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

By Tina Hesman Saey As open-and-shut cases go, Alzheimer’s disease should top the list. The victim is clear. Suspects are in custody. Wherever neurons die due to Alzheimer’s disease, a protein known as amyloid-beta is always found at the scene of the crime, hanging around in large, tough gangs called plaques. Parkinson’s and Huntington’s diseases; amyotrophic lateral sclerosis (which goes by its initials ALS or the alias Lou Gehrig’s disease); and prion diseases, such as scrapie in sheep, mad cow disease in cattle and Creutzfeldt-Jakob disease in humans, all have similar stories. Scientific investigators have pieced together this much: A seemingly mild-mannered brain protein falls in with a bad crowd, the corrupted protein and its cronies gang up and mob violence results in the death of a brain cell. It’s a scene repeated over and over again in different neighborhoods of the brain, by different proteins, but all with the same result — the death of neurons and rise of disease. But no one has convicted these suspected neuron killers. So far, cases mostly rely on circumstantial evidence, with large holes in the web of proof. There’s no smoking gun, no motive and no eyewitness to corroborate what scientists suspect. And there’s no cure for the diseases that slowly break down brains and spinal cords, robbing victims of memories or mobility. © Society for Science & the Public 2000 - 2008

Keyword: Alzheimers; Huntingtons
Link ID: 11912 - Posted: 06.24.2010

Jo Carlowe In 477BC the Greek poet Simonides of Ceos devised a memory technique called the “method of loci”. This entails memorising items along an imagined journey and then mentally retracing one's steps to recall each article. More than 2,000 years later, the same mnemonic system will be brought into play at the UK Open Memory Championships next weekend in London. Over two days, competitors from across the country will face gruelling mental challenges, from memorising a sequence of 200 random words in five minutes, to remembering the sequence of playing cards in as many decks as possible. The winner will compete at the World Memory Championships in Bahrain in October. The open nature of the UK competition is something of a misnomer. As Phil Chambers, “chief arbiter” of the championship, explains, anyone untrained in the art of “mind sports” can expect humiliation. To put it into perspective: on average most of us can recall between five and nine numbers in a row. The eight-times world memory champion Dominic O'Brien, 50, can remember the order of 54 randomly shuffled decks of playing cards - an astounding 2,808 cards. He has turned his memory into a full-time career, running memory workshops and writing numerous books. Copyright 2008 Times Newspapers Ltd.

Keyword: Learning & Memory
Link ID: 11911 - Posted: 06.24.2010

For many people, our only experience with Parkinson’s disease is that of watching actor Michael J. Fox struggle publicly with the illness as he has campaigned for more research and funding. But as my colleague Karen Barrow notes in the latest “Patient Voices” feature, there are many less-famous faces of Parkinson’s. Parkinson’s disease is a neurologic disorder that occurs as a result of the death of nerve cells in the brain that produce dopamine. The loss of dopamine production in the brain can lead to tremors, balance problems, stiff facial expressions and muffled speech, among other things. In the United States, an estimated 1 million people have the disease, and another 60,000 are diagnosed each year. Although the condition usually develops after the age of 60, 15 percent of those diagnosed are under 50. One of those is runner Alyssa Johnson, 43, who was training for the Boston Marathon in 2003 when she started dragging her leg and developed a shin cramp. After searching for answers, she was finally diagnosed with Parkinson’s. “It’s not something you’d expect with someone my age,'’ she said. “I used to run with my husband all the time. We don’t run together anymore because it’s still too hard for me emotionally. He’s still competitive, and I’m still trying to get from point A to point B.'’ Copyright 2008 The New York Times Company

