Maryann Mott for National Geographic News New Yorkers have them. So do Georgians, Texans, Brits, and Australians. Now primate researchers have discovered that Japanese macaques can acquire different accents based on where they live—just like humans. The red-faced monkeys frequently utter what researchers have dubbed coo calls to maintain vocal contact with one another. Recordings of these calls taken over an eight-year period show that macaques living hundreds of miles apart "speak" at different frequencies. The finding, the first of its kind, will appear in the January 2006 edition of the German scientific journal Ethology. "One of the characteristics of human language lies in its modifiability," said Nobuo Masataka, a professor of animal behavior at Kyoto University's Primate Research Institute, in an email to National Geographic News. "Japanese monkey vocalizations share this characteristic with our language." © 1996-2005 National Geographic Society.

Keyword: Language; Evolution
Link ID: 8344 - Posted: 06.24.2010

A single unifying physics theory can essentially describe how animals of every ilk, from flying insects to fish, get around, researchers at Duke University's Pratt School of Engineering and Pennsylvania State University have found. The team reports that all animals bear the same stamp of physics in their design. The researchers show that so-called "constructal theory" can explain basic characteristics of locomotion for every creature -- how fast they get from one place to another and how rapidly and forcefully they step, flap or paddle in relation to their mass. Constructal theory is a powerful analytical approach to describing movement, or flows, in nature. They said their findings have important implications for understanding factors that guide evolution by suggesting that many important functional characteristics of animal shape and locomotion are predictable from physics. The findings, published in the January 2006 issue of "The Journal of Experimental Biology," challenge the notion that fundamental differences between apparently unrelated forms of locomotion exist. The findings also offer an explanation for remarkable universal similarities in animal design that had long puzzled scientists, the researchers said.

Keyword: Evolution
Link ID: 8343 - Posted: 12.31.2005

By Jennifer Viegas, Discovery News — Laughter is either genuine or consciously feigned, according to a new analysis that details how laughter has evolved over the past seven million years. The study, published in the current Quarterly Review of Biology, is the first to emphasize that two types of laughter exist. The first type is spontaneous and stimulus-driven, while the second, with the rather sinister nickname "the dark side of laughter," is strategic and, at times, downright cruel. Matthew Gervais, lead author of the study, described the two types to Discovery News. "One type of laughter arises spontaneously from the perception of a certain class of events, while the other is used strategically in interaction to influence others or modulate one's own physiology," said Gervais, who is a researcher in the Evolutionary Studies Program at Binghamton University in New York. Analyzing past studies that contained data on ape features, such as oral-facial muscle control, as well as using theory and data on brain neurons, evolutionary psychology and other disciplines, Gervais and colleague David Sloan Wilson determined that genuine laughter is innate and mirrors ape play-panting, which arose around seven million years ago. © 2005 Discovery Communications Inc.

Keyword: Emotions; Evolution
Link ID: 8342 - Posted: 06.24.2010

Despite the prevailing belief that adult brain cells don't grow, a researcher at MIT's Picower Institute for Learning and Memory reports in the Dec. 27 issue of Public Library of Science (PLoS) Biology that structural remodeling of neurons does in fact occur in mature brains. This finding means that it may one day be possible to grow new cells to replace ones damaged by disease or spinal cord injury, such as the one that paralyzed the late actor Christopher Reeve. "Knowing that neurons are able to grow in the adult brain gives us a chance to enhance the process and explore under what conditions -- genetic, sensory or other -- we can make that happen," said study co-author Elly Nedivi, the Fred and Carole Middleton Assistant Professor of Neurobiology. While scientists have focused mostly on trying to regenerate the long axons damaged in spinal cord injuries, the new finding suggests targeting a different part of the cell: the dendrite. A dendrite, from the Greek word for tree, is a branched projection of a nerve cell that conducts electrical stimulation to the cell body. "We do see relatively large-scale growth" in the dendrites, Nedivi said. "Maybe we would get some level of improvement (in spinal cord patients) by embracing dendritic growth." The growth is affected by use, meaning the more the neurons are used, the more likely they are to grow, she said.

