Katie Greene Researchers have now shown how a trio of proteins controls whether an embryonic stem cell takes an irreversible step toward developing into specific tissues or retains its raw potential to become a blood cell, bone cell, brain cell, or any other kind of cell. Stem cells' unique capacity to develop into any type of cell—a property known as pluripotency—underlies their medical promise. Researchers argue that this trait could someday lead, for example, to lab-grown tissue and organs that would be useful for transplants. The scientists set out to determine what genes define a stem cell. "We thought if we could uncover this network of genes, then we could see how pluripotency is established," says Laurie A. Boyer of the Whitehead Institute in Cambridge, Mass. And with knowledge of the mechanics behind pluripotency, she says, scientists might learn to reprogram a mature cell so that it, too, could have the pluripotency of a stem cell. Boyer and her collaborators investigated three proteins known to play defining roles in keeping stem cells from developing into a specific cell type. The proteins, dubbed Oct4, Sox2, and Nanog, are classified as transcription factors. As such, they bind to specific genes and regulate the genes' activities. Scientists didn't know how these three transcription factors maintain stem cell pluripotency. ©2005 Science Service.

Keyword: Stem Cells
Link ID: 7910 - Posted: 06.24.2010

Boston, MA-An international team of 53 researchers has offered the most convincing evidence so far linking bipolar disorder, also known as manic depression, to two chromosomal regions in the human genome. The finding gives scientists refined targets for further gene studies. "Even though bipolar disorder affects millions of people around the world-sometimes throughout their lifetimes-what we understand to be biologically relevant at the genetic level is not terribly characterized," said Matthew McQueen, lead author and postdoctoral fellow in the Department of Epidemiology at the Harvard School of Public Health (HSPH). "This research can help focus the field to identify viable candidate genes." The study will appear in the October issue of the American Journal of Human Genetics and is available now in the journal's electronic edition online at http://www.journals.uchicago.edu/AJHG/journal/contents/v77n4.html. More than two million American adults have bipolar disorder, according to the National Institute of Mental Health. Patients typically experience dramatic mood swings from episodes of euphoria and high energy to feelings of intense sadness, fatigue, and even suicide. Psychiatrists have identified two primary forms of the illness: bipolar I disorder, which is the classic form of recurring mania and depression, and bipolar II disorder, which has less severe episodes of mania. Treatment often includes medication.

Keyword: Genes & Behavior; Schizophrenia
Link ID: 7909 - Posted: 09.17.2005

A novel chemical compound that blocks memory-related drug cravings has the potential to be the basis of new therapies to aid drug-addiction recovery efforts, UC Irvine neurobiologists have found. Because exposure to people, places and objects previously associated with a drug habit can trigger overwhelming memory-based cravings, many former drug users often relapse into drug-taking behavior. But a study led by John F. Marshall, a researcher in UCI’s Center for the Neurobiology of Learning and Memory, shows that memory for places associated with cocaine use can be strikingly altered by inactivating a specific protein called ERK (extracellular signal-regulated kinase) in the brains of animals. Especially significant is the finding that administering the inactivator compound immediately after recall of the cocaine-associated places also continued to blur memories of those places weeks later. This research provides novel insights into the brain mechanisms underlying relapse and suggests a new strategy for developing addiction treatments. Study results appear in the Sept. 15 issue of Neuron. “Our findings suggest that memories responsible for relapse in drug addicts may be similarly disrupted by a therapeutic agent targeting ERK or related proteins,” Marshall said. “This work, however, is a first step toward subsequent efforts that can produce effective drug-addiction therapies.” Copyright 2002-2005 UC Regents

