymorphic — some plants produce hot peppers, while identical plants produce fruit that have no heat at all. The new research showed that in populations of the plant across Bolivia, the proportion of hot and not-hot plants varied. Copyright 2008 The New York Times Company

Keyword: Pain & Touch; Chemical Senses (Smell & Taste)
Link ID: 11925 - Posted: 06.24.2010

By Greta Munger and David Munger When most people think of someone who's tone deaf, they're likely to conjure up images of an American Idol contestant who's is shocked when the judges tell her she's got a horrible singing voice—or perhaps the man who belts out every hymn in church but always seems to be at least two notes off from the rest of the congregation. Being tone deaf often doesn't refer just to poor hearing, but also to poor singing. But it's also possible that bad singing isn't actually caused by bad hearing. A recent report by cognitive neuroscientists Peter Q. Pfordresher at the State University of New York at Buffalo and Steven Brown at Simon Fraser University suggests that poor music perception is actually just one of four possible causes of tuneless warbling. Yes, bad hearing might be at fault, but poor control of the vocal system is another possible factor. In other words, even if you can hear the note, you still might not be able to produce it. Third might be an inability to imitate: you can hear the sound and you know what sound you want to produce, but you can't combine the two—just as a baseball player might see a pitch and know how to swing the bat, but still strike out. Fourth, it might be that awful singers have bad memory: between the time they hear a song and when they sing it back, they forget the notes. © 1996-2008 Scientific American Inc.

Keyword: Hearing
Link ID: 11924 - Posted: 06.24.2010

Eric Bland -- A new pill stops the euphoric effects of alcohol, but it won't prevent a hangover the next day. By blocking a key receptor involved in stress, scientists at Oregon Health and Science University are testing a drug that stops the happy feelings brought on by a drink of alcohol. Scientists say the drug could stop not only alcoholics from relapsing, but it could also stop pleasurable feelings gained from cocaine and even food. "This drug has great potential to treat not only alcoholism, but other stress-related disorders as well," said Tamara Phillips, a professor at Oregon Health and Science University and a co-author of the study, which appeared recently in the Proceedings of the National Academy of Sciences. The drug, called CP 154,526, was originally developed and donated for testing by drug giant Pfizer, maker of the popular drug Viagra. CP 154,526 physically binds to a receptor in the brain called corticotrophin-releasing factor one (CRF1). The receptor blocks corticotrophin-releasing factor (CRF), a chemical released by alcohol that is thought to create pleasurable feelings. © 2008 Discovery Communications, LLC

Keyword: Drug Abuse
Link ID: 11923 - Posted: 06.24.2010

Catherine Brahic What is the best asset elephants have for resisting climate change? Possibly their legendarily powerful memory, say conservationists. From 1958 to 1961 a drought killed off dozens of elephants in what is now Tanzania's Tarangire National Park. When another severe dry spell hit the region in 1993, 16 of 81 elephant calves died – a 20% death rate, compared with the usual 2%. Charles Foley of the Wildlife Conservation Society in New York and colleagues wondered if any of the surviving elephants had remembered the previous drought. The researchers looked at how the deaths broke down by sex and clan structure. They found that of three clans, two migrated from the region during the drought, presumably to seek food and water. Their strategy seems to have paid off: the groups that left lost five calves between them, whereas the group that stayed lost 11 of its 27 calves. This could be down to luck, but the team then found that the clan that stayed behind was also the only one to not have any females old enough to have lived through the previous drought. "It is enticing to think that these old females and their memories of previous periods of trauma and survival would have made all the difference," says Foley. "The data seem to support the speculation that the matriarchs with the necessary experience of such events were able to lead their groups to refuge." © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 11922 - Posted: 06.24.2010

By Mark Leyner and Dr. Billy Goldberg What if you could simply swallow a pill and become a buff, shredded, aerobic dynamo all without having to spend one sweaty second in the gym? Wouldn’t an instant fitness drug be great? Maybe not. We were both mighty intrigued to learn that scientists had developed not one, but two “Mighty Mouse Drugs” that endow mice with all the benefits of having worked out furiously, without the effort of actual exercise. Researchers at the Salk Institute in San Diego reported that a drug called Aicar increased mice’s endurance on a treadmill by 44 percent after just four weeks of treatment and helped them burn more calories and have less fat than untreated mice. A second drug with the catchy name “GW1516,” when combined with exercise, boosted the mice’s endurance by a whopping 75 percent! Both drugs activate PPAR-delta protein which produces more high-endurance Type 1 muscle fibers in the body. Aicar actually mimics the effects of exercise, convincing cells that they’ve burned off energy and need to generate more. As one of the researchers said: “It’s pretty much pharmacological exercise.” The researchers contend that it’s reasonable to assume that these results will apply to people. © 2008 Microsoft