Keyword: Regeneration; Development of the Brain
Link ID: 8341 - Posted: 12.29.2005

A new gene therapy technique that has shown promise in skin disease and hemophilia might one day be useful for treating muscular dystrophy, according to a new study by researchers at Stanford University School of Medicine. In the study, scheduled to be published online in the Proceedings of the National Academy of Sciences the week of Jan. 2, the researchers used gene therapy to introduce a healthy copy of the gene dystrophin into mice with a condition that mimics muscular dystrophy. The dystrophin gene is mutated and as a result produces a defective protein in the roughly 20,000 people in the United States with the most common form of the disease. Using gene therapy to treat muscular dystrophy isn't a new idea. Thomas Rando, MD, PhD, associate professor of neurology and neurological sciences, said that researchers have tried several different techniques with variable success. One hurdle is getting genes into muscle cells all over the body. Another is convincing those cells to permanently produce the therapeutic protein made by those genes. The gene therapy technique Rando and postdoctoral fellow Carmen Bertoni, PhD, used was developed by Michele Calos, PhD, associate professor of genetics. One of the main advantages of this method is that it could potentially provide a long-term fix for a variety of genetic diseases, including muscular dystrophy.

Keyword: Muscles
Link ID: 8340 - Posted: 12.29.2005

A diet with a high intake of beta carotene, vitamins C and E, and zinc is associated with a substantially reduced risk of age-related macular degeneration in elderly persons, according to a study in the December 28 issue of JAMA. Age-related macular degeneration (AMD) is a degenerative disorder of the macula, the central part of the retina, and is the most common cause of irreversible blindness in developed countries, according to background information in the article. Late-stage AMD results in an inability to read, recognize faces, drive, or move freely. The prevalence of late AMD steeply increases with age, affecting 11.5 percent of white persons older than 80 years. In the absence of effective treatment for AMD, the number of patients severely disabled by late-stage AMD is expected to increase in the next 20 years by more than 50 percent to 3 million in the United States alone. Epidemiological studies evaluating both dietary intake and serum levels of antioxidant vitamins and AMD have provided conflicting results. One study (called AREDS) showed that supplements containing 5 to 13 times the recommended daily allowance of beta carotene, vitamins C and E, and zinc given to participants with early or single eye late AMD resulted in a 25 percent reduction in the 5-year progression to late AMD. Redmer van Leeuwen, M.D., Ph.D., of Erasmus Medical Centre, Rotterdam, the Netherlands, and colleagues investigated whether antioxidants, as present in normal daily foods, play a role in the primary prevention of AMD.

Keyword: Vision
Link ID: 8339 - Posted: 12.29.2005

By Shankar Vedantam, Washington Post Staff Writer The spiraling cost of post-traumatic stress disorder among war veterans has triggered a politically charged debate and ignited fears that the government is trying to limit expensive benefits for emotionally scarred troops returning from Iraq and Afghanistan. In the past five years, the number of veterans receiving compensation for the disorder commonly called PTSD has grown nearly seven times as fast as the number receiving benefits for disabilities in general, according to a report this year by the inspector general of the Department of Veterans Affairs. A total of 215,871 veterans received PTSD benefit payments last year at a cost of $4.3 billion, up from $1.7 billion in 1999 -- a jump of more than 150 percent. Experts say the sharp increase does not begin to factor in the potential impact of the wars in Iraq and Afghanistan, because the increase is largely the result of Vietnam War vets seeking treatment decades after their combat experiences. Facing a budget crunch, experts within and outside the Veterans Affairs Department are raising concerns about fraudulent claims, wondering whether the structure of government benefits discourages healing, and even questioning the utility and objectivity of the diagnosis itself. "On the one hand, it is good that people are reaching out for help," said Jeff Schrade, communications director for the Senate Veterans Affairs Committee. "At the same time, as more people reach out for help, it squeezes the budget further." © 2005 The Washington Post Company