Keyword: Drug Abuse; Learning & Memory
Link ID: 7908 - Posted: 06.24.2010

A team of researchers led by the University of Toronto has charted how and where a painful event becomes permanently etched in the brain – a discovery that has implications for pain-related emotional disorders such as anxiety and post-traumatic stress. U of T physiology professor Min Zhuo and his colleagues Professor Bong-Kiun Kaang of Seoul National University in South Korea, and Professor Bao-Ming Li of Fudan University in China have identified where emotional fear memory and pain begin by studying the biochemical processes in a different part of the brain. In a paper published in the Sept.15 issue of Neuron the researchers use mice to show how receptors activated in the pre-frontal cortex, the portion of the brain believed to be involved with higher intellectual functions, play a critical role in the development of fear. Previous research had pointed to activation in the hippocampus, an area buried in the forebrain that regulates emotion and memory, as the origin of fear memory. "This is critical as it changes how and where scientists thought fear was developed," says Zhuo, the EJLB-CIHR Michael Smith Chair in Neurosciences and Mental Health. "By understanding the biomolecular mechanisms behind fear, we could potentially create therapeutic ways to ease emotional pain in people. Imagine reducing the ability of distressing events, such as amputations, to be permanently imprinted in the brain."

Keyword: Emotions
Link ID: 7907 - Posted: 06.24.2010

Keeping a stiff upper lip during an emotional event can impair your memory, research suggests. Those who battled to hide their emotions paid a cognitive price and were less able to recall the upsetting episode than others, a study found. The work described in New Scientist involved more than 200 volunteers. James Gross, Stanford University, and Jane Richards, the University of Texas at Austin, published their study in the Journal of Research and Personality. They asked 57 volunteers to watch an emotive film about a surgical procedure and then asked them about how they were feeling, how much effort they put into hiding their emotions and how much they remembered about the film. The people who said they had put the most effort into hiding their emotional response to the film had the worst recall for what they had seen. The researchers then decided to test another 175 volunteers. (C)BBC

Keyword: Emotions; Learning & Memory
Link ID: 7906 - Posted: 09.15.2005

By GARDINER HARRIS The use of drugs to treat attention-deficit hyperactivity disorder in younger adults more than doubled from 2000 to 2004, and spending on the drugs in the same age bracket, 20 to 44, more than quadrupled, a major prescription management company is reporting today. The pills are also becoming increasingly popular among women. Indeed, adult women are now just as likely as men to take them, said the company, Medco Health Solutions. Among children, use by boys is nearly three times as likely as by girls. One percent of adults ages 20 to 64 now take the drugs, according to Medco, which administers pharmaceutical benefits for managed care companies. "I think this shows a clear recognition and new thinking that treatment for A.D.H.D. does not go away for many children after adolescence," said Dr. Robert S. Epstein, the company's chief medical officer. Dr. James McGough, a professor of clinical psychiatry at the University of California, Los Angeles, said more adults should probably be taking the pills. A recent study by Harvard researchers found that as many as 4 percent of adults had symptoms of the disorder, Dr. McGough noted. Of the Medco report, he said, "I think it's a good sign that this is increasingly recognized and people are getting help." Copyright 2005 The New York Times Company

Keyword: ADHD
Link ID: 7905 - Posted: 09.15.2005

Ed Owen It is "the ultimate evil" and "the most intense form of systematic cruelty in the history of humanity". Strong stuff. Yet these are not descriptions of the Holocaust or the genocides of Rwanda or Cambodia. It is how one animal rights group chooses to describe on its website the use of animals in scientific research. And far from being members of a balaclava-clad, extremist fringe, the authors of this rhetoric are from a mainstream organisation called Uncaged, which lobbies the government and works closely with many of our MPs. In the wake of the news last month that Darley Oaks Farm in Staffordshire, which bred guinea pigs for research purposes, was being forced to shut down its business, there has been a renewed focus on the militants within the animal rights lobby who use intimidation and violence to get their way. But in doing so, we must also step up effective scrutiny of the equally uncompromising arguments of those groups that do act within the law. Make no mistake, these so-called moderate organisations are as fundamental in their aims, if not in the tactics, as the hard core. I should at the outset declare an interest. My three-year-old daughter suffers from cystic fibrosis, a life-threatening inherited condition that attacks the lungs and digestive system. About one in every 2,500 babies born in the UK is affected. Our refrigerator and kitchen cupboards are full of medicines that have been developed with the help of animal research. Using these treatments, most sufferers can expect to live until their early thirties with a disease that few used to survive beyond childhood. © New Statesman 1913 - 2005