Keyword: Parkinsons
Link ID: 11910 - Posted: 06.24.2010

US scientists have discovered people who can "hear" what they see. The rare form of synaesthesia - a condition where senses intermingle - came to light after a student reported "hearing sounds" from a screensaver. Researchers at the California Institute of Technology then found three more people with the same condition, New Scientist magazine reported. Those affected performed better in tests of recognising visual patterns than those without the condition. A more common form of the condition is being able to perceive numbers or letters as colours. Several artists have been linked with the condition, including David Hockney who is able to see colour when listening to music. Dr Melissa Saenz discovered the phenomenon when a group of students were being shown around her lab and one asked if anyone else could hear a pattern of moving dots on a computer screen. When she questioned him further she realised he matched the criteria for synaesthesia - he had experienced it all his life and it happened with lots of different moving images. By sending the moving dots image to hundreds of other volunteers, she found three others who could also hear sounds, such as tapping, whirring or whooshing, when watching it. (C)BBC

Keyword: Miscellaneous
Link ID: 11909 - Posted: 08.07.2008

By Melissa Dahl When Bill Russell tells people that his severe depression was relieved by shock therapy, the most common response he gets is: "They're still doing that?" Most people might be quicker to associate electroshock therapy with torture rather than healing. But since the 1980s, the practice has been quietly making a comeback. The number of patients undergoing electroconvulsive therapy, as it's formally called, has tripled to 100,000 a year, according to the National Mental Health Association. During an ECT treatment, doctors jolt the unconscious patient's brain with an electrical charge, which triggers a grand mal seizure. It's considered by many psychiatrists to be the most effective way to treat depression especially in patients who haven't responded to antidepressants. One 2006 study at Wake Forest University School of Medicine in North Carolina found that ECT improved the quality of life for nearly 80 percent of patients. Story continues below ↓advertisement "It's the definitive treatment for depression," says Dr. Kenneth Melman, a psychiatrist at Swedish Medical Center in Seattle who practices ECT. "There aren't any other treatments for depression that have been found to be superior to ECT." In fact, antidepressants — the most widely used method for treating depression — don't work at all for 30 percent of patients. © 2008 Microsoft

Keyword: Depression
Link ID: 11908 - Posted: 06.24.2010

It may take just one tobacco cigarette for some people to get addicted to nicotine because of how their brains are wired, a Canadian study suggests. By manipulating receptors in the brains of rats, the researchers were able to control whether the first exposure to nicotine was enjoyable or repulsive. The study appears in the Aug. 6 issue of the Journal of Neuroscience. "During the early phase of tobacco exposure, many individuals find nicotine highly unpleasant and aversive, whereas others may become rapidly dependent on nicotine and find it highly rewarding," said Steven Laviolette, a professor of anatomy and cell biology at the University of Western Ontario. "We wanted to explore that difference," he added in a release. The team experimented on two types of receptors for dopamine, a chemical messenger in the brain's reward circuitry. By blocking the receptors, the researchers were able to switch how nicotine was processed — from repulsive to rewarding or positive. The natural variations that occur between people may explain why some are more likely to become addicted to nicotine. © CBC 2008

Keyword: Drug Abuse
Link ID: 11907 - Posted: 06.24.2010

By Robert Stickgold and Jeffrey M. Ellenbogen In 1865 Friedrich August Kekulé woke up from a strange dream: he imagined a snake forming a circle and biting its own tail. Like many organic chemists of the time, Kekulé had been working feverishly to describe the true chemical structure of benzene, a problem that continually eluded understanding. But Kekulé’s dream of a snake swallowing its tail, so the story goes, helped him to accurately realize that benzene’s structure formed a ring. This insight paved the way for a new understanding of organic chemistry and earned Kekulé a title of nobility in Germany. Although most of us have not been ennobled, there is something undeniably familiar about Kekulé’s problem-solving method. Whether deciding to go to a particular college, accept a challenging job offer or propose to a future spouse, “sleeping on it” seems to provide the clarity we need to piece together life’s puzzles. But how does slumber present us with answers? The latest research suggests that while we are peacefully asleep our brain is busily processing the day’s information. It combs through recently formed memories, stabilizing, copying and filing them, so that they will be more useful the next day. A night of sleep can make memories resistant to interference from other information and allow us to recall them for use more effectively the next morning. And sleep not only strengthens memories, it also lets the brain sift through newly formed memories, possibly even identifying what is worth keeping and selectively maintaining or enhancing these aspects of a memory. When a picture contains both emotional and unemotional elements, sleep can save the important emotional parts and let the less relevant background drift away. It can analyze collections of memories to discover relations among them or identify the gist of a memory while the unnecessary details fade—perhaps even helping us find the meaning in what we have learned. © 1996-2008 Scientific American Inc.

