By Susan Brown Some parents will do anything to help their own offspring get ahead, even kill other babies. Lions and other pack leaders have earned a fearsome reputation for this, but a new study of meerkats shows that even females further down the pecking order are tempted to murder. The strategy is thought to help expecting mom's pups benefit more from the group's effort to raise them. Meerkats, a type of mongoose, share parenting duties to an unusual degree. Both males and females babysit while nursing mothers forage and bring pups treats such as beetle larvae. Females will even suckle young that are not their own. But one dominant female in each group monopolizes reproduction, in part by killing the offspring of subordinate females Over 80% of surviving young are her own. When behavioral ecologists Andrew Young and Tim Clutton-Brock of the University of Cambridge, U.K., saw dominant females evicting subordinates from the nesting burrow just before the dominant meerkats gave birth, they suspected the underlings may pose a threat to newborns. © 2006 American Association for the Advancement of Science

Keyword: Aggression; Sexual Behavior
Link ID: 8657 - Posted: 06.24.2010

People age 70 and older who continued taking the antidepressant that helped them to initially recover from their first episode of depression were 60 percent less likely to experience a new episode of depression over a two-year study period than those who stopped taking the medication, according to a study funded by the National Institute of Mental Health (NIMH), part of the National Institutes of Health. The study addresses a major question in the treatment of depression — when to discontinue medication. Published today in the March 16, 2006 New England Journal of Medicine, the study showed that long-term treatment (for at least 2 years) after a patient is symptom-free is effective in preventing future depressive episodes. “This study demonstrates the benefits of keeping older patients on an antidepressant long after they become symptom-free,” said NIMH’s director Thomas R. Insel, M.D. The clinical trial tested whether maintenance therapy — long-term treatment given to patients to enable them to maintain a symptom-free or disease-free state — is effective in preventing future episodes of depression in patients 70 years and older. It also tested whether antidepressant medication and psychotherapy were effective, and whether the extent of patients’ medical burden had an impact on rates of recurrence.

Keyword: Depression; Alzheimers
Link ID: 8656 - Posted: 06.24.2010

By Martin F. Downs The most prescribed sleep medication in the United States may be linked to episodes of sleepwalking and related strange and dangerous behaviors, experts say -- including incidents of nocturnal eating, phone conversations, shoplifting and even driving -- of which the subject has no memory. Sleep specialists and researchers cite a growing though still inconclusive body of reports associating Sanofi-Aventis's drug Ambien with the incidents. More than 24 million prescriptions for Ambien were written in 2004. Timothy Morgenthaler, a researcher at the Mayo Clinic Sleep Disorders Center in Rochester, Minn., says he has seen many cases of people who sleepwalk and sleep-eat after taking Ambien. He described five such cases in a 2002 report in the journal Sleep Medicine. All those patients stopped having sleep-eating episodes when they discontinued Ambien, Morgenthaler said. Since then he has seen many similar cases, he said. "I feel pretty comfortable that this is a real phenomenon," he said. Sanofi-Aventis, the French maker of the drug, declined to make officials available for interviews. The company issued a statement saying the side effect is known but rare, and that "when taken as prescribed, Ambien is a safe and effective treatment for insomnia." The side effect is disclosed in the product's full labeling material, where it is cited among numerous central nervous system side effects. © 2006 The Washington Post Company

Keyword: Sleep
Link ID: 8655 - Posted: 06.24.2010

By BENEDICT CAREY Antidepressants work better than psychotherapy in preventing relapses in elderly men and women who have recovered from depression, a new study suggests. The government-financed study, published today in The New England Journal of Medicine, found that a combination of drugs and therapy was the best way to restore well-being in seriously depressed patients 70 and older. Once the patients had recovered, however, drug treatment was more effective over the next two years than once-a-month psychotherapy. Experts said the results underscored the challenges of treating depression in people past retirement age who are buffeted by anxieties — about dying, losing friends, declining physical health — that are different from those of younger adult patients. The report also suggests that an orchestrated combination of psychotherapy, medication and careful case management followed by continued drug treatment can keep more than 40 percent of elderly people well for at least two years. Past studies have found that antidepressants alone are no better than placebos in relieving depression in people over 70, who tend to be more vulnerable to the drugs' side effects, including dizziness. But most of the estimated six million elderly Americans who suffer from depression receive little more than a prescription for an antidepressant if they receive treatment at all, psychiatrists say. Copyright 2006 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 8654 - Posted: 06.24.2010