Keyword: Stress
Link ID: 8338 - Posted: 06.24.2010

Howard Hughes Medical Institute researchers have discovered a molecular link between a high-fat, Western-style diet, and the onset of type 2 diabetes. In studies in mice, the scientists showed that a high-fat diet disrupts insulin production, resulting in the classic signs of type 2 diabetes. In an article published in the December 29, 2005, issue of the journal Cell, the researchers report that knocking out a single gene encoding the enzyme GnT-4a glycosyltransferase (GnT-4a ) disrupts insulin production. Importantly, the scientists showed that a high-fat diet suppresses the activity of GnT-4a and leads to type 2 diabetes due to failure of the pancreatic beta cells. The experiments point to a mechanistic explanation for why failing pancreatic beta cells don't sense glucose properly and how that can lead to impaired insulin production, said Jamey Marth, a Howard Hughes Medical Institute investigator at the University of California, San Diego (UCSD). Marth and first author Kazuaki Ohtsubo at UCSD collaborated on the studies with researchers from the Kirin Brewery Co. Ltd., and the University of Fukui, both in Japan. The discovery of the link between diet and insulin production offers new information that may aid in the development of treatments that target the early stages of type 2 diabetes.

Keyword: Obesity
Link ID: 8337 - Posted: 12.29.2005

By BENEDICT CAREY ANAHEIM, Calif. - The small car careered toward a pile of barrels labeled "Danger TNT," then turned sharply, ramming through a mock brick wall and into a dark tunnel. A light appeared ahead, coming fast and head-on. A locomotive whistled. "Uh-oh," said one of the passengers, Dr. Martin Seligman, a psychologist and a pioneer in the study of positive emotions. But in a moment, the car scudded safely under the light, out through the swinging doors of Mr. Toad's Wild Ride and into the warm, clear light that seemed to radiate from the Southern California pavement. "Well," Dr. Seligman said. "I don't know that I expected to be doing that." One of several prominent therapists who agreed to visit Disneyland at the invitation of this reporter, Dr. Seligman was here in mid-December for a conference on the state of psychotherapy, its current challenges and its future. And a wild ride it was. Because it was clear at this landmark meeting that, although the participants agreed it was a time for bold action, psychotherapists were deeply divided over whether that action should be guided by the cool logic of science or a spirit of humanistic activism. The answer will determine not only what psychotherapy means, many experts said, but its place in the 21st century. Copyright 2005 The New York Times Company

Keyword: Depression
Link ID: 8336 - Posted: 12.29.2005

J. Scott Yaruss Stuttering is a communication disorder generally characterized by involuntary disruptions in the flow of speech. These disfluencies can take many forms, such as repetitions of parts of words (“li-li-like this”) and moments when a sound or a period of silence is prolonged (“lllllike this” or “l-----ike this”). Individuals who stutter often experience negative emotional, cognitive or behavioral reactions that can further affect their ability to communicate. Ultimately, stuttering can have a significant adverse impact on an individual’s quality of life and ability to participate in daily activities. The stuttering classification encompasses a number of communication disorders: neurogenic stuttering and psychogenic stuttering are associated with sudden onset and, as their names imply, with a specific known cause--either a flaw in the makeup of the brain or a profound psychological challenge. These disorders are relatively rare and differ in terms of etiology, symptoms and treatment from developmental stuttering, the most common disorder. Developmental stuttering typically starts in early childhood, between the ages of two and a half and four. The onset of the disorder, which can be gradual or relatively sudden, generally occurs during the period of rapid development in a child’s language skills, motor skills, temperament, and social interaction. Later onset of developmental stuttering has also been reported, though less is known about this variant. The causes of developmental stuttering are not well understood and various theories have been offered throughout the history of speech-language pathology. The roots of stuttering have been attributed to a number of causes: emotional problems, neurological problems, inappropriate reactions by caregivers and family members, language planning, and speech motor difficulties, among others. © 1996-2005 Scientific American, Inc.