Keyword: Sleep; Learning & Memory
Link ID: 11906 - Posted: 06.24.2010

By Susan Milius That fish over there chasing the small female — he probably doesn’t really like her. He’s just acting that way because another guy’s watching. This scenario plays out among the small silvery-gray fish called Atlantic mollies (Poecilia mexicana), says Martin Plath of the University of Potsdam in Germany and the University of Oklahoma in Norman. A male molly tends to switch his mating preferences to the opposite of his usual ones when a rival male molly shows up, Plath and his colleagues report in the Aug. 5 Current Biology. When a male molly pursues a female, other males tend to chase her, too, Plath says. Thus he and his colleagues propose that switching preferences in front of a rival could deflect the competition’s interest to a less desirable female. The finding adds to a growing body of evidence that social environment affects mating preferences, Plath says, adding another layer of complexity to the study of sexual choices and evolution. Or it could be that mollies offer a rare example of documented deception among fish, Plath says. “You expect it among ravens,” he says, since the cognitively advanced birds trick observers while hiding food. “The funny thing here is that it’s a small gray fish.” © Society for Science & the Public 2000 - 2008

Keyword: Sexual Behavior
Link ID: 11905 - Posted: 06.24.2010

Kurt Kleiner Mimicking the curves of a human retina has enabled a digital image sensor to take wide-angle pictures without distortion. This is possible thanks to an improved method of transferring silicon sensors onto a curved surface. The electronic eyeball design can allow small cameras to capture wide-angle views with low distortion. That could be useful in a range of situations, from policing, to attaching cameras to wildlife. Conventional film and digital cameras use a flat surface to capture an image and as a result are unable to capture a wide field of view without distortion. Optics designed to correct such distortions can be complex and expensive. The concave retina of your eye is able to capture a wider field of view without distortion. But building similarly curved electronic image sensors is difficult. Silicon doesn't bend easily and can't be forced into a hemispherical form without creases appearing in the material. John Rogers at the University of Illinois at Urbana-Champagne and colleagues have now worked out a way around those problems, using conventional chip manufacturing technology. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 11904 - Posted: 06.24.2010

LONDON - Eating tuna and other fatty fish may help prevent memory loss in addition to reducing the risk of stroke, Finnish researchers said on Monday. People who ate baked or broiled — but not fried — fish high in omega-3 fatty acids have been found to be less likely to have “silent” brain lesions that can cause memory loss and dementia and are linked to a higher risk of stroke, said Jyrki Virtanen of the University of Kuopio in Finland. “Previous findings have shown that fish and fish oil can help prevent stroke, but this is one of the only studies that looks at fish’s effect on silent brain (lesions) in healthy, older people,,” Virtanen, who led the study, said in a statement. Omega-3 fatty acids are also found in salmon, mackerel, herring, sardines, and in other foods such as walnuts. They have been shown to provide an anti-inflammatory effect and have been linked to a lower risk of heart disease. The Finnish team studied 3,660 people aged 65 and older who underwent brains scans five years apart to detect the silent brain lesions, or infarcts, found in about 20 percent of otherwise healthy elderly people The researchers found that men and women who ate omega-3-rich fish three times or more per week had a nearly 26 percent lower risk of having silent brain lesions. Copyright 2008 Reuters.

Keyword: Alzheimers
Link ID: 11903 - Posted: 06.24.2010