By RICHARD A. FRIEDMAN, M.D. You would think the country is in the grip of an insomnia epidemic given the rising popularity of sleep drugs. Over the last five years, the use of hypnotics has increased by an astonishing 60 percent, according to IMS Health, a research company. Disturbed sleep has to be one of the most common complaints in medicine. Not only patients but the general public seems to have a cherished notion of what constitutes a normal night's sleep: seven to eight blissful hours of uninterrupted slumber. Many patients tell me they have a sleep problem because they wake up in the middle of the night for a time, typically 45 minutes to an hour, but fall uneventfully back to sleep. Curiously, there seems to be no consequence to this "problem." They are unaffected during the day and have plenty of energy and concentration to go about their lives. Being a psychiatrist, I am always on the lookout for illnesses like depression, anxiety disorders and drug or alcohol abuse that could easily produce sleep disturbance. But I often hear these complaints about interrupted sleep from patients in complete remission from their disorders, making it unlikely that this is a symptom of an untreated medical or psychiatric illness. Copyright 2006 The New York Times Company

Keyword: Sleep
Link ID: 8653 - Posted: 03.16.2006

(CBS) Are iPods and other portable music players hazardous to your hearing? It certainly can be if you turn the volume up too high or if you listen for long periods of time. The American Speech-Language-Hearing Association (ASHA) on March 14 announced the results of a survey it commissioned that found that "more than half of high school students surveyed report at least one symptom of hearing loss." Although teens were more likely to report problems than adults, adult listeners weren't off the hook. The survey, conducted by Zogby International, involved interviews with 1,000 adults and 301 teens. High school students, according to the survey, "are more likely than adults to say they have experienced three of the four symptoms of hearing loss." These are turning up the volume on their television or radio (28 percent students vs. 26 percent adults); saying "what?" or "huh?" during normal conversation (29 percent students vs. 21 percent adults); and tinnitus or ringing in the ears (17 percent students vs. 12 percent adults). Less than half the high school students (49 percent) say they have experienced none of these symptoms, compared to 63 percent of, according to the survey. Loud volume and prolonged exposure are both risk factors so adults, as well as kids, are vulnerable to hearing loss. ©MMVI, CBS Broadcasting Inc.

Keyword: Hearing
Link ID: 8652 - Posted: 06.24.2010

The insulating myelin sheath enwrapping the cable-like axons of nerve cells is the major target of attack of the immune system in multiple sclerosis. Such attack causes neural short-circuits that give rise to the muscle weakness, loss of coordination, and speech and visual loss in the disease. Now, Douglas Fields of the National Institute of Child Health and Human Development and his colleagues have reported in the March 16, 2006, issue of Neuron that supporting cells called astrocytes in the central nervous system (CNS) promote myelination by releasing an immune system molecule that triggers myelin-forming cells to action. The finding, they say, "may offer new approaches to treating demyelinating diseases." Astrocytes, so named because of their star-like shape, are the most prominent supporting cells in the nervous system. They provide critical regulatory molecules that enable nerve cells to develop and connect properly. In their studies, Fields and his colleagues sought to understand other research findings indicating that the electrical activity of nerve cells somehow triggers myelin-producing cells, called oligodendrocytes, to form the myelin membrane surrounding the nerve cells.

Keyword: Multiple Sclerosis; Glia
Link ID: 8651 - Posted: 03.16.2006

By Katherine Unger Some memories are best forgotten. But there's no such luxury for a woman known as 'AJ,' who remembers the details--what she did, who she was with--for every day of the past 30 years. Neuroscientists have coined the term "hyperthymestic syndrome" to describe this first-documented case of memory dominating a person's life. Nearly 6 years ago, neuroscientist James McGaugh of the University of California, Irvine, received an e-mail from then 34-year-old AJ asking for help. "[S]ince I was eleven I have had this unbelievable ability to recall my past," she wrote. She described her life as consumed by the "burden" of memories that were "non-stop, uncontrollable and totally exhausting." McGaugh and his colleagues arranged several meetings with AJ, where they asked her, without prior warning, to recall particular dates. One such "pop quiz" asked her to write down the dates of the previous 24 Easters. In 10 minutes, she produced a list of dates, along with what she had done that day. All the dates were correct, except for one that was off by 2 days. Two years later, the researchers sprung the same test on her, and she gave the exact same responses, but this time, all the dates were right. "She sort of has a vacuum cleaner sucking up all of the personal experiences and storing them away so that they're available" for recall, says McGaugh. © 2006 American Association for the Advancement of Science

