Chickadees are those tiny birds that sing their own name, but researchers say they are not looking for attention, they're picking a fight. University of Washington biologist Chris Templeton says if you ever hear a chickadee scream "chick-a-dee-dee-dee-dee," you ought to take cover, because them's fightin' words! "We've seen chickadees take on cats, we've seen chickadees take on owls, and we've seen chickadees take on eagles," he says. As reported in Discover magazine, Templeton set up an outdoor aviary in Montana where he kept flocks of chickadees. He collected sound recording of the chickadees in order to learn more about what their 16 different calls mean. "Not only do they have all these different types of calls but the way that they say each call may have different meanings," Templeton explains. The way chickadees sing their notorious chick-a-dee-dee call is an expression of how they feel about predators. When Templeton tethered owls, hawks, and eagles, as well as a cat and a ferret to pedestals inside the aviary he discovered that the chickadees use the "dee" in their song to call their flock mates to action and to tell them how dangerous a nearby predatory may be. The more dees in their call, the bigger the danger. © ScienCentral, 2000-2006.

Keyword: Sexual Behavior; Animal Communication
Link ID: 8665 - Posted: 06.24.2010

Electrical impulses foster myelination, the insulation process that speeds communication among brain cells, report researchers at two institutes of the National Institutes of Health. “This finding provides important information that may lead to a greater understanding of disorders such as multiple sclerosis that affect myelin, as well as a greater understanding of the learning process,” said Duane Alexander, M.D., Director of the NICHD. The study appears in the March 16 Neuron and was conducted by researchers at the National Institute of Child Health and Human Development and the National Cancer Institute. Neurons — specialized cells of the brain and nervous system — communicate via a relay system of electrical impulses and specialized molecules called neurotransmitters, explained the study’s senior author, R. Douglas Fields, Ph.D., Head of NICHD’s Nervous System Development and Plasticity Section. A neuron generates an electrical impulse, causing the cell to release its neurotransmitters, he said. The neurotransmitters, in turn, bind to nearby neurons. The recipient neurons then generate their own electrical impulses and release their own neurotransmitters, triggering the process in still more neurons, and so on. Neurons conduct electrical impulses more efficiently if they are covered with an insulating material known as myelin, Dr. Fields added. Layers of myelin are wrapped around the fiber-like projections of neurons like electrical tape wrapped spiral-fashion around an electrical cable. Human beings are born with comparatively little myelin, and neurons become coated with the material as they develop. Moreover, mental activity appears to influence myelination, Dr Fields said. For example, neglected children have less myelin in certain brain regions than do other children.

Keyword: Glia; Multiple Sclerosis
Link ID: 8664 - Posted: 06.24.2010

A rare opportunity to study patients with an intractable form of epilepsy has led to the identification of specific neurons in the human brain that respond to novel or familiar objects. The discovery was made using micro-thin electrodes that read electrical activity from single neurons inside the brains of patients who were undergoing treatment to determine the origin of their epileptic seizures. The research by Howard Hughes Medical Institute scientists and their colleagues may help researchers understand how the human brain distinguishes new objects from more familiar objects, a skill crucial to survival. The research group, which was led by Howard Hughes Medical Institute investigator Erin Schuman at the California Institute of Technology, reported their findings in the March 16, 2006, issue of the journal Neuron. First author Ueli Rutishauser of Caltech and co-author Adam Mamelak of Huntington Memorial Hospital and Cedars-Sinai Medical Center collaborated on the studies with Schuman. Prior to these studies, researchers had only identified regions of the human brain involved in detecting novel images or objects using functional magnetic resonance imaging. Those studies yielded conflicting evidence about whether such neurons existed in the learning centers of the brain - the hippocampus and amygdala. The hippocampus is involved in learning and memory, and the amygdala helps to etch memories that are associated with emotions such as fear. © 2006 Howard Hughes Medical Institute.

Keyword: Vision; Epilepsy
Link ID: 8663 - Posted: 06.24.2010

Vulnerability to both alcohol and nicotine abuse may be influenced by the same genetic factor, according to a recent study supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH). In the study, two genetically distinct kinds of rat – one an innately heavy-drinking strain bred to prefer alcohol ("P" rats), the other strain bred to not prefer alcohol ("NP" rats) -- learned to give themselves nicotine injections by pressing a lever. Researchers found that P rats took more than twice as much nicotine as NP rats. Their findings were reported recently in the Journal of Neuroscience. "Our findings suggest that the genetic factor underlying the high alcohol consumption seen in P rats may also contribute to their affinity for nicotine," said lead author A.D. Lê, Ph.D., a NIAAA-supported researcher at Toronto's Centre for Addiction and Mental Health and University of Toronto. Researchers have known for some time that people who smoke are more likely to drink alcohol than non-smokers. Similarly, smoking is three times more common in people with alcoholism than in the general population. Since previous studies have also determined that genetics plays an important role in both alcohol and nicotine addictions, researchers have hypothesized that the same gene or genes may influence the co-abuse of these substances.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 8662 - Posted: 06.24.2010

