By LIZETTE ALVAREZ AS marriage proposals go, this one was textbook: A Caribbean cruise, a night bursting with stars, a pitch-perfect dinner and then, after retiring to a private balcony, a bottle of Dom Pérignon. Ed Silcox Jr. dropped to one knee and presented an impeccable diamond ring to the bride-to-be, Johanna Murtha, who stifled tears. They scurried to bed, blissfully falling asleep in each other's arms. Then the farce began: Mr. Silcox, 46, started to snore: a cabin-rattling crescendo that built from minor rasp to mind-blowing snort. The snores blew past his new fiancée's foam earplugs, defied a stack of over-the-head pillows and rumbled down hallways. In no time Mr. Silcox was exiled to the balcony, where he slept night after night, braving the wind, the rising sun and a stream of dirty water from on high (as the deck hands cleaned the ship). A hotel in Puerto Rico offered little respite. In her desperation, Ms. Murtha, 40, chose to nap by the pool, in a howling thunderstorm, rather than snooze in bed next to her fiancé. "We spent every night apart and fought virtually every night of the week," said Ms. Murtha, now happily Ms. Murtha-Silcox, who lives outside Philadelphia. "By the end of the cruise I was thinking, 'What did I say yes for?' We were exhausted. Our eyes were falling out of our heads." Copyright 2005 The New York Times Company

Keyword: Sleep
Link ID: 8055 - Posted: 10.22.2005

La Jolla, CA - Delving ever deeper into the intricate architecture of the brain, researchers at The Salk Institute have now described how two different types of nerve cells, called neurons, work together in tiny sub-networks to pass on just the right amount and the right kind of sensory information. Their study, published online by Nature Neuroscience, depicts how specific types of inhibitory neurons in the visual cortex of a rat brain are wired to, and "talk" with, discrete excitatory neurons. They also show how that "conversation," aimed at keeping the right balance of chemical signals, often excludes surrounding neurons. "The inhibitory neurons are not just brakes, they can also be used to steer." said co-author Ed Callaway, Ph.D., associate professor in Salk's Systems Neurobiology Laboratories. For example, in vision, inhibitory responses in the visual cortex help people to focus on what they want to see, rather than all there is to see, he explained. This new study is filling in the picture of how the brain is organized into "smart" efficient networks, and researchers hope that details of this complex design might, one day, uncover the roots of such neurological diseases as schizophrenia. "We know already that schizophrenia is a problem with organization of inhibitory circuits of neurons, and now we are uncovering how these specialized nerve cells work together and with other neurons," Callaway explained.

Keyword: Vision
Link ID: 8054 - Posted: 10.22.2005

Christen Brownlee Two independent groups of scientists have devised ways to isolate embryonic stem cells from mice without destroying viable embryos. These new methods are intended to satisfy the ethical concerns of people who oppose destroying human embryos to do research or treat disease. Unlike any cell known in adults, embryonic stem cells can morph into virtually any of the body's cell types, such as nerve, muscle, or heart. Many researchers have proposed exploiting this unique capability to make new cells for the treatment of injuries or diseases such as Parkinson's disease (SN: 4/2/05, p. 218: http://www.sciencenews.org/articles/20050402/bob10.asp). However, to isolate a new line of embryonic stem cells, scientists have had to first destroy an early embryo. "Many people, including the President, are concerned about destroying life in order to save life," says Robert Lanza of Advanced Cell Technology in Worcester, Mass. Seeking to resolve this dilemma, Lanza and his colleagues looked to a technique commonly used to diagnose genetic diseases in embryos. Known as pre-implantation genetic diagnosis, the procedure removes one cell from an eight-cell-stage embryo and examines its DNA for defects. The remaining seven-cell embryo, after being implanted in the mother's womb, can develop into a normal baby. ©2005 Science Service.

Keyword: Stem Cells; Regeneration
Link ID: 8053 - Posted: 06.24.2010

By Lise Stevens, Contributing Writer The addition of testosterone to hormone therapy in women after menopause enhances their sexual function. However, it may also reduce HDL cholesterol (the “good” cholesterol) in women, according to a systematic review of current evidence. “If the reduction in HDL had been associated with an increase in triglycerides [fatty acids] or LDL cholesterol it would be of great concern,” said Dr. Susan Davis, professor of medicine at Monash University, Melbourne, Australia, and study co-author “However, as an isolated finding the significance is difficult to interpret.” She added, “Testosterone has not been found to alter other coronary heart disease risk factors.” The review appears in the most recent issue of The Cochrane Library, a publication of The Cochrane Collaboration. The study team reviewed 23 randomized clinical trials involving 1,957 patients who had testosterone added to their hormone replacement therapy (either estrogen or combined estrogen/progestin) for an average of six months. Testosterone was given orally in a majority of the studies in doses of either 1.25 mg. or 2.5 mg. Participants completed questionnaires that measured their sexual activity and libido, and were assessed for other side effects. Health Behavior News Service Washington, DC © 2005