Keyword: Learning & Memory
Link ID: 8650 - Posted: 06.24.2010

Whether depressed patients will respond to an antidepressant depends, in part, on which version of a gene they inherit, a study led by scientists at the National Institutes of Health (NIH) has discovered. Having two copies of one version of a gene that codes for a component of the brain’s mood-regulating system increased the odds of a favorable response to an antidepressant by up to 18 percent, compared to having two copies of the other, more common version. Since the less common version was over 6 times more prevalent in white than in black patients — and fewer blacks responded — the researchers suggest that the gene may help to explain racial differences in the outcome of antidepressant treatment. The findings also add to evidence that the component, a receptor for the chemical messenger serotonin, plays a pivotal role in the mechanism of antidepressant action. The study, authored by National Institute of Mental Health (NIMH) researchers Francis J. McMahon, M.D., Silvia Buervenich, Ph.D., and Husseini Manji, M.D., along with collaborators at several other institutions, was posted online March 8 and will appear in the May, 2006 American Journal of Human Genetics. “This discovery brings us closer to the day when clinicians will be able to offer treatment options and medications that are tailored and personalized to be optimally effective for individual patients,” said NIH Director Elias A. Zerhouni, M.D.

Keyword: Depression; Genes & Behavior
Link ID: 8649 - Posted: 06.24.2010

A swaying tree and a moving person activate distinctive areas of the brain's visual cortex, since recognizing people is essential for social interaction. So, an important question in exploring the visual system is how the visual cortex manages such specific recognition of "biological motion." In an article in the March 16, 2006, issue of Neuron, Marius Peelen and colleagues at the University of Wales, Bangor have used detailed functional magnetic resonance (fMRI) imaging of human volunteers to shed new light on this process. The widely used analytical technique of fMRI employs harmless magnetic fields and radio waves to measure blood flow in brain regions, which reflects brain activity in their region. In their experiments, the researchers found that in detecting biological motion the visual cortex not only uses a specific region known to detect motion of other people, but engages areas that respond to the static human form as well. The researchers designed their experiments to give subjects information only on biological motion and not on a human form. Specifically, they scanned the subjects' brains while showing them only "point-light" animation of human movement such as jumping or throwing. These animations consist only of a small number of white dots on a black background, not portraying skin, clothes, or other specific features of a human in action.

Keyword: Vision
Link ID: 8648 - Posted: 03.16.2006

Jacqueline Ruttimann The concave-eared torrent frog could give opera divas a run for their money. Reaching a pitch in the ultrasonic range, these frogs perform arias to be heard over the rushing waters of their habitat, the Huangshan Hot Springs in China. Ultrasonic communication uses sound at a frequency greater than the upper limits of human hearing, around 20 kilohertz, and is thought to exist only in certain mammals, such as bats, whales and some rodents. Now it seems that some frogs have evolved the ability to hit the high notes. Researchers have now measured the torrent frogs (Amolops tormotus) warbling at up to 34 kilohertz. "This is somewhat amazing," says Albert Feng, an acoustic specialist at the Beckman Institute at the University of Illinois, Urbana, and lead author of a paper in the latest issue of Nature1. Feng had previously noted the frogs' ability to sing in the ultrasonic range (see 'Frog sings like a bird'). But it wasn't clear until now that the frogs were actually using this to communicate, rather than it being a side-effect of more audible croaking. Many frogs have evolved visual signals to complement their croaks and make them more noticeable to mates, says herpetologist Michael Ryan of the University of Texas, Austin. The torrent frog, he says, seems to have taken a different tactic in its noisy environment. ©2006 Nature Publishing Group

Keyword: Hearing; Animal Communication
Link ID: 8647 - Posted: 06.24.2010

Helen Pearson A US team has identified what could be the earliest indication of Alzheimer's, a discovery that may help to diagnose the disease and perhaps stop it progressing. Researchers believe that some people show signs of memory loss years before they develop Alzheimer's. But they are not sure what causes these problems, or how they turn into full-blown dementia. To find out, Karen Ashe at the University of Minnesota, Minneapolis, and her team studied a strain of mice that, like people, develop mild memory problems in middle age before getting more severe Alzheimer's symptoms. The mice were genetically engineered to make a version of a human protein called amyloid-. Researchers know that this protein clogs the brains of Alzheimer's patients late in the disease. By extracting amyloid- from the animals' brains, the team discovered a knot of 12 proteins that appears outside brain cells just as memory loss occurs. These clusters, which it calls A*56, are different from the large plaques of amyloid- that form later in Alzheimer's patients. ©2006 Nature Publishing Group