Keyword: Animal Rights
Link ID: 7904 - Posted: 06.24.2010

Previous research has shown that alcohol-use disorders (AUDs) are associated with abnormalities of the prefrontal cortex, thalamus and the cerebellar hemispheres in adults. These same brain structures are known to be actively maturing during adolescence. An examination of adolescents and young adults with AUDs has found that a smaller prefrontal cortex is associated with early-onset drinking. Results are published in the September issue of Alcoholism: Clinical & Experimental Research. "This is the first study to examine the sizes of these brain structures in adolescents and young adults," said Michael D. De Bellis, professor of psychiatry and behavioral sciences and director of the Healthy Childhood Brain Development Research Program at Duke University Medical Center, as well as corresponding author for the study. "Studies on adults with alcoholism have generally shown smaller brain sizes, but this is after many years of very heavy drinking," added Susan Tapert, associate professor of psychiatry at the University of California at San Diego. "Before this study, it really wasn't clear that adolescents, with briefer drinking histories, would show any differences in brain size. However, with nearly one in three high-school seniors binge drinking at least once per month, it is critical that we understand precisely how drinking affects the brain of these young people."

Keyword: Drug Abuse; Development of the Brain
Link ID: 7903 - Posted: 09.15.2005

For recovering addicts, the sight of drug paraphernalia and other reminders can trigger intense cravings and relapses. Now, two studies with rats demonstrate that it's possible to weaken drug-related memories by interfering with molecular signals in the brain's reward pathways. The work is a long way from the clinic, but researchers say it hints at an exciting new approach to helping addicts kick the habit. Both studies, published in the 15 September issue of Neuron, add to growing support for a process called memory reconsolidation. This controversial idea holds that each time a memory is recalled it becomes briefly vulnerable--and can be weakened by compounds that target certain genes or molecules in the brain. To find out whether drug-related memories can be weakened during recall, Jonathan Lee and colleagues at the University of Cambridge, U.K., first introduced a group of rats to the pleasures of cocaine. The animals quickly learned that a glowing light appeared each time they scored a hit. When the rats subsequently visited a different chamber, they busily pressed a lever that turned on the light, even if no cocaine was forthcoming. © 2005 by the American Association for the Advancement of Science.

Keyword: Drug Abuse; Learning & Memory
Link ID: 7902 - Posted: 06.24.2010

MADISON - In a study of adult monkeys who were exposed to moderate amounts of alcohol in utero, scientists have found that prenatal exposure to alcohol - even in small doses - has pronounced effects on the development and function later in life of the brain's dopamine system, a critical component of the central nervous system that regulates many regions of the brain. Writing in the current issue (Sept. 15, 2005) of the journal Alcoholism: Clinical and Experimental Research, a team of researchers led by Mary L. Schneider, a University of Wisconsin-Madison professor of occupational therapy and psychology, reports that when a monkey exposes her fetus to alcohol by drinking, the dopamine system of her offspring is altered. Effects on that key neural system, according to the study's results, can manifest themselves up to five years after birth, when the monkeys are fully grown. The influence of alcohol on the dopamine system, depending on the timing of exposure during gestation, varies, says Schneider, but illustrates yet another biological consequence of drinking while pregnant. "It appears that there is no safe time to drink," says the Wisconsin researcher. "And because our study looked at the effects of lower doses of alcohol than most previous studies, the results suggest there is no safe amount of alcohol that can be consumed during pregnancy. Even moderate drinking can have effects that persist to adulthood."

Keyword: Drug Abuse; Development of the Brain
Link ID: 7901 - Posted: 09.15.2005

Andreas von Bubnoff Sharing the same sexual partner with your mother or grandmother may sound odd, but female greater horseshoe bats (Rhinolophus ferrumequinum) in Britain do it all the time. This ensures that the bats in the colony are closely related to each other, says Stephen Rossiter at Queen Mary, University of London, lead author of a study appearing this week in Nature1. Researchers believe that such close family ties encourage cooperation, such as food sharing, between colony members. But although related females share mates, they manage to avoid the genetic pitfalls of inbreeding, the researchers found. Rossiter's team studied a colony of 45 female bats living in the attic of Woodchester Mansion in Gloucestershire, UK, over a period of ten years. In that time they found a much higher rate of related female bats sharing partners than expected: 11 pairs of mothers and daughters shared mates at least once, for example, along with 7 pairs of grandmothers and granddaughters. Yet amidst all this partnering, there was only one case of a female mating with her own father. How the females avoid mating with close relatives is unclear; they might use smell as a cue, Rossiter says. ©2005 Nature Publishing Group