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8052 - Posted: 06.24.2010

People could have an immunity to vCJD and similar diseases after persistent exposure to milder strains of the agent that causes them, scientists suggest. Experts at Yale University and Nagasaki University medical schools carried out studies on cells. Writing in Science magazine, they said regular doses of the weaker infection appeared to offer protection. A UK expert said further understanding of how the effect works could lead to a preventative therapy being developed. It might also help to explain why fewer people than predicted have died from vCJD. The US and Japanese researchers also put forward the theory that the diseases are caused by viruses. Misfolded proteins called prions are present in brain and nerve tissue infected with vCJD, and related diseases known as transmissible spongiform encephalopathies (TSEs). Other TSEs include classic CJD, BSE, which infects cattle, and scrapie, which infects sheep. But there is doubt as to whether prions are the cause of these diseases, or simply the result of them. Earlier research on animals showed a weaker strain of CJD appeared to offer protection against a more destructive strain. (C)BBC

Keyword: Prions
Link ID: 8051 - Posted: 10.22.2005

Scientists are developing a cochlear implant which could allow deaf people to hear music. Existing implants allow people to listen easily to speech, but not music. But a team at the UK's National Physical Laboratory have developed a device with a wider frequency range, which improves musical appreciation. New Scientist magazine reports the whole implant could be put into the ear - current models require people to wear a box behind their ears. The cochlea in the ear contains fluid and hairs which vibrate in response to sounds. These hairs can stop vibrating, meaning people go deaf. It can happen at any age but can be particularly difficult for children as it affects their ability to do well at school and socialise. Cochlear implants currently involve putting an electrode inside the ear and an external box, which contains a microphone to pick up the sound, converts it from radiowaves into electrical signals and contains batteries to power the implant. Conventional hearing aids simply amplify sound rather than making it clearer. (C)BBC

Keyword: Hearing
Link ID: 8050 - Posted: 10.20.2005

Researchers at the University of Toronto (U of T), Capital Health's Stollery Children's Hospital in Edmonton, Toronto's Hospital for Sick Children and their international collaborators have discovered a genetic abnormality that causes a type of language impairment in children – a discovery that could lead to isolating genes important for the development of expressive language. A study published in the Oct. 20 issue of the New England Journal of Medicine outlines the discovery of a genetic abnormality in a nine-year-old boy with learning difficulties and speech problems from northern Alberta. By using some of the latest genetic screening methods designed to look for differences in the amount of DNA in particular chromosomes, the researchers discovered that the boy carries additional copies (termed duplication) of around 27 genes on chromosome 7. This is only the second instance of the identification of a single chromosome region linked to specific language impairment. The boy can understand what is said to him at the level of a seven-year-old but his expressive language and speech are at the level of a two-and-a-half-year-old. "Our results show that changes in the copy number of specific genes can dramatically influence human language abilities," says senior author Lucy Osborne, a U of T professor of medicine. "Based on our findings, we are expanding the study to assess the frequency of this DNA duplication in children with expressive language delay."

Keyword: Language; Genes & Behavior
Link ID: 8049 - Posted: 06.24.2010

We all know the site of a tragic accident. A four by four tossed over a highway barrier. A white sheet on the ground. Police with heads bent. As we pass, it seems like the most courteous action would be to avert our eyes, but still we glance over to the awful scene. Vanderbilt University psychologist David Zald says that's dangerous because, what he calls "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. "When [visual] information comes into the brain it has to get funneled through a relatively small area… only so much information can pass though at a time," explains Zald. "So what happens is, if there's a piece of emotional information, it basically gets jammed into the space… and nothing else is passing through." Zald and a group of colleagues based at Yale University report in the November issue of Psychonomic Bulletin and Review that they trained 21 people to spot a target image among a series of pictures flying by on a computer screen at a rate of 10 pictures per second. The target image is what the researchers call a "neutral" image, such as a picture of a building or a landscape. Study participants had to determine if the target image was rotated to the left or the right. © ScienCentral, 2000-2005.