Keyword: Alzheimers; Learning & Memory
Link ID: 8646 - Posted: 06.24.2010

Roxanne Khamsi Elderly patients taking certain drugs to lower their blood pressure appear to have a markedly reduced risk of Alzheimer’s disease, researchers report. Results from their short-term study suggest that some of these medications could slash this risk by up to 70%. Previous research has shown that high blood pressure, also known as hypertension, can increase a person’s chances of developing Alzheimer’s disease. Doctors commonly prescribe patients medications such as diuretics, which cause the kidneys to excrete water and salt, to lower blood pressure. Beta-blockers, which slow the heart rate and widen blood vessels, also work against hypertension. Doctors suspected that diuretics and beta-blockers could reduce the risk of dementia such as Alzheimer’s disease because these drugs improve blood-vessel function, perhaps helping the brain to receive better support. But studies exploring this possibility offered conflicting evidence. For this reason, Peter Zandi of the Johns Hopkins Bloomberg School of Public Health in Maryland, US, and his colleagues recruited elderly participants for their study in the mid 1990s and asked them about their use of medications such as beta-blockers and diuretics. Roughly half of the subjects in the study used antihypertensive drugs. And those taking these medicines typically used them for at least a couple of years. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 8645 - Posted: 06.24.2010

Researchers at the University of Minnesota Medical School and the Minneapolis VA Medical Center have for the first time identified a substance in the brain that is proven to cause memory loss. This discovery in mice gives drug developers a target for creating drugs to treat memory loss in people with dementia. The research, led by Professor of Neurology Karen H. Ashe, M.D., Ph.D., will be published in the March 16, 2006, issue of Nature. "Finding the specific cause of memory loss and cognitive decline gives scientists a protein complex to target," Ashe said. "Now we can begin to work on how that protein leads to the disease and what we can do to prevent it from harming the brain." Once the memory-robbing protein complex is better understood, drugs could be developed to stop Alzheimer's disease in its tracks. Currently about 4.5 million Americans live with Alzheimer's disease, a number that is projected to increase to 14 million in the next 20 years. In the past, it was generally accepted that Alzheimer's disease was caused by plaques and tangles, unnatural accumulations of two naturally occurring proteins in the brain: amyloid-beta, which builds into plaques between nerve cells in the brain; and tau, which forms the tangles bundles inside nerve cells. Ashe's lab proved last year that the tangles are not the cause of memory loss; this latest research shows the plaques aren't a major cause either.

Keyword: Alzheimers; Learning & Memory
Link ID: 8644 - Posted: 03.16.2006

Spinach may not give you popeye's super strengt, but digging into that spinach salad could help to protect you against the leading cause of blindness worldwide — cataracts — as well as helping your wasteline. "I've always been interested in the role of diet in disease," says nutrition researcher Joshua Bomser. He had a particular interest in the plant pigments that play a critical role in photosynthesis, known as carotenoids, that are found in many of the everyday fruits and vegetables we eat. "There's been some speculation that they can prevent the development of skin cancer, as well as the development of macular degeneration and age-related cataracts," he explains. "There are about 40 carotenoids that naturally occur in the diet. Of those, only lutein and zeaxanthin accumulate in the lens of the eye." Lutein and zeaxanthin are found in vegetables like kale, spinach and collard greens. So, Bomser and his colleagues at Ohio State University wanted to find out whether these plant pigments, which are found in high concentrations in dark green leafy vegetables, could protect the lens of the eye against the damaging ultraviolet rays of the sun and prevent cataracts. "We were able to show that lutein and zeaxanthin could reduce ultraviolet radiation induced damage in the lens," Bomser says. © ScienCentral, 2000-2006.

Keyword: Vision
Link ID: 8643 - Posted: 06.24.2010

It's hard not to look when you pass an accident on the road, but doing so can be dangerous. Vanderbilt University psychologist David Zald says "emotional" images — like car accidents, a gruesome murder scene, or a bit of pornography — can briefly blind us to everything else around us, limiting our senses and potentially putting us at risk. "Something that's emotional not only captures our attention, but it does it to such an extent that it's blocking information that comes in after. We're no longer even looking at that image," says Zald. As reported in Psychonomic Bulletin and Review, Zald and his colleagues trained twenty-one people to spot a neutral target image out of a series flying by at ten pictures per second, and then state whether it was rotated to the left or the right. The volunteers performed well except when either a gory or erotic image — more graphic than can be shown here — appeared before the target image. Co-author Steven Most, from Yale University, says in those cases participants were far more likely to miss the target. Zald says these emotional blindings happen all the time in our daily lives, but are probably most important for drivers, since a lapse in attention of less than a second is enough to cause an accident. © ScienCentral, 2000-2006.

