Sid Perkins More than one-fifth of living mammal species are bats, and most of those use echolocation to track prey or avoid obstacles. The fossil record of these delicate-boned creatures is sparse, but analyses hint that even the earliest known bats—those flitting through the skies between 54 million and 50 million years ago—could echolocate, says Nancy B. Simmons, a vertebrate paleontologist at the American Museum of Natural History in New York City. In fact, of the six bat species previously known from that era and with enough remains to analyze, all apparently were sonar capable, she notes. Evidence includes a large cochlea, or inner ear, that enabled the bats to detect the echoes of their high-pitched squeaks. Paleontologists have long debated whether bats' ability to fly preceded, followed, or evolved in tandem with their ability to echolocate. Now, in the Feb. 14 Nature, Simmons and her colleagues describe the almost complete fossils of a creature that suggests the "flight-first" hypothesis is correct. The ancient bat, dubbed Onychonycteris finneyi, had a 30-centimeter-wingspan and lived in what is now western Wyoming about 52.5 million years ago, says Simmons. Onychonycteris, which means "clawed bat" in Greek, refers to the creature's most distinctive feature: It has claws on all five digits of its forelimbs, whereas all living bats and previously studied fossil bats have claws on no more than two digits. The name finneyi honors the fossil collector who excavated the specimens, says Simmons. ©2008 Society for Science & the Public.

Keyword: Hearing; Evolution
Link ID: 11311 - Posted: 06.24.2010

Diabetes is known to impair the cognitive health of people, but now scientists have identified one potential mechanism underlying these learning and memory problems. A new National Institutes of Health (NIH) study in diabetic rodents finds that increased levels of a stress hormone produced by the adrenal gland disrupt the healthy functioning of the hippocampus, the region of the brain responsible for learning and short-term memory. Moreover, when levels of the adrenal glucocorticoid hormone corticosterone (also known as cortisol in humans) are returned to normal, the hippocampus recovers its ability to build new cells and regains the "plasticity" needed to compensate for injury and disease and adjust to change. The study appears in the Feb. 17, 2008, issue of Nature Neuroscience and was conducted by the NIA's Mark Mattson, Ph.D., and colleagues. "This research in animal models is intriguing, suggesting the possibility of novel approaches in preventing and treating cognitive impairment by maintaining normal levels of glucocorticoid," said Richard J. Hodes, M.D., NIA director. "Further study will provide a better understanding of the often complex interplay between the nervous system, hormones and cognitive health." Cortisol production is controlled by the hypothalamic-pituitary axis (HPA), a hormone-producing system involving the hypothalamus and pituitary gland in the brain and the adrenal gland located near the kidney. People with poorly controlled diabetes often have an overactive HPA axis and excessive cortisol produced by the adrenal gland. To study the interaction between elevated stress hormones and the hippocampal function, researchers tested the cognitive abilities and examined the brain tissue in animal models of rats with Type 1 diabetes (insulin deficient) and mice with Type 2 diabetes (insulin resistant).

Keyword: Learning & Memory; Hormones & Behavior
Link ID: 11310 - Posted: 02.20.2008

By GINA KOLATA One of the great unanswered questions in physiology is why muscles get tired. The experience is universal, common to creatures that have muscles, but the answer has been elusive until now. Scientists at Columbia say they have not only come up with an answer, but have also devised, for mice, an experimental drug that can revive the animals and let them keep running long after they would normally flop down in exhaustion. For decades, muscle fatigue had been largely ignored or misunderstood. Leading physiology textbooks did not even try to offer a mechanism, said Dr. Andrew Marks, principal investigator of the new study. A popular theory, that muscles become tired because they release lactic acid, was discredited not long ago. In a report published Monday in an early online edition of Proceedings of the National Academy of Sciences, Dr. Marks says the problem is calcium flow inside muscle cells. Ordinarily, ebbs and flows of calcium in cells control muscle contractions. But when muscles grow tired, the investigators report, tiny channels in them start leaking calcium, and that weakens contractions. At the same time, the leaked calcium stimulates an enzyme that eats into muscle fibers, contributing to the muscle exhaustion. In recent years, says George Brooks of the University of California, Berkeley, muscle researchers have had more or less continuous discussions about why muscles fatigue. It was his work that largely discredited the lactic-acid hypothesis, but that left a void. Copyright 2008 The New York Times Company

