Most of us assume that a hospital injection must have medicine in it to do any good, but University of Michigan psychiatrist Jon-Kar Zubieta proved that assumption wrong. He found that if he told patients that an injection contained an experimental painkiller--even though it actually contained nothing but salt water--most of them reported a decrease in the pain they felt from a previous shot. We may call it "mind over matter"; doctors call it the placebo effect. "The placebo effect has been known for a long time," Zubieta says. "Specifically in the context of pain, there is a clear effect of reductions of pain ratings by subjects when they believe that they are receiving a substance that is active, even though it is really inactive." In the early days of medicine when anatomy was poorly understood, the placebo effect--which occurs when a "dummy treatment" has positive therapeutic effects because a patient believes it will work--was a crucial component of all medical treatment. As medical knowledge progressed, scientists began to make educated guesses as to how the placebo effect worked, hypothesizing that the human brain could make its own painkilling chemicals and release them under certain high-stress circumstances. But because of technological limitations, no one was able to objectively observe these chemical processes--until now. © ScienCentral, 2000-2006. All

Keyword: Pain & Touch
Link ID: 8356 - Posted: 06.24.2010

One of the puzzling questions in the evolution of bees is how some species developed social behaviors. Arizona State University Life Sciences associate professor Gro Amdam thinks part of the answer can be traced back to bee reproductive traits. A paper describing Amdam's experiments, "Complex social behavior derived from maternal reproductive traits," is the cover story of the current issue (Jan. 5, 2006) of Nature. Additional authors include M. Kim Fondrk and Robert Page from Arizona State University, and Angela Csondes from the University of California, Davis. Honeybees live in highly complex communal societies that include divisions of labor among worker bees. Workers are female bees whose jobs include cleaning, maintaining and defending the hive, raising the young and foraging for nectar and pollen. Other species of bees, like carpenter bees, do not engage in social behavior and instead lead solitary lives. This has prompted researchers to look into how social structures and divisions of labor have arisen in bees from their solitary ancestors. Amdam's research supports the idea that elements of the reproductive behavior of those ancestors evolved to form a basis for social living and divisions of labor.

Keyword: Evolution
Link ID: 8355 - Posted: 01.04.2006

A person’s liking for a particular brand name is wired into a specific part of the brain, a new study reveals. The research may provide an insight into the brain mechanisms that underlie the behavioural preferences that advertisers attempt to hijack. It has long been known that humans and animals can learn to associate an irrelevant stimulus with a positive experience, for example the ringing of a bell with food, as in the case of Pavlov’s dogs. And neuroimaging studies have recently implicated two regions buried deep in the brain – the ventral striatum and the ventral midbrain – as having an important role in this learning. But now work led by John O’Doherty, currently at Caltech in Pasadena, US, shows that the actual level of preference is encoded in these brain regions, and that people access this information to guide their decisions. “The key message of our study is that we are able to make use of neural signals deep in our brain to guide our decisions about what items to choose, say when choosing between particular soups in a supermarket, without actually sampling the foods themselves,” says Doherty, who did the research while at University College London, UK. “This is because we can make use of our prior experiences of the items through which we fashioned subjective preferences – do I like it or not?” he told New Scientist. “The next time we come to make a decision we use those preferences.” © Copyright Reed Business Information Ltd.

Keyword: Emotions
Link ID: 8354 - Posted: 06.24.2010

A new UCLA imaging study shows that age-related breakdown of myelin, the fatty insulation coating the brain's internal wiring, correlates strongly with the presence of a key genetic risk factor for Alzheimer disease. The findings are detailed in the January edition of the peer-reviewed journal Archives of General Psychiatry and add to a growing body of evidence that myelin breakdown is a key contributor to the onset of Alzheimer disease later in life. In addition, the study demonstrates how genetic testing coupled with non-invasive evaluation of myelin breakdown through magnetic resonance imaging (MRI) may prove useful in assessing treatments for preventing the disease. "Myelination, a process uniquely built up in humans, arguably is the most important and most vulnerable process of brain development as we mature and age. These new findings offer, for the first time, compelling genetic evidence that myelin breakdown underlies both the advanced age and the principal genetic risks for Alzheimer disease," said Dr. George Bartzokis, professor of neurology at UCLA's David Geffen School of Medicine.