Keyword: Language; Development of the Brain
Link ID: 8335 - Posted: 06.24.2010

By Mary Beckman Marijuana has a reputation for making people dash to the kitchen (or the nearest convenience store). New research shows why and helps explain how a hormone called leptin usually keeps the appetite under control. The results may help scientists design better diet drugs. Researchers have known for several years that a connection exists between leptin and cannabinoids, the molecules in the brain that stimulate appetite and that are related to those found in marijuana (ScienceNOW, April 11 2001). Mice that don't make leptin have oversized appetites, for example, and they have unusually high concentrations of cannabinoids in the hypothalamus. But no one knew how leptin and cannabinoids interacted in the brain. To examine the relation, Young-Hwan Jo, now at the Albert Einstein College of Medicine, New York City, and colleagues, took a look at slices of mouse hypothalamus. When the team dropped a cannabinoidlike compound onto the neurons, the neurons fired. If the researchers added leptin first, the neurons did not activate. © 2005 American Association for the Advancement of Science.

Keyword: Obesity; Drug Abuse
Link ID: 8334 - Posted: 06.24.2010

Susan Milius New videos of ants fixing an entrée of fruit fly stew show that it's the youngsters who do the colony's version of cooking. What's more, they don't nibble as they cook but wait to be served their fair share. Ants prepare their meat not by heating but by marinating it with digestive enzymes to create a glistening protein slurry. With their hourglass figures, adult ants have such tiny waists that solid food can't pass through to their abdomens. Biologists already knew that the blob-shaped larvae predigest meat. Some scientists had suggested that the adults feed meat to the larvae and return later for some regurgitated protein slurry. That's not what happened, though, in videos of lab colonies of pinhead-size Pheidole spadonia, says Deby Cassill of the University of South Florida in St. Petersburg. Adults placed lumps of prey in little hairy depressions on top of the larvae's bellies, and for some 5 hours, larvae drooled digestive enzymes over the meat as it dissolved into a protein drink. The adults collected the slurry to distribute, but during the kitchen prep, the youngsters rarely took a swallow themselves. ©2005 Science Service.

Keyword: Evolution
Link ID: 8333 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Horses prefer fenugreek, banana and cherry-flavored feed to all other flavors, according to one of the most detailed studies yet on horse flavor preferences. Three of the most popular flavors added to commercial horse feed — molasses, garlic and mint — did not fare nearly as well. In fact, most horses in the study rejected garlic-flavored food, unless it was their only choice. According to the study, which is published in this month's Applied Animal Behavior Science, horses ranked flavors as follows: fenugreek, banana, cherry, rosemary, cumin, carrot, peppermint and oregano. Many horse enthusiasts in Western countries feed their horses apples, but the eight competition-breed horses in the study liked the flavor of bananas better. "Horses tend to be fed food that is cheap and local, so what they are offered will vary around the world," said Deborah Goodwin, lead author of the study. "We offer horses apples in the U.K., but in Japan they are expensive and people gift wrap them and give them to each other as presents." © 2005 Discovery Communications Inc.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8332 - Posted: 06.24.2010

Charlotte Schubert Our perception of colours can depend on whether we view them from the left or the right, scientists have found. They say this demonstrates how language can alter the way we see the world. The idea that language can affect cognition is not new. In the 1930s, the American linguist Benjamin Lee Whorf proposed the controversial hypothesis that the structure of language affects the way people think. Later studies have hinted that this may be true in some circumstances (see 'Tribes without names for numbers cannot count'). But whether language affects our perception of the world has remained an open question. Richard Ivry of the University of California, Berkeley, and colleagues suspected that separating out the effects of visual input to the right and left brain hemispheres might yield some clues. Language is processed mainly in the left hemisphere of the brain, which also deals with signals from the left side of the retinas in both our eyes. Because light from objects to our right falls mainly into the left-hand area of our retinas, the researchers hypothesized that colours to the right would feel the influence of language more keenly. Conversely, objects on our left side activate the right hemisphere of the brain, so the effect of language would be minimal. ©2005 Nature Publishing Group