Keyword: Obesity
Link ID: 11921 - Posted: 06.24.2010

Variations in a gene may help explain why horror movies shock some people and entertain others, say German scientists. People with one version of the COMT gene startled more dramatically to unpleasant images than others, the researchers found. The work in Behavioural Neuroscience suggest inborn differences make some prone to extreme anxiety and stress. Anxiety treatments could be tailored to fit these genes, the authors suggest. The COMT gene weakens the effect of a signalling chemical (dopamine) in the brain linked to emotion. Dr Martin Reuter and his colleagues at the University of Bonn measured the "startle response" of 96 women with different variations of the gene by attaching electrodes to their eye muscles. When a person is startled upon emotional arousal the eyes automatically blink. The women were shown sets of pictures that were emotionally pleasant (such as animals or babies), neutral (such as an electric plug or hair dryer) or aversive (such as weapons or injured victims at a crime scene). A loud noise was made at random while they watched to startle the volunteers. The women who carried the two copies of the Met158 variation of the COMT gene startled more easily than those carrying two copies of the Val158 variation. The Met158 carries also scored higher on anxiety on standard personality tests. Met158 is found in about half the population but it exerts its effect on the one in four people who have inherited both copies of it from their parents, say the researchers. (C)BBC

Keyword: Emotions; Genes & Behavior
Link ID: 11920 - Posted: 08.11.2008

By Jeffrey Perkel (HealthDay News) -- Researchers have developed a strain of mice resistant to diet-induced obesity. The findings could one day lead to possible drug treatments for obesity in people. They also shed light on the brain circuitry that controls energy homeostasis -- the balance between how much energy (i.e., food) an animal takes in and how quickly it burns that energy. Dr. Julio Licinio, a professor of psychiatry and behavioral sciences at the University of Miami Miller School of Medicine, called the research a "technological tour de force." Dr. Bradford Lowell, associate professor of medicine at Harvard Medical School, led the study, which was published online Aug. 10 in the journal Nature Neuroscience. According to lead study author Qingchun Tong, most research into energy homeostasis has involved what scientists call genetically encoded neuropeptides, rather than small molecule neurotransmitters. Neurotransmitters "have been postulated to play a very important role in neurocommunication, but in this field, essentially no critical studies have been performed to address this issue," Tong said. "So I set up an experiment to create an animal model in which a particular group of neurons in the brain couldn't release a small neurotransmitter, and by examining those animal models, I could know the function of those molecules." © 2008 U.S. News & World Report, L.P.

Keyword: Obesity
Link ID: 11919 - Posted: 06.24.2010

A genetic mutation in dachshunds could help uncover the roots of some inherited forms of blindness in humans, say scientists. Cone-rod dystrophies are caused by progressive cell loss in the retina. Dachshunds are particularly prone to similar conditions, and US and Norwegian researchers spotted an altered gene which may play a role. Writing in the journal Genome Research, they said research on the similar gene in humans might lead to new therapies. Cone-rod dystrophies are relatively rare, and can lead at first to "day-blindness", in which vision in bright light is affected, then to full loss of vision. It can start as early as childhood. Other researchers have already identified genetic variations which seem to contribute to these conditions, but the latest research suggests that its genetic causes could be complex. Inherited vision disorders are more common in dogs, and Dr Frode Lingaas of the Norwegian School of Veterinary Science isolated a particular part of a canine chromosome, and then a particular gene, called NPHP4, a portion of which had been deleted in affected dachshunds. Dr Lingaas said: "This gene has been associated with a combination of kidney and eye disease in human patients. "Here, we found a mutation which affects only the eyes, suggesting this gene might be a candidate for human patients with eye disease only." (C)BBC

Keyword: Vision; Genes & Behavior
Link ID: 11918 - Posted: 08.09.2008

Whether smoking your first cigarette brings on a pleasurable buzz or a wave of nausea may depend on what type of nicotine-related gene you have. Smokers who had one form of a nicotine-receptor gene were eight times as likely to report that their first cigarette gave them a pleasurable buzz, researchers said in Friday's online issue of the journal Addiction. American researchers studied data from 435 volunteers to probe the link between forms of a nicotine-receptor gene called CHRNA5, how people recalled their first smoking experience, and how they smoke now. They compared three groups: those who never smoked; those who never got hooked after trying at least one cigarette but not more than 100; and regular smokers who lit up at least five cigarettes a day for at least five years. Regular smokers were far more likely to have the less common form of the gene compared with those who never smoked, the researchers said. "It appears that for people who have a certain genetic makeup, the initial physical reaction to smoking can play a significant role in determining what happens next," said Ovide Pomerleau, the study's senior author and a professor of psychiatry at the University of Michigan Medical School. © CBC 2008