Keyword: Alzheimers; Genes & Behavior
Link ID: 8353 - Posted: 01.03.2006

By Elizabeth Agnvall Special to The Washington Post Just as we're taking down the tree, organizing the new toys and stepping onto the scale comes a study finding that may make us wonder why we do it all: Parents are more likely to be depressed than people who do not have children. Published last month in the Journal of Health and Social Behavior, the study of 13,000 U.S. adults found that parents, from those with young children to empty nesters, reported being more miserable than non-parents. The researchers analyzed data from a national survey of families and households that asked respondents how many times in the past week, for example, they felt sad, distracted or depressed. Unlike earlier studies, this one found moms and dads equally unhappy. So: After all the sleepless nights and drowsy mornings, the cycles of feeding and throwing up, the American Girl doll accessories bought on credit, the toothpick models of the solar system and the algebra tutors . . . we would have been happier without it all? In a word, says study author Robin Simon, an associate professor of sociology at Florida State University, yes. © 2006 The Washington Post Company

Keyword: Emotions; Sexual Behavior
Link ID: 8352 - Posted: 06.24.2010

By ANAHAD O'CONNOR THE FACTS Some old bromides - like the one that holds that chocolate causes acne - were just plain wrong. But when it comes to one piece of dietary advice that many of us were brought up on, the old wisdom prevails: fish is apparently food for the brain. Like many old wives' tales about food and eating, how this claim got started is not entirely clear. Some believe that it may have grown out of a theory that humans evolved in coastal areas because certain nutrients in fish, particularly omega-3 fatty acids, were necessary for brain development. But whatever the origin of the claim, multiple studies have provided some evidence to support it. One study this year at Harvard, which looked at 135 mothers and their infants, found that the more fish the mothers ate during their second trimesters, the better their infants did on tests when they were 6 months old. But the researchers urged mothers to stick to canned light tuna or salmon while steering clear of shark, swordfish and other types of fish with high mercury levels. Copyright 2006 The New York Times Company

Keyword: Development of the Brain
Link ID: 8351 - Posted: 01.03.2006

By NICHOLAS BAKALAR They may not have hot flashes or experience drastic mood swings. But a new study of captive female gorillas suggests that like human females the animals go through physiological changes when their reproductive days are ending. Sylvia Atsalis, a co-author of the study and a primatologist at the Brookfield Zoo in Chicago, said, "Like humans, gorillas seem to go not only through menopause, but also through perimenopause, during which we have documented some hormonal changes and during which there is reduced likelihood of conception." Some scientists theorize that menopause is evolutionarily adaptive, giving grandmothers an opportunity to help with child care or leave mothers more time to care for existing offspring. Others see it as merely an artifact of the increased life span of animals in captivity, having no survival value for a species. In the study, researchers monitored the menstrual patterns of 30 gorillas in 11 zoos by measuring daily fecal samples for progesterone, the hormone whose levels increase sharply just after ovulation. Of the animals, 22 were older than 30, the age at which gorillas begin to have reduced pregnancy rates and poor survival of offspring. Of the 22, five had clearly passed through menopause and seven were in perimenopause. The oldest, a menopausal 51-year-old, last gave birth at age 11, but mated with her partner until she was 49. Copyright 2006 The New York Times Company

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8350 - Posted: 01.03.2006

By NATALIE ANGIER WASHINGTON, - If the mere sight of Tai Shan, the roly-poly, goofily gamboling masked bandit of a panda cub now on view at the National Zoo isn't enough to make you melt, then maybe the crush of his human onlookers, the furious flashing of their cameras and the heated gasps of their mass rapture will do the trick. Cute cues are those that indicate extreme youth, vulnerability, harmlessness and need, scientists say. "Omigosh, look at him! He is too cute!" "How adorable! I wish I could just reach in there and give him a big squeeze!" "He's so fuzzy! I've never seen anything so cute in my life!" A guard's sonorous voice rises above the burble. "OK, folks, five oohs and aahs per person, then it's time to let someone else step up front." The 6-month-old, 25-pound Tai Shan - whose name is pronounced tie-SHON and means, for no obvious reason, "peaceful mountain" - is the first surviving giant panda cub ever born at the Smithsonian's zoo. And though the zoo's adult pandas have long been among Washington's top tourist attractions, the public debut of the baby in December has unleashed an almost bestial frenzy here. Some 13,000 timed tickets to see the cub were snapped up within two hours of being released, and almost immediately began trading on eBay for up to $200 a pair. Copyright 2006 The New York Times Company