Keyword: Muscles
Link ID: 11309 - Posted: 02.20.2008

By BENEDICT CAREY Artful persuasion depends on eye contact, but not just any kind. If one person prefers brief glances and the other is busy staring deeply, then it may not matter how good the jokes are or how much they both loved “Juno.” Rhythm counts. Voice cadence does, too. People who speak in loud, animated bursts tend to feed off others who do the same, just as those who are lower key tend to relax in a cool stream of measured tones. “Myself, I’m very conscious of people’s body position,” said Ray Allieri of Wellesley, Mass., a former telecommunications executive with 20 years in marketing and sales. “If they’re leaning back in their chair, I do that, and if they’re forward on their elbows, I tend to move forward,” Psychologists have been studying the art of persuasion for nearly a century, analyzing activities like political propaganda, television campaigns and door-to-door sales. Many factors influence people’s susceptibility to an appeal, studies suggest, including their perception of how exclusive an opportunity is and whether their neighbors are buying it. Most people are also strongly sensitive to rapport, to charm, to the social music in the person making the pitch. In recent years, researchers have begun to decode the unspoken, subtle elements that come into play when people click. Copyright 2008 The New York Times Company

Keyword: Language
Link ID: 11308 - Posted: 06.24.2010

By ANNIE MURPHY PAUL Twenty-five years ago, when Kanwaljeet Anand was a medical resident in a neonatal intensive care unit, his tiny patients, many of them preterm infants, were often wheeled out of the ward and into an operating room. He soon learned what to expect on their return. The babies came back in terrible shape: their skin was gray, their breathing shallow, their pulses weak. Anand spent hours stabilizing their vital signs, increasing their oxygen supply and administering insulin to balance their blood sugar. "What’s going on in there to make these babies so stressed?” Anand wondered. Breaking with hospital practice, he wrangled permission to follow his patients into the O.R. “That’s when I discovered that the babies were not getting anesthesia,” he recalled recently. Infants undergoing major surgery were receiving only a paralytic to keep them still. Anand’s encounter with this practice occurred at John Radcliffe Hospital in Oxford, England, but it was common almost everywhere. Doctors were convinced that newborns’ nervous systems were too immature to sense pain, and that the dangers of anesthesia exceeded any potential benefits. Anand resolved to find out if this was true. In a series of clinical trials, he demonstrated that operations performed under minimal or no anesthesia produced a “massive stress response” in newborn babies, releasing a flood of fight-or-flight hormones like adrenaline and cortisol. Potent anesthesia, he found, could significantly reduce this reaction. Babies who were put under during an operation had lower stress-hormone levels, more stable breathing and blood-sugar readings and fewer postoperative complications. Anesthesia even made them more likely to survive. Copyright 2008 The New York Times Company

Keyword: Pain & Touch; Development of the Brain
Link ID: 11307 - Posted: 06.24.2010

By BENEDICT CAREY AN expression of true love or raw hatred, of purest faith or mortal sin, of courageous loyalty or selfish cowardice: The act of suicide has meant many things to many people through history, from the fifth-century Christian martyrs to the Samurais’ hara-kiri to more recent literary divas, Hemingway, Plath, Sexton. But now the shadow of suicide has slipped into the corridors of modern medicine as a potential drug side effect, where it is creating a scientific debate as divisive and confounding as any religious clash. And the shadow is likely to deepen. After a years-long debate about whether antidepressant drugs like Prozac and Paxil increase the risk of suicide in some people, the Food and Drug Administration in recent days reported that other drugs, including medications used to treat epilepsy, also appear to increase the remote risk of suicide. The agency has been evaluating suicide risk in a variety of medicines, and more such reports — and more headlines — are expected. Many doctors who treat epilepsy patients said they were bewildered by the recent reports and concerned that regulators were scaring patients away from valuable medications based on limited evidence. On the other side, critics of the agency have charged that the reports were long overdue. Copyright 2008 The New York Times Company