Keyword: Vision; Laterality
Link ID: 8331 - Posted: 06.24.2010

Gaia Vince Reindeer have a body clock that does not rely on a 24-hour day/night light cycle, according to Norwegian researchers. It may explain how they stay awake to carry out their Christmas duties. Instead, the herbivores’ stomachs seem to keep their body clocks ticking along. Karl-Arne Stokkan at the University of Tromsø, and colleagues, logged the festive animals’ movements every 10 minutes for a year using a radio transmitter device embedded in collars around the reindeers’ necks. The collars were placed on 12 reindeer – six who roamed a mountainous region of mainland Norway at a latitude of 70° North, and six found in the more-northerly Arctic archipelago of Svalbard (78° N). Winter in these regions is unyieldingly dark, while in summer the Sun does not set. Spring and autumn provide just a few weeks of night/day cycles. In the absence of light stimuli humans, like most mammals, naturally revert to a 6 to 8-hour sleep pattern due to an inbuilt circadian rhythm. © Copyright Reed Business Information Ltd

Keyword: Biological Rhythms
Link ID: 8330 - Posted: 06.24.2010

By introducing expression of a special green-algae gene into neurons of the tiny, transparent nematode C. elegans, researchers have been able to elicit specific behavioral responses by simply illuminating animals with blue light. The work paves the way for better understanding of how neurons communicate with each other, and with muscles, to regulate behavior in intact, living organisms. Generally speaking, detailed information about the activity and function of specific neurons during particular behaviors has been difficult to achieve in undissected animals. The new findings are reported by Alexander Gottschalk and colleagues at Goethe-University Frankfurt and at the Max Planck Institute for Biophysical Chemistry, also in Frankfurt. In their new study, the researchers employed a light-sensitive protein from the green alga Chlamydomonas reinhardtii. This protein, channelrhodopsin-2 (ChR2), sits in cell membranes, where it gates the flow of certain ions from one side of the membrane to the other. Such so-called channel proteins play central roles in the activities of neurons and muscle cells, and while some channel proteins are sensitive to chemicals or electrical signals, ChR2 and its relatives are controlled directly by certain wavelengths of light, making them ideal for remote control in the laboratory. In their experiments, the researchers took advantage of the light sensitivity of the algal channel protein by introducing expression of a modified form of ChR2 in specific C. elegans neurons and muscle cells. The researchers found that when this form of ChR2 was expressed in muscle cells, blue-light activation of the protein was sufficient to cause strong contraction of the muscle. They found that muscle contraction was simultaneous with light exposure.

Keyword: Pain & Touch
Link ID: 8329 - Posted: 12.20.2005

By Stacey Colino, Special to The Washington Post Like most teenagers, Andrew Solomon was often at the mercy of his moods -- but in his case this situation persisted into his thirties. "During my up periods, I'm lucid and articulate," said Solomon, author of the partly autobiographical "The Noonday Demon: An Atlas of Depression," which won the National Book Award for nonfiction in 2001. "I have clarity and can see patterns in my work, and I can write loads of publishable material in one night. I'm also very affectionate with people I care about." But when his moods would turn, as they invariably did, he could withdraw or have angry outbursts. Once, after an annoying phone call, he slammed down the phone so hard it broke. Another time, when an acquaintance who frequently drank too much showed up at his home tipsy and immediately poured herself a cocktail, Solomon "smashed the glass and yelled at her that she had to leave immediately," he recalls. After such explosions, he would "spend the next week apologizing." Yet it wasn't until three years ago that Solomon, now 42, learned there is a word for the mood swings that have affected him since his youth: cyclothymia. Cyclothymic disorder, as it is sometimes known, is a milder cousin of bipolar disorder. Like bipolar disorder, cyclothymia has high and low phases, though the highs are not as high and the lows not as low. It can be crippling nonetheless. And it is a risk factor for bipolar disease itself, with up to 50 percent of those with cyclothymia eventually developing bipolar disorder. Major depression is also a higher risk. © 2005 The Washington Post Company