Keyword: Sexual Behavior; Evolution
Link ID: 7900 - Posted: 06.24.2010

PORTLAND, Ore. - Some people call it "the dark time," the period between when a person is diagnosed with Parkinson's disease and when treatment with medication begins. Julie Carter, R.N., knows it all too well. The associate professor of neurology in the Oregon Health & Science University School of Medicine hosts workshops to help newly diagnosed Parkinson's patients and their families cope with the prospect of fighting a chronic, degenerative, incurable neurological disease the rest of their lives. "Some people say it's like looking through a picture window and someone comes along and shatters it," said Carter, associate director of the OHSU Parkinson Center of Oregon, which runs the workshops. "Patients are told they're not ready for medication and to come back in six months. But in these early stages, what you're really dealing with is a diagnosis. You're dealing with a fear of what the future will hold." And there is a lot that can be done to treat Parkinson's patients, in the early months and beyond. So says an article by John "Jay" G. Nutt, M.D., professor of neurology, and physiology and pharmacology, OHSU School of Medicine, and director of the Parkinson center. The article appearing in the Thursday, Sept. 8, edition of the New England Journal of Medicine outlines reliable, evidence-based strategies for general practitioners to effectively and confidently diagnose Parkinson's, and suggest ways patients and their caregivers can initially manage the disease.

Keyword: Parkinsons
Link ID: 7899 - Posted: 09.15.2005

By PETER C. BELLER Josh Bedwell was deep into his third year at Mount Sinai School of Medicine before he got up the nerve to ask a resident for permission to go home. After 7 a.m. rounds and a lunchtime class, Mr. Bedwell often found himself stuck at the hospital with nothing to do. Dr. Josh Bedwell, a former student at Mount Sinai School of Medicine, said students would often put in long hours at the hospital doing little. "You sit there until the resident is like 'Oh, you're still here? You should go home.' That gets really old," said Dr. Bedwell, 25, now a surgical intern at Beth Israel Medical Center. While sleep deprivation and long workdays are deemed rites of passage for medical students, there is growing concern among medical educators that students may be spending excessive hours in hospitals doing work of little educational value, to the detriment of their education and health. In a recent survey by the American Medical Association, one in four students said lack of sleep had put them in physical danger and one in six reported having or nearly having a car accident because of sleep deprivation. Two-thirds said fatigue might have affected their learning. As a result, medical schools and the bodies that set policy for medical education are debating whether medical students should have strict guidelines similar to those that limit the hours medical residents can work. Copyright 2005 The New York Times Company

Keyword: Sleep
Link ID: 7898 - Posted: 09.14.2005

by Julian Baggini 256pp, Granta, £14.99 Do you remember having a rather disturbed night's sleep about a month ago? That was the night I stole your brain. After landing my flying saucer in your garden, I crept into your bedroom and surgically removed your sleeping brain. I whisked it to my laboratory back on Pluto and connected it up to a supercomputer running a virtual-Earth program. This computer is currently feeding into your brain the same patterns of electrical stimulation that used to be produced by your sense organs, when you still had some. So it seems to you as though you're still on Earth. But everything you seem to observe around you, including this newspaper, is actually virtual. You've been brain-snatched. How can you tell this hasn't happened: that what you're experiencing now isn't virtual? It seems you can't. But if you can't tell whether this newspaper is real or virtual, then how can you be said to know it's real? This is a famous philosophical thought experiment. In just a few sentences, it seems to demolish something we would ordinarily take entirely for granted: our knowledge of the world around us. Thought experiments can induce an overwhelming sense of intellectual vertigo. What we thought was the firm ground beneath our feet suddenly crumbles and we're left dangling over a void. © Guardian Newspapers Limited 2005