Keyword: Depression
Link ID: 11306 - Posted: 06.24.2010

Nora Schultz Macaques may just seem to be indulging in monkey banter, but they can distinguish one another's voices in much the same way that humans do, suggests a new study. In the human brain, the "voice region" in the auditory cortex activates when we hear others speak. It had been unclear if the human voice area was a specialist adaptation that evolved with our spoken language skills. Now Chris Petkov at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, and colleagues have found that monkey brains, too, have a voice region. They played a variety of sounds to seven macaques and used fMRI to detect any brain areas with increased activity. One region, corresponding to a site close to the voice region in the human brain, lit up in response to macaque coos and grunts, but was less active when the monkeys heard other animals or natural sounds, such as those of insects, thunder and rain. Journal reference: Nature Neuroscience (DOI: 10.1038/nn2043) © Copyright Reed Business Information Ltd.

Keyword: Language; Hearing
Link ID: 11305 - Posted: 06.24.2010

By John Russell At first blush, Chuck Clauson seems to have as much energy as the next guy. He works full time as a bank loan officer, is raising two teenagers as a single dad, does plenty of housework and enjoys short walks. But the 40-year-old Pendleton man, who was diagnosed with multiple sclerosis nine years ago, admits he gets tired quickly, especially in hot weather. He takes five medications every day to treat an array of symptoms, from fatigue to nerve pain. Like many people who suffer from multiple sclerosis, Clauson wishes there were a single treatment, or even a cure, for the disease that affects 21/2 million people worldwide, including about 400,000 Americans. Indianapolis-based Eli Lilly and Co. is pushing to find a new treatment. Better known for developing medicine for diabetes, depression and schizophrenia, Lilly recently signed a deal with a Canadian biotechnology company, BioMS Medical Corp., to help it complete development of an experimental drug called MBP9289. The two companies say MBP9289 has shown promise in delaying progression and worsening of multiple sclerosis. The drug is in two Phase 3 clinical trials and one Phase 2 trial, and is still years away from the market.

Keyword: Multiple Sclerosis
Link ID: 11304 - Posted: 02.11.2008

Nigel Hawkes Consuming low-calorie drinks may increase the risk of putting on weight, according to scientists in the United States. They have suggested that people who choose diet drinks containing artificial sweeteners tend to overcompensate and consume more calories than those who do not. Although the rise in obesity has corresponded with a growth in low-calorie soft drinks, designed to make keeping weight down easy by replacing sugar with saccharine or other sweeteners, scientists who conducted experiments using rats at Purdue University, in Indiana, have suggested that the opposite may be happening. They found that rats fed on yoghurt sweetened with saccharine ate more calories, gained more weight and put on more body fat than rats that were given yoghurt sweetened with glucose. Susan Swithers and Terry Davidson, who conducted the experiments, have suggested that, by breaking the connection between a sweet sensation and high-calorie food, the use of saccharine changes the body’s ability to regulate how many calories it consumes. “The data clearly indicate that consuming a food sweetened with no-calorie saccharine can lead to greater body-weight gain and adiposity than would consuming the same food sweetened with a higher-calorie sugar,” they conclude in their report, which is published in the journal Behavioural Neuroscience. © Copyright 2008 Times Newspapers Ltd.

Keyword: Obesity
Link ID: 11303 - Posted: 06.24.2010

BOSTON - If you’re sad and shopping, watch your wallet: A new study shows people’s spending judgment goes out the window when they’re down, especially if they’re a bit self-absorbed. Study participants who watched a sadness-inducing video clip offered to pay nearly four times as much money to buy a water bottle than a group that watched an emotionally neutral clip. The so-called “misery is not miserly” phenomenon is well-known to psychologists, advertisers and personal shoppers alike, and has been documented in a similar study in 2004. The new study released Friday by researchers from four universities goes further, trying to answer whether temporary sadness alone can trigger spendthrift tendencies. The study found a willingness to spend freely by sad people occurs mainly when their sadness triggers greater “self-focus.” That response was measured by counting how frequently study participants used references to “I,” “me,” “my” and “myself” in writing an essay about how a sad situation such as the one portrayed in the video would affect them personally. The brief video was about the death of a boy’s mentor. Another group watched an emotionally neutral clip about the Great Barrier Reef, the vast coral reef system off Australia’s coast. © 2008 The Associated Press