By GARDINER HARRIS An unusual number of deaths among patients in a large study of Aricept, the most popular drug to treat Alzheimer's disease, is raising concern among federal drug officials and some disease experts. In the study, of 974 patients who suffered from dementia related to heart disease, 11 deaths occurred among the patients taking Aricept, while no deaths occurred among those taking dummy pills. The Food and Drug Administration is examining the results of the study, said Susan Bro, an agency spokeswoman. The agency undertook a quick review of earlier Aricept studies and found no cause for concern, Ms. Bro said. "The drug remains a safe option for patients who are receiving it," she said. But experts in Alzheimer's disease said that the new study should not be dismissed and that it might indicate that Aricept and similar drugs increased the risks of heart disease. Because Aricept's benefits in fighting Alzheimer's disease are at best mild, any increase in risk should cause concern, they said. "These drugs are well known to slow the heart and constrict the respiratory passage ways," said Dr. Lon Schneider, a professor of psychiatry, neurology and gerontology at the University of Southern California. Copyright 2006 The New York Times Company

Keyword: Alzheimers
Link ID: 8661 - Posted: 03.17.2006

Botulinum neurotoxin A can be either the greatest wrinkle remover or one of the world's most potent biological weapons. To perform either job, however, the toxin must first find a way to enter cells. But understanding how the toxin — one of seven neurotoxins produced by the bacterium Clostridium botulinum — enters nerve cells has proved elusive for scientists. Despite a decade-long search for the receptor by labs around the world, researchers had come up empty handed. Now, a research team led by Howard Hughes Medical Institute (HHMI) researcher Edwin R. Chapman reports that it has identified the cellular receptor for botulinum neurotoxin A. The group's work was published in the March 16, 2006, edition of ScienceXpress, which provides electronic publication of selected Science papers in advance of print. The finding offers important new insights that suggest how the toxin shuts down nerve cells with deadly efficiency. In the clinic, the toxin, which is also known as botox, is used to treat forehead wrinkles, migraine headaches, urinary retention, eye muscle disorders, and excessive sweating. The same toxin also has more nefarious uses, and is considered a potential bioterror threat because it can kill people by paralyzing motor nerves in diaphragm muscles, causing breathing to stop. Lack of knowledge about the identity of the cell surface receptor that botulism toxin A uses to invade nerve cells has hindered the development of new antidotes to the toxin. © 2006 Howard Hughes Medical Institute.

Keyword: Neurotoxins
Link ID: 8660 - Posted: 06.24.2010

Commentary by Jennifer Granick If we can put a man on the moon, why can't we detect when someone is lying? Just as the space program seemed to be just the thing for combating communism during the Cold War, lie detection looks like just what we need in the fight against terrorism. The popular press, including Wired magazine, has been pretty optimistic that a high-tech replacement for the archaic and mistrusted polygraph machine is coming soon. Last weekend, Stanford Law School hosted a workshop called "Reading Minds: Lie Detection, Neuroscience, Law and Society," where attendees took a closer look at the technology -- a look that suggests we're still light years away. As a criminal defense attorney, I found the polygraph test useful, and I submitted my clients to testing on several occasions. There's little evidence that the polygraph is accurate, and most courts won't admit test results as evidence. But many people in law enforcement, including the FBI, believe in lie detectors, so strapping a defendant to a polygraph can be a useful tool in convincing prosecutors to drop borderline charges. One time, I got to sit in the room as the examiner, paid by our firm, strapped and clipped the sensors to our high-strung, jittery female client. The machine looked like something out of the 1950s, with wires and electrodes connected to needles that marked variations on a roll of paper. The test measures the subject's changes in respiration, heartbeat and perspiration -- anxiety reactions allegedly correlated with lying. © Copyright 2006, Lycos, Inc.

Keyword: Stress
Link ID: 8659 - Posted: 06.24.2010

Even for scientists, it's not every day you see a hairless mouse glowing bright green under a fluorescent light. And for scientists searching for stem cells that could grow into nerve or brain cells, seeing such a mouse meant finding a possible whole new source of such cells. The scientists had given the mouse a gene so that areas would glow green where such stem cells might be found. They expected part of the mouse around the head to glow green. Instead, the entire mouse was aglow. "I'll never forget the minute that we made that observation," says Robert Hoffman, president of AntiCancer, Inc., where the finding took place. Because of that moment, which Hoffman says was, in fact, a "lucky discovery," company scientists have been working on what could be a new source of adult stem cells. Their most recent research, published in Proceedings of the National Academy of Sciences (PNAS), shows that they've been able to use stem cells taken from a mouse hair follicle to help regenerate damaged nerves in mice. In previous research, also published in PNAS, they showed the stem cells could become special brain cells called neurons. © ScienCentral, 2000-2006.

Keyword: Stem Cells
Link ID: 8658 - Posted: 06.24.2010

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