Keyword: Vision; Emotions
Link ID: 8048 - Posted: 06.24.2010

Researchers are now understanding in greater detail the molecular machinery underlying the short-term brain changes that produce the high of cocaine, as well as the longer-term changes behind addiction. Their findings offer hope for targeted drugs that can short-circuit that addiction machinery. In the October 20, 2005, issue of Neuron, researchers led by Eric J. Nestler and Arvind Kumar of The University of Texas Southwestern Medical Center have pinpointed a key molecular mechanism by which genes are switched on in the brain that govern both short-term and long-term effects of cocaine. Such activation is called transcriptional activation because it induces the gene to begin making copies of itself into messenger RNA that trigger protein production. In their experiments, the researchers studied a process called "chromatin remodeling"--in which the histone proteins enfolding genes are chemically altered to render the genes active. They administered to rats both short-term, acute cocaine doses and long-term, chronic cocaine and analyzed the alteration of the histones affecting specific genes involved in cocaine response in the brain.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 8047 - Posted: 10.20.2005

Fetal alcohol syndrome (FAS), a disorder that is indicated by distinct facial characteristics, growth retardation, and poor intellectual and attentional function, can occur when mothers drink alcohol heavily during pregnancy. A new study in the October issue of The Journal of Pediatrics shows that prenatal alcohol exposure can also affect an infant's visual acuity or sharpness of vision. Sandra W. Jacobson, Ph.D. and colleagues from Wayne State University and University of Cape Town evaluated 131 infants of mixed ancestry in Cape Town, South Africa. After interviewing each mother to ascertain her alcohol consumption during pregnancy, the authors tested the visual acuity of the infants at 6 ½ months of age using the Teller Acuity Cards (TAC) Test, which is comprised of gray cards with a concentration of vertical black and white stripes on the left or the right side. An examiner looked through a peephole in the center of the card to determine where the infant was looking. Poor visual acuity was indicated when the infant was not looking at the side containing the lines. Of the infants examined, 22 met the criteria for being diagnosed with FAS, and their visual acuity was significantly poorer than those without FAS. 27% of the infants with FAS scored below the fifth percentile, as opposed to the 9% of the infants without FAS. However, half of the infants with low TAC scores who did not meet the criteria for full FAS were born to mothers who reported binge drinking (greater than 5 drinks per occasion) during pregnancy.

Keyword: Drug Abuse; Vision
Link ID: 8046 - Posted: 10.20.2005

By GARDINER HARRIS The use of sleeping pills among children and very young adults rose 85 percent from 2000 to 2004, in yet another sign that parents and doctors are increasingly turning to prescription medications to solve childhood health and behavioral problems. And about 15 percent of people under age 20 who received sleeping pills were also being given drugs to treat attention deficit and hyperactivity disorder, according to the study by Medco Health Solutions, a managed-care company that makes estimates about medication use in the whole population based on extrapolations from its own data. Drugs used to treat attention disorders can cause insomnia. Few of the prescriptions given to children and young adults have the approval of the Food and Drug Administration because no sleep medication has been approved for use in children under 18. Still, doctors commonly use medications for patients and disorders for which the drugs have never received formal approval, particularly when those patients are children. Dr. Robert Epstein, Medco's chief medical officer, said, "It leads you to wonder whether these children are being treated for insomnia caused by hyperactivity or whether the medication itself causes the insomnia." The use of sleeping medicines among adults doubled from 2000 to 2004, Medco found. Copyright 2005 The New York Times Company

Keyword: Sleep
Link ID: 8045 - Posted: 10.19.2005

By BENEDICT CAREY They seem almost alive: snapshots of the living human brain. Not long ago, scientists predicted that these images, produced by sophisticated brain-scanning techniques, would help cut through the mystery of mental illness, revealing clear brain abnormalities and allowing doctors to better diagnose and treat a wide variety of disorders. And nearly every week, it seems, imaging researchers announce another finding, a potential key to understanding depression, attention deficit disorder, anxiety. Yet for a variety of reasons, the hopes and claims for brain imaging in psychiatry have far outpaced the science, experts say. Dr. Helen Mayberg of Emory found a baffling pattern of brain activity. After almost 30 years, researchers have not developed any standardized tool for diagnosing or treating psychiatric disorders based on imaging studies. Copyright 2005 The New York Times Company