Keyword: Emotions; Depression
Link ID: 11302 - Posted: 06.24.2010

Doctors are increasingly prescribing exercise for people with depression, mental health campaigners have found. In a survey of 200 English GPs, the Mental Health Foundation found 22% suggest exercise to help people with milder forms of the condition. This compares with just 5% in a similar survey three years ago. The foundation said it was important that doctors did not just prescribe antidepressants for patients, and looked for other options. Research has shown that exercise can help people with mild forms of depression by improving self-esteem - through better body image or achieving goals, and by relieving feelings of isolation which can fuel their depression. It also releases feel-good brain chemicals such as endorphins. Celia Richardson, campaigns director for the Mental Health Foundation, said: "It can help people physically, socially and biologically. They often meet others who have been in the same situation as them, but are now further down the line and feeling better." The survey found there is now a wider belief by GPs that exercise therapy can be beneficial. (C)BBC

Keyword: Depression
Link ID: 11301 - Posted: 02.09.2008

By Yvonne Raley and Robert Talisse In 2003 nearly half of all Americans falsely assumed that the U.S. government had found solid evidence for a link between Iraq and al Qaeda. What is more, almost a quarter of us believed that investigators had all but confirmed the existence of weapons of mass destruction in Iraq, according to a 2003 report by the University of Maryland’s Program on International Policy Attitudes and Knowledge Networks, a polling and market research firm. How did the true situation in Iraq become so grossly distorted in American minds? Many people have attributed such misconceptions to a politically motivated disinformation campaign to engender support for the armed struggle in Iraq. We do not think the deceptions were premeditated, however. Instead they are most likely the result of common types of reasoning errors, which appear frequently in discussions in the news media and which can easily fool an unsuspecting public. News shows often have an implicit bias that may motivate the portrayal of facts and opinions in misleading ways, even if the information presented is largely accurate. Nevertheless, by becoming familiar with how spokespeople can create false impressions, media consumers can learn to ignore certain claims and thereby avoid getting duped. We have detected two general types of fallacies—one of them well known and the other newly identified—that have permeated discussion of the Iraq War and that are generally ubiquitous in political debates and other discourse. (C)1996-2007 Scientific American Inc.

Keyword: Emotions
Link ID: 11300 - Posted: 06.24.2010

By David A. Fahrenthold and Steven Mufson A federal appeals court yesterday threw out the Environmental Protection Agency's approach to limiting mercury emitted from power-plant smokestacks, saying the agency ignored laws and twisted logic when it imposed new standards that were favorable to plant owners. The ruling, issued by the U.S. Court of Appeals for the D.C. Circuit, was another judicial rejection of the Bush administration's pollution policies. It comes less than a year after the U.S. Supreme Court rebuked the administration and the EPA for refusing to regulate greenhouse gases. This court's critique -- which undid a controversial program to "trade" emissions of mercury, a potent neurotoxin -- was especially sharp. It compared the EPA to the capricious Queen of Hearts in "Alice's Adventures in Wonderland," saying the agency had followed its own desires and ignored the "plain text" of the law. "What the administration did when they came in was to essentially try to torpedo environmental regulations," said James Pew, a lawyer with the activist group Earthjustice who worked on the case. "This really is a repudiation of the Bush administration's environmental legacy." Coal-fired power plants are responsible for about a third of the country's total mercury emissions. In the Washington area, mercury pollution in waterways has triggered advisories against consuming too much fish from the Chesapeake Bay, the Potomac River and other bodies of water. © Copyright 1996-2008 The Washington Post Company

Keyword: Neurotoxins; Development of the Brain
Link ID: 11299 - Posted: 06.24.2010