Keyword: Evolution; Vision
Link ID: 8349 - Posted: 01.03.2006

Reduced volume, or atrophy, in parts of the brain known as the amygdala and hippocampus may predict which cognitively healthy elderly people will develop dementia over a six-year period, according to a study in the January issue of Archives of General Psychiatry, one of the JAMA/Archives journals. New strategies may be able to prevent or delay the onset of Alzheimer's disease (AD), the most common cause of dementia among older adults, according to background information in the article. Accurate methods of identifying which people are at high risk for dementia in old age would help physicians determine who could benefit from these interventions. There is evidence that adults with AD and mild cognitive impairment, a less severe condition that is considered a risk factor for AD, have reduced hippocampal and amygdalar volumes. However, previous research has not addressed whether measuring atrophy using magnetic resonance imaging (MRI) can predict the onset of AD at an earlier stage, before cognitive symptoms appear. Tom den Heijer, M.D., Ph.D., of the Erasmus Medical Center, Rotterdam, the Netherlands, and colleagues used MRI to assess the brain volumes of 511 dementia-free elderly people who were part of the Rotterdam Study, a large population-based cohort study that began in 1990. They screened the participants for dementia at initial visits in 1995 and 1996 and then in follow-up visits between 1997 and 2003, during which they asked about memory problems and performed extensive neuropsychological testing. The authors also monitored the medical records of all participants. During the follow-up, 35 participants developed dementia and 26 were diagnosed with AD.

Keyword: Alzheimers
Link ID: 8348 - Posted: 01.03.2006

By David Brown, Washington Post Staff Writer In medical research, nobody is convinced by a single experiment. A finding has to be reproducible to be believable. Only if different scientists in different places do the same study and get the same outcomes can physicians have confidence the finding is actually true. Only then is it ready to be put into clinical practice. Nevertheless, one of medicine's most overlooked problems is the fact that some questions keep being asked over and over. Repeated tests of the same diagnostic study or treatment are a waste -- of time and money, and of volunteers' trust and self-sacrifice. Unnecessary clinical trials may also cost lives. All this is leading some experts to ask a new question: "What part of 'yes' don't doctors understand?" Two papers dramatically illustrated this problem last year and may have helped nudge the medical establishment toward doing something about it. One article examined 18 years of research on aprotinin, a drug used to reduce bleeding during heart surgery. The other looked at studies on the relationship between a baby's sleeping position and sudden infant death syndrome. Both concluded that research on these subjects went on long after the answers were known -- namely, that aprotinin worked and that babies sleeping on their backs were less likely to die of SIDS. © 2006 The Washington Post Company

Keyword: Sleep
Link ID: 8347 - Posted: 06.24.2010

Researchers have developed a new tool to help them study endangered whales – autonomous hydrophones that can be deployed in the ocean to record the unique clicks, pulses and calls of different whale species. Those efforts are leading to some surprising findings, including the discovery by a team of researchers of rare right whales swimming in the Gulf of Alaska. "There has been only one confirmed sighting of a right whale in the Gulf of Alaska since 1980, so discovering them is not only surprising, it is fairly significant," said David K. Mellinger, an assistant professor at Oregon State University's Hatfield Marine Science Center in Newport. "We picked up the sounds of one whale off Kodiak Island, and several others in deep water, which is also something of a surprise, since most right whale sightings have been near-shore." Results of these and five years of studies have been published in the January 2006 issue of the journal BioScience. Mellinger said scientists have been able to use the hydrophones to distinguish sounds made by different whale species. And some species, he added, have different "dialects" depending on where they are from. Blue whales off the Pacific Northwest sound different than populations of blue whales that live in the western Pacific Ocean, and those sound different from populations of blue whales off Antarctica. And they all sound different than the blue whales off Chile.

Keyword: Hearing; Animal Communication
Link ID: 8346 - Posted: 06.24.2010

Initial results of the nation's largest clinical trial for depression have helped clinicians to track "real world" patients who became symptom-free and to identify those who were resistant to the initial treatment. Participants treated in both medical and specialty mental health care settings experienced a remission of symptoms in 12 to 14 weeks during well-monitored treatment with an antidepressant medication. The study, funded by the National Institutes of Health's (NIH) National Institute of Mental Health (NIMH), used flexible adjustment of dosages based on quick and easy-to-use clinician ratings of symptoms and patient self-ratings of side effects. About a third of participants reached a remission or virtual absence of symptoms during the initial phase of the study, with an additional 10 to 15 percent experiencing some improvement. Subsequent phases of the trials will help determine successful treatments for the nearly two thirds of those patients who were identified as treatment-resistant to a first medication in phase one. The trial, known as the STAR*D study -- Sequenced Treatment Alternatives to Relieve Depression -- included 2,876 participants and was conducted over six years at a cost of $35 million. (For more information on STAR*D, go to: http://www.clinicaltrials.gov/ct/show/NCT00021528?order=1).

Keyword: Depression
Link ID: 8345 - Posted: 01.02.2006

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