Keyword: Depression; Brain imaging
Link ID: 8044 - Posted: 10.19.2005

By BENEDICT CAREY The Dalai Lama, the exiled leader of Tibet who is revered as a spiritual teacher, is at the center of a scientific controversy. He has been an enthusiastic collaborator in research on whether the intense meditation practiced by Buddhist monks can train the brain to generate compassion and positive thoughts. Next month in Washington, the Dalai Lama is scheduled to speak about the research at the annual meeting of the Society for Neuroscience. But 544 brain researchers have signed a petition urging the society to cancel the lecture, because, according to the petition, "it will highlight a subject with largely unsubstantiated claims and compromised scientific rigor and objectivity." Defenders of the Dalai Lama's appearance say that the motivation of many protesters is political, because many are Chinese or of Chinese descent. The Dalai Lama fled Tibet in 1959 after the Chinese crushed a Tibetan bid for independence. But many scientists who signed the petition say they did so because they believe that the field of neuroscience risks losing credibility if it ventures too recklessly into spiritual matters. Copyright 2005 The New York Times Company

Keyword: Miscellaneous
Link ID: 8043 - Posted: 10.19.2005

By DAVID WILLIAMSON CHAPEL HILL -- In a new study of cichlid fish descended from others caught in East Africa’s Lake Tanganika, scientists have made some surprising observations about how those animals respond to changes in their environments known as "social opportunities." Dr. Sabrina S. Burmeister, assistant professor of biology at the University of North Carolina at Chapel Hill’s College of Arts and Sciences, and colleagues found that subordinate male fish underwent a radical and rapid transformation when more dominant males were removed. "When we took dominant cichlid males from an experimental tank, subordinate males started becoming dominant themselves in as few as two minutes," Burmeister said. "Their colors -- blue and yellow -- got much brighter, a black stripe we call an eye bar appeared near their eyes, and they became much more aggressive than they were before. The remaining males also quickly paid a lot more attention to females because for the first time, they had an opportunity to reproduce." No one had any idea before that perceived changes in their social status could begin altering animals’ behavior and appearance so quickly, she said. Previous studies had shown the changes took as long as a week and were associated with increased fertility.

Keyword: Sexual Behavior; Aggression
Link ID: 8042 - Posted: 06.24.2010

Babies should get their Z's on their backs, most pediatricians advise parents. Beyond that, preventing Sudden Infant Death Syndrome, or SIDS — the number one cause of death in children under the age of one — has remained a mystery that researchers believe they may have finally cracked. Nino Ramirez, a neuroscientist at the University of Chicago, says that after nearly ten years spent unraveling the secrets of mouse nerve cells called pacemaker neurons he may have found the missing link that explains why some babies fall to SIDS. Ramirez and his team differentiated between two types of pacemaker cells active in the mouse brainstem that appear to control breathing — one group depends on calcium channels to operate and the other on sodium channels regulated by serotonin, a brain chemical known to influence mood. The latter held particular interest for Ramirez since prior research showed that babies who died of SIDS had serotonin deficits in brain areas that controlled breathing. "The idea with the serotonin is as follows," he explains. "It's present within the nervous system and these nerve cells are sitting in a soup of this serotonin. They need this…in order to generate this intrinsic ability to burst." That bursting triggers the respiratory system to gasp, which resets breathing. © ScienCentral, 2000-2005.

Keyword: Sleep
Link ID: 8041 - Posted: 06.24.2010

Atypical antipsychotic drugs seem to confer a small increased risk for death when used in people with dementia, concludes a team of researchers from the Keck School of Medicine of the University of Southern California in a meta-analysis of 15 clinical trials published in the October 19 issue of the Journal of the American Medical Association. Despite this risk, says Lon Schneider, M.D., professor of psychiatry, neurology, and gerontology at the Keck School and the USC Andrus School of Gerontology, physicians, families and patients need to keep in mind that psychosis itself is a very serious issue in dementia. "Aggression, hallucinations and delusions in dementia patients can also shorten a patient's life, and result in poor care and rapid deterioration," Schneider says. "It's a difficult problem with no easy answers." Led by Schneider, the USC researchers analyzed the results of the 15 trials--nine of which are unpublished--to determine whether there was a correlation between the use of these second-generation drugs (the atypical antipsychotics) and an increased risk for death.

Keyword: Alzheimers; Schizophrenia
Link ID: 8040 - Posted: 10.19.2005

Roxanne Khamsi Patients who suffer a stroke could get their movement and feeling back with the helping hand of magnetic pulses fired at their brains, according to new research. The experimental technique, called repetitive transcranial magnetic stimulation (rTMS), involves placing an electromagnetic coil above the scalp and releasing magnetic pulses that pass through the skull. The alternating magnetic fields cause ionic compounds inside nerve cells to flow, affecting brain activity. Over the past decade, this procedure has been used in everything from helping with brain imaging studies to treating depression, sometimes by apparently suppressing brain activity. But its full effects still aren't understood. Hubert Dinse of the Ruhr University in Bochum, Germany and his colleagues were investigating the effects of rTMS on motor activity. Experts had previously shown that magnetic pulses aimed at particular parts of the brain can cause certain muscle groups, such as those in the hand, to twitch. So Dinse and colleagues used very strong, single magnetic pulses to try and locate the motor region of the brain associated with the right index finger in 33 healthy participants. ©2005 Nature Publishing Group