By M. P. DUNLEAVEY WHEN I invited a friend to dinner one day last summer, she mentioned that she would bring some Blue Nun white wine, in a box. If you’re not accustomed to hearing the words “box” and “wine” in the same sentence, the idea might sound unappealing. Perhaps even déclassé. Not that I wanted to admit these thoughts to my friend, but my exclamation — “Blue Nun? In a box?” — did make my skepticism rather clear. Fortunately she just laughed at my snobbery, and said that boxed wine today was far from the old Chablis with a spigot, which some of us may recall from college bars and family picnics. She even used the word “tasty” — which although not top of the oenophile vocabulary, sounded promising. And she was right. Blue Nun in a box was surprisingly tasty, all things considered, and the embarrassing experience of having my cheap wine prejudice exposed has forced me to examine how far this financial bias goes. I feared that the wine incident was evidence that somehow I actually believed that paying more for things means they’re better, even though I know it isn’t true. There is research suggesting that the bias toward higher-priced goods may have something to do with the way the brain links price with pleasure — and thus leads people to make assumptions about quality. Copyright 2008 The New York Times Company

Keyword: Emotions
Link ID: 11298 - Posted: 06.24.2010

Tina Hesman Saey Peter Pan won't be pleased to hear the latest theory about how Prozac works. A new study shows that the antidepressant stimulates growth of neurons in the hippocampus and speeds the young brain cells toward maturity. The maturation process could be the mechanism by which the drug relieves depression. Fluoxetine, the drug commonly known as Prozac, has been used to treat depression since the 1980s. Prozac and other SSRIs (selective serotonin reuptake inhibitors) block the ability of the neurons to take up serotonin, thereby raising levels of the active neurotransmitter in the brain. When people with depression begin taking such drugs, serotonin levels in the brain increase rapidly, but it often takes 2 to 4 weeks before they begin to feel better. The new study, published Feb. 6 in the Journal of Neuroscience, suggests that the lag is due to the time it takes for serotonin to stimulate new neurons to grow, mature, and integrate into brain circuits. René Hen, a neuroscientist at Columbia University, and his colleagues tested the long-term effects of Prozac treatment on a specially bred strain of nervous mice. Inside the brains of mice treated with Prozac, the researchers found many more newborn neurons in the dentate gyrus of the hippocampus, a part of the brain involved in learning and memory. ©2008 Society for Science & the Public.

Keyword: Depression; Neurogenesis
Link ID: 11297 - Posted: 06.24.2010

By Robynne Boyd The human brain is complex. It enables concertos to be composed, manifestos made, and equations solved elegantly. It's also the wellspring of feelings, behaviors, experiences and the repository of memory. So it's no surprise that the brain remains a mystery. Adding to that mystery is the contention that humans "only" employ 10 percent of their brain. If only regular folk could tap that other 90 percent they too could become savants who remember pi to the 20,000th decimal place or perhaps even a psychic. Though an alluring idea, the "ten percent myth" is so wrong it is almost laughable, says neurologist Barry Gordon at Johns Hopkins University in Baltimore. While there’s no definitive culprit to the beginning of this legend, the notion has been linked to the American psychologist and author William James, who argued in The Energies of Men that “We are making use of only a small part of our possible mental and physical resources.” It's also been linked to Albert Einstein, who supposedly used it to explain his cosmic intellect. The myth's durability, Gordon says, stems from people's conceptions about their own brains: their own shortcomings demonstrate the existence of untapped gray matter. This is false. What is correct however, is that at certain moments in anyone's life, such as when we are simply sitting and thinking, we may be using only 10 percent of our brain. © 1996-2007 Scientific American Inc.

Keyword: Miscellaneous
Link ID: 11296 - Posted: 06.24.2010

James Owen Those who struggle to get out of bed in the morning may be able to hold their genes responsible, new research suggests. Scientists have discovered that a person's waking habits are mirrored by body cells that are equipped with their own daily alarm clocks. The work represents the first internal look at the biological clocks of those suffering from sleeping disorders, said study leader Steven A. Brown of the Institute for Pharmacology and Toxicology at the University of Zurich, Switzerland. "One of the big surprises was that so much of our daily behavior was genetically encoded," Brown said. "The idea that skin cells are telling us anything about our behavior was, for me, quite fascinating," he added. The study investigated the circadian rhythm—the brain-controlled phenomenon that governs various body functions over a 24-hour period—of extreme late and early risers. Suitable volunteers were recruited by the study team using TV advertisements shown between 3 a.m. and 4 a.m. "We got both our early types and our late types that way," Brown said. "Some had not yet gone to bed, while others were already up." Skin cells taken from the volunteers were cultured in the lab and injected with a bioluminescence gene found in fireflies. © 1996-2008 National Geographic Society