Keyword: Drug Abuse; Genes & Behavior
Link ID: 11917 - Posted: 06.24.2010

By PETER JARET Insomniacs know all too well what it’s like to lie awake in a tangle of sheets, the day’s worries parading through the brain as the minutes tick past with agonizing slowness. With studies linking troubled sleep to a variety of health problems including heart attacks and obesity, it’s enough to keep anyone awake at night. An estimated 30 million Americans wrestle with chronic insomnia. Many suffer in silence. A 2005 National Sleep Foundation survey found that only one-third of patients with insomnia were asked by their primary care physicians about the quality of their sleep. Insomnia sufferers are equally unlikely to raise the issue with their doctors, studies show. And that’s too bad, experts say. More and safer medications for sleep problems are available. And with a growing list to choose from, doctors can target prescriptions more precisely to specific complaints: trouble falling asleep, for instance, versus trouble staying asleep. Remedies to help people fall asleep have been around for centuries, from laudanum in the 1800s to barbiturates more recently. “Unfortunately, most of them were addictive and potentially deadly,” said Dr. David Neubauer, associate director of the Sleep Disorders Center at Johns Hopkins University School of Medicine in Baltimore. “The history of sleep medications is really a tale of improving safety.” Copyright 2008 The New York Times Company

Keyword: Sleep
Link ID: 11916 - Posted: 06.24.2010

By JANE E. BRODY When Howard D. Schultz in 1985 founded the company that would become the wildly successful Starbucks chain, no financial adviser had to tell him that coffee was America’s leading beverage and caffeine its most widely used drug. The millions of customers who flock to Starbucks to order a double espresso, latte or coffee grande attest daily to his assessment of American passions. Although the company might have overestimated consumer willingness to spend up to $4 for a cup of coffee — it recently announced that it would close hundreds of underperforming stores — scores of imitators that now sell coffee, tea and other products laced with caffeine reflect a society determined to run hard on as little sleep as possible. But as with any product used to excess, consumers often wonder about the health consequences. And researchers readily oblige. Hardly a month goes by without a report that hails coffee, tea or caffeine as healthful or damns them as potential killers. Can all these often contradictory reports be right? Yes. Coffee and tea, after all, are complex mixtures of chemicals, several of which may independently affect health. Through the years, the public has been buffeted by much misguided information about caffeine and its most common source, coffee. In March the Center for Science in the Public Interest published a comprehensive appraisal of scientific reports in its Nutrition Action Healthletter. Its findings and those of other research reports follow. Copyright 2008 The New York Times Company

Keyword: Drug Abuse
Link ID: 11915 - Posted: 06.24.2010

By Lisa Conti The association between darkness and depression is well established. Now a March 25 study in the Proceedings of the National Academy of Sciences reveals for the first time the profound changes that light deprivation causes in the brain. Neuroscientists at the University of Pennsylvania kept rats in the dark for six weeks. The animals not only exhibited depressive behavior but also suffered damage in brain regions known to be underactive in humans during depression. The researchers observed neurons that produce norepi­nephrine, dopamine and serotonin—common neurotransmitters involved in emotion, pleasure and cognition—in the process of dying. This neuronal death, which was accompanied in some areas by compromised synaptic connections, may be the mechanism underlying the darkness-related blues of seasonal affective disorder. Principal investigator Gary Aston-Jones, now at the Medical University of South Carolina, speculates that the dark-induced effects stem from a disruption of the body’s clock. “When the circadian system is not receiving normal light, that in turn might lead to changes in brain systems that regulate mood,” he says. © 1996-2008 Scientific American Inc.

Keyword: Depression; Biological Rhythms
Link ID: 11914 - Posted: 06.24.2010

By Rachel Zelkowitz How much you smell depends on how often you bathe, but precisely how you smell depends on your genes, a new study suggests. The body odors of identical twins are significantly more similar than the scents of unrelated people, researchers in Switzerland have found. The results could pave the way for new tools to diagnose disease or identify people based on scent. Body odor emanates from a chemical reaction between bacteria on the skin and sweat, a secretion that itself is odorless. BO plays a role in mate selection among mice, and some experiments have suggested its importance for human mate selection as well (ScienceNOW, 18 June 2004). Among the most prevalent chemicals in body odor are at least 24 kinds of carboxylic acids. But it wasn't known how much of each of the various acids a person produces, says lead researcher Andreas Natsch, a biochemist for the Givaudan fragrance company in Dübendorf, Switzerland. To test the role of genetics in body odor, Natsch and a colleague recruited 12 pairs of identical twins: seven sets of sisters and five sets of brothers. Because such twins develop from a single fertilized egg, they have identical genes unless a mutation occurs. The researchers gave each pair of twins cotton pads to wear in their armpits while they exercised for about an hour. After the exercise, the researchers collected the pads and treated them with the same bacterial enzyme to ensure that all the sweat samples were processed in a virtually identical fashion. The twins then repeated the process on another day. © 2008 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 11913 - Posted: 06.24.2010