Keyword: Attention; Vision
Link ID: 8642 - Posted: 06.24.2010

By John Bohannon Get a whiff of clove just as you sniff a rose, and the mix smells like carnation. How does our brain create such novel scents seemingly out of thin air? A new study of how the mouse brain responds to a variety of odors may offer an answer. An enduring mystery of smell is how humans can describe far more odors than they have nose receptors to detect. Smells begin when receptors--there are 347 different ones in humans--in the nose latch onto molecules in the air. The receptor then transmits a signal to the brain, which tells us what we're sniffing. Ostensibly, we should be able to distinguish the different scents that make them up, but this isn't always the case. One theory is that the brain sometimes mixes and matches signals that come from the nose to encode unique combo-scents. To test the idea, Linda Buck and Zhihua Zou, neuroscientists at the Fred Hutchinson Cancer Research Center in Seattle, Washington, and the University of Texas in Galveston, respectively, gave mice a whiff of chemicals that smell like either clove, chocolate, citrus, fish, vanilla, or apple. Some mice were exposed to individual scents while others sniffed two different ones at once. To see how the mice processed these smell signals, the researchers turned to the brain's smell center, the olfactory cortex. A gene called Arc is known to turn on when the neuron fires--so by tracking its expression in this region of the brain, the team could determine which neurons switched on in response to specific smells. © 2006 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8641 - Posted: 06.24.2010

By Mary Beckman Bug parents have it easy. Instead of suffering the starving cries of their babies like bird and mammal mommies do, new research indicates that insects merely need a whiff of their kids to gauge what little ones need. The new findings reveal a novel way for offspring to communicate hunger. Most larvae aren't blessed with a strong set of noisemakers. So it's a safe bet that they must get their parents' attention in some other way. Recognizing that bugs tend to use chemical signals to communicate with each other, evolutionary biologist Edmund Brodie III of Indiana University, Bloomington, wondered if baby insects speak by stinking. To find out, Brodie and colleagues looked at parental feeding behavior in burrower bugs (Sehirus cinctus). Adults are about the size of a pencil eraser, and the youngest babes--there can be up to 100 per brood--look like bright red pinheads. The researchers separated the babies into two groups: One got plenty to eat, while the other was underfed. They then collected the volatile chemicals wafting from each clutch. Finally, using a "smell-o-tron," the researchers blew these odors toward mother bugs. © 2006 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 8640 - Posted: 06.24.2010

Biologists at New York University have identified a key factor that enables photoreceptor cells to decide their color sensitivity. The findings, which were uncovered by researchers in Professor Claude Desplan's laboratory in NYU's Center for Developmental Genetics, were published in the March 9th issue of the journal Nature. The researchers used the fruit fly Drosophila as a genetic model system to study stochastic events like color sensitivity in photoreceptor cells. The eye of the fly contains some 800 optical units, called ommatidia. Each ommatidium contains six outer and two inner photoreceptors (R7 and R8); the inner receptors detect color, like cone cells in human eyes. Approximately 30 percent of the ommatidia are named "pale," with sensitivity to blue light, and about 70 percent are called "yellow," with sensitivity to green light. This ratio of 30 to 70 appears in a large number of diverse species of flies. However, these receptors are stochastically (or randomly) distributed. Desplan, the corresponding author of the article, said, "The key question we explored was how each individual R7 and R8 receptor 'decides' to be either 'pale' or 'yellow,' and how this 'decision' contributes to the stochastic distribution of each type in the mosaic of color photoreceptors in the fruit flies' eyes."

Keyword: Development of the Brain; Vision
Link ID: 8639 - Posted: 03.10.2006

Will Knight A computer controlled by the power of thought alone has been demonstrated at a major trade fair in Germany. The device could provide a way for paralysed patients to operate computers, or for amputees to operate electronically controlled artificial limbs. But it also has non-medical applications, such as in the computer games and entertainment industries. The Berlin Brain-Computer Interface (BBCI) – dubbed the "mental typewriter" – was created by researchers from the Fraunhofer Institute in Berlin and Charité, the medical school of Berlin Humboldt University in Germany. It was shown off at the CeBit electronics fair in Hanover, Germany. The machine makes it possible to type messages onto a computer screen by mentally controlling the movement of a cursor. A user must wear a cap containing electrodes that measure electrical activity inside the brain, known as an electroencephalogram (EEG) signal, and imagine moving their left or right arm in order to manoeuvre the cursor around. "It's a very strange sensation," says Gabriel Curio at Charité. "And you can understand from the crowds watching that the potential is huge." © Copyright Reed Business Information Ltd.

Keyword: Miscellaneous
Link ID: 8638 - Posted: 06.24.2010