Keyword: Depression; Schizophrenia
Link ID: 8328 - Posted: 06.24.2010

Morphine and other opioids work wonders for pain. Unfortunately, their effectiveness declines over time while their addictiveness grows, meaning patients need the drug even as it affords them less and less relief. But new research into the cellular workings of opioids offers a promising new pathway to improved pain relief--without the addiction--by triggering one receptor and blocking another. Medicinal chemist Philip Portoghese of the University of Minnesota and his colleagues began by studying two of the four major opioid receptors in the cells of the central nervous system. Each bears the name of a Greek letter and the chemists focused on the Mu and Delta receptors. Previous research had shown that drugs that linked up with Mu receptors lasted longer with less addiction when combined with drugs that blocked Delta receptors. But it was not known whether the two channels worked separately or in concert to improve the overall effect. So Portoghese and his colleagues built a drug that triggered the Mu receptor while blocking the Delta receptor--dubbed MDAN, for Mu Delta agonist antagonist. They administered various versions of the drug to mice and then tested their sensitivity to pain by focusing a hot light on their tails and recording the time it took the animals to move them. The MDAN drug proved roughly 50 times more effective than morphine in blocking pain, the researchers report in this week's online edition of the Proceedings of the National Academy of Sciences. But MDAN still paled in comparison to drugs designed purely to stimulate the Mu receptor, which exhibit more than 100 times the pain blocking potential of morphine. The MDAN drugs had another benefit, however: the mice did not develop any dependence. © 1996-2005 Scientific American, Inc

Keyword: Pain & Touch; Drug Abuse
Link ID: 8327 - Posted: 06.24.2010

Our ability to understand speech or decide which fruit in the store is freshest depends on the brain's dexterity in integrating information over time. The prefrontal cortex, where working memory resides, plays a critical role in helping us make these countless everyday decisions. A novel computational study by Brandeis researchers in this week's issue of the Proceedings of the National Academy of Sciences proposes for the first time a neuronal model for the mechanisms underlying a time-related task in this complex decision-making process. Essentially, the study shows that neurons in the prefrontal cortex fire with greater or lesser intensity to finely control, or inhibit behavior, based on a neuronal feedback signal, or circuit mechanism. Such integral feedback control is probably at work in many regulatory areas of the body, such as temperature control and feelings of satiety to prevent overeating, but this is the first time this mechanism has been suggested as a role of neuronal firing. The findings provide a framework for understanding how neurons operate in a part of the brain that controls behavior and which is often compromised in people with mental health problems such as schizophrenia, a disease that can entail problems with short-term memory tasks and misperceptions about the immediate environment.

Keyword: Learning & Memory
Link ID: 8326 - Posted: 12.20.2005

Darwin’s fingerprints can be found all over the human genome. A detailed look at human DNA has shown that a significant percentage of our genes have been shaped by natural selection in the past 50,000 years, probably in response to aspects of modern human culture such as the emergence of agriculture and the shift towards living in densely populated settlements. One way to look for genes that have recently been changed by natural selection is to study mutations called single-nucleotide polymorphisms (SNPs) – single-letter differences in the genetic code. The trick is to look for pairs of SNPs that occur together more often than would be expected from the chance genetic reshuffling that inevitably happens down the generations. Such correlations are known as linkage disequilibrium, and can occur when natural selection favours a particular variant of a gene, causing the SNPs nearby to be selected as well. Robert Moyzis and his colleagues at the University of California, Irvine, US, searched for instances of linkage disequilibrium in a collection of 1.6 million SNPs scattered across all the human chromosomes. They then looked carefully at the instances they found to distinguish the consequences of natural selection from other phenomena, such as random inversions of chunks of DNA, which can disrupt normal genetic reshuffling. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 8325 - Posted: 06.24.2010