Keyword: Biological Rhythms; Genes & Behavior
Link ID: 11295 - Posted: 06.24.2010

Patients with a certain gene variant drank less and experienced better overall clinical outcomes than patients without the variant while taking the medication naltrexone, according to an analysis of participants in the National Institutes of Health's 2001-2004 COMBINE (Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence) Study. About 87 percent of patients with the variant who received naltrexone experienced good outcomes, compared with about 49 percent of those who received a placebo. About 55 percent of patients without the variant experienced a good outcome regardless of whether they received naltrexone or placebo. Good outcome was defined as abstinence or moderate drinking without related problems, according to an article in the Feb. 4 issue of the Archives of General Psychiatry (http://archpsyc.ama-assn.org/cgi/content/abstract/65/2/135). Drinking alcohol increases the release of endogenous opioids, compounds that originate in the body and promote a sense of pleasure or well-being. An opioid antagonist, naltrexone blocks brain receptors for endogenous opioids, making it easier for patients to remain abstinent or stop quickly in the event of a slip. In clinical studies, naltrexone has been shown to reduce relapse and craving for alcohol in some but not all treated patients. Earlier studies had suggested that a specific DNA variant of the opioid receptor gene (OPRM1) might have role in patients' response to naltrexone. "Analysis of the large COMBINE patient population increases confidence that the OPRM1 variant is in part responsible for positive responses to naltrexone." said National Institute on Alcohol Abuse and Alcoholism (NIAAA) director Ting-Kai Li, M.D.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 11294 - Posted: 02.08.2008

By Elizabeth Quill Johann Sebastian Bach, Edgar Allan Poe, and Albert Einstein all married cousins. Maybe these creative geniuses were on to something. A new study suggests that mating with relatives has reproductive advantages. Many societies regard inbreeding as taboo. Research seems to back this up, showing that children of related couples are more likely to inherit two copies of disease-causing recessive genes. Other work, however, has shown a positive outcome--namely, that married cousins have more children. But those studies--carried out in India and Pakistan--have not been conclusive because the data are hard to disentangle from social and economic factors. For example, poorer women tend not only to marry relatives but also to marry at a younger age, leaving more time to have children. Geneticist Kári Stefánsson and colleagues at deCODE Genetics, a biopharmaceutical company based in Reykjavik, Iceland, decided to look at couples in their own country. Social and economic factors are more uniform in Iceland because the income gap is not wide and there is little variation in family size, use of contraceptives, or marriage practices. In addition, because deCODE already had a genealogical database for all of Iceland going back 1000 years, Stefánsson says, the team just needed to do some calculations. After determining the relationships between all known Icelandic couples born between 1800 and 1965, they compared the number of children and grandchildren descended from these couples. © 2008 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 11293 - Posted: 06.24.2010

Becoming overweight as a child is more likely to be the result of your genes than your lifestyle, claims a study. University College London researchers examined more than 5,000 pairs of identical and non-identical twins. Their American Journal of Clinical Nutrition study found that differences in body mass index and waist size were 77% governed by genes. An anti-obesity group said regardless of genes, a balanced diet and exercise were vital to good health. Children who are overweight are likely to be overweight or obese in adulthood, raising the risk of certain cancers, heart disease, stroke and diabetes later in life. However, despite the emergence of some possible genes that contribute to obesity, there is still debate as to the extent to which we are pre-programmed to be overweight by our genetic makeup. The study, from the Cancer Research UK Health Behaviour Research Centre at UCL, goes some way to answering that question. Twin studies are a good way to test how far our genes or our environment influence our development. Identical twins have exactly the same genes, while non-identical twins are genetically different, like brother and sister. However, because they were born at the same time, and raised in the same household, they can be assumed to have roughly similar upbringing in terms of food. (C)BBC

Keyword: Obesity; Genes & Behavior
Link ID: 11292 - Posted: 02.07.2008