Keyword: Stroke
Link ID: 8039 - Posted: 06.24.2010

No matter how trendy, all tobacco products including cigarettes, cigars, even the latest “in” smokes called bidis, come with a high price. Long-term smoking can lead to fatal heart attacks, strokes, emphysema, and cancer. Yet in the face of these negative consequences, a 2003 government survey estimated that nearly 71 million Americans had used some type of tobacco product in the past month. Many users are addicted. They have lost control over their use of tobacco and find it extremely dificult to stop smoking on their own. Nearly 35 million smokers make a serious attempt to quit each year, according to the National Institute on Drug Abuse. Unfortunately less than 7 percent who try to quit on their own remain tobacco-free more than a year. Most return to smoking within a few days. In the past, little could be done to help keep tobacco users from smoking except for counseling programs, which can be costly and do not always work. Thanks, however, to discoveries on the chemistry of tobacco's effects, some biology-based treatments are now available and even more help is on the way. The research is leading to an increased understanding of tobacco addiction and a wider range of treatment options for individuals hooked on cigarettes or other tobacco products. © 2005 Society for Neuroscience

Keyword: Drug Abuse
Link ID: 8038 - Posted: 06.24.2010

By Carl Zimmer In the past, most of the big news about human evolution came from remote dig sites in places like Africa or Indonesia. In the future, the big news will come from familiar sites closer to home: hospitals. That’s because hospitals are equipped with powerful new scanning machines primarily used to identify tumors, ballooning blood vessels, bone fractures, and a wide range of disorders in people. Those same scanners also make it possible for paleoanthropologists to look inside the fossils of ancient hominids and see things that until now have been shrouded in mystery. Take brains, for example. The evolution of the human brain is one of the most important questions in the story of our origins. But when our ancestors died, their brains quickly rotted away. Fossilized skulls offer the only clues. Until recently, if a team of researchers found an intact braincase, they were limited in what they could learn unless they cut the fossil open. Because hominid skulls are rare, few would dare take such a radical step. Now paleoanthropologists can put a hominid skull in a computed-tomography, or CT, scanner and create a virtual skull that they can split apart any way they want. If they remove that digital skull altogether, they leave behind the outlines of a virtual brain. In 2005 a virtual brain of the one known skull of Homo floresiensis—the three-foot-tall hominid discovered on the Indonesian island of Flores—provided evidence in the ongoing debate about whether the creature represents a separate species or was a human pygmy with a birth defect. The size and shape of the virtual brain lends credence to the separate species theory. Moreover, the brain was not just a simpler version of a human brain. Some regions were smaller than ours, but others were unusually large for such a small hominid, hinting that Homo floresiensis might have been capable of abstract thought and could make complicated plans. © 2005 The Walt Disney Company.

Keyword: Evolution
Link ID: 8037 - Posted: 06.24.2010

Australia has more things that will kill you than anywhere else. . . . This is a country where even the fluffiest of caterpillars can lay you out with a toxic nip, where seashells will not just sting you but actually sometimes go for you. . . . It’s a tough place. —Bill Bryson, In a Sunburned Country Raised, as you probably were, on film or video footage of drowsy koalas hugging eucalyptus trees, or kangaroos bouncing happily around the outback, you might wonder just what country Bryson is talking about. But consider the unassuming cone shell—just the kind of malicious mollusk that will “actually sometimes go for you.” The cone shell is a marine snail that lives in tropical regions worldwide, including the waters around northeastern Australia’s Great Barrier Reef. The snail aggressively reaches out to sting prey or would-be predators, injecting toxins that are among the most powerful in the animal kingdom. Even a diminutive member of the genus Conus can carry enough venom to kill a dozen people; a single careless encounter can bring death in less than thirty minutes. What’s more, the radula, a harpoonlike stinger that delivers the venom, can strike with enough speed and force to pierce a diver’s wetsuit. There is almost no pain associated with a cone-shell sting, because the venom contains a strong analgesic. That’s the good news. The bad news is that the toxin is a nerve agent for which there is no known antidote. © Natural History Magazine, Inc., 2005

Keyword: Neurotoxins
Link ID: 8036 - Posted: 06.24.2010