Keyword: Miscellaneous
Link ID: 7897 - Posted: 06.24.2010

Kaley Terre Haute, Ind. Robert Heinsohn, professor of evolutionary biology at the Australian National University, explains. Males are more colorful or ornamented than females in most, but not all, bird species. Understanding this phenomenon requires a basic grasp of the evolutionary forces that shape the behavior and morphology of individuals and species. Charles Darwin developed much of the theory that helps explain this. He proposed that traits promoting survival in individuals are favored by the process of natural selection, whereas traits that help the individuals of just one sex (usually the males) compete for mates are favored by sexual selection. Sexual selection is responsible for many of the features unique to one sex in a given species. These features can be divided into two general categories: those acting as weapons that allow males to fight for access to females (antlers on deer, for example) and those acting as ornaments that attract the attention of females, such as long tails on birds. Darwin concluded that color differences between sexes in birds (also known as sexual dichromatism) result largely from female preference for bright colors in males. This general rule has received much support since Darwin's time, but other influences have also been noted. For example, females of species that are exposed to predators while incubating tend to have dull colors, although both sexes may be brightly colored in species that nest in tree hollows because the females are less visible to predators. Color can also aid individuals in recognizing members of their own species. And in species that are not good to eat, colors can provide a warning to potential predators. © 1996-2005 Scientific American, Inc.

Keyword: Sexual Behavior; Evolution
Link ID: 7896 - Posted: 06.24.2010

A new study reveals critical molecular events in the origin of fat cells. The findings are central to understanding chronic diseases, such as obesity and diabetes, as fat cells produce hormones critical for metabolic control, the researchers said. The study finds that a hormonal cocktail routinely used in the lab induces a key genetic switch in the transition from fat-cell precursors to full-blown fat, researchers at University of Michigan Life Sciences Institute report in the September Cell Metabolism. "The body needs fat cells, both as a storage depot for fuel and as cells that sense hormonal and energy status and in response, secrete hormones that maintain whole-body energy balance," said study author Alan Saltiel. "However, you don't want too many, big fat cells. It's a careful balance, and many diseases are associated with either extreme." Lipodystrophies are disorders characterized by fat deficiency, Saltiel said. While obesity and lipodystrophy represent opposite ends of the spectrum, both are characterized by other metabolic disorders, such as insulin resistance, he added.

Keyword: Obesity
Link ID: 7895 - Posted: 09.14.2005

By Larry O'Hanlon, Discovery News —Namibian elephants really know the airwaves, say researchers who have discovered that the big mammals prefer to broadcast their very low-frequency calls at exactly the times of day when the air is best for carrying sound a long way. In a three-week study that incorporated a range of meteorological equipment and an array of eight microphones, 42 percent of all elephant calls were made during the stable air period three hours after sunset. The next most popular calling time during the two hours after sunrise, also a time when the acoustics of the atmosphere are the best for carrying calls great distances. "This project was an attempt to demonstrate in the field predictions we had made with mathematical, acoustical models," said Michael Garstang of the University of Virginia. A paper co-authored by Garstang, reporting the results of the work, appears in the current issue of the journal Earth Interactions. Of about 1,300 calls recorded during the study, 94 percent fell within those two time periods, he said. © 2005 Discovery Communications Inc.

Keyword: Hearing; Animal Communication
Link ID: 7894 - Posted: 06.24.2010

By Sandra G. Boodman A few days after the terrorist attacks of 2001, mental health experts descended on New York, poised to help residents cope with a wave of psychiatric problems that never materialized. But experts in disaster psychiatry predict that the repercussions from Hurricane Katrina, a catastrophe without parallel in modern American history, are likely to be far greater and to last for years. "This is unprecedented," said New York psychiatrist Spencer Eth, who was involved in treating survivors of the World Trade Center attack, which unlike the hurricane, killed many victims at the scene and destroyed several office towers, not entire communities. "People are not going to bounce back and resume their lives and recover" at the pace seen after other disasters, Eth predicted. The previous disasters on which experts rely for lessons about how to handle the victims of mass tragedy -- plane crashes, earthquakes and hurricanes including Andrew, which struck Florida in 1992; the bombing of the Oklahoma City federal building in 1995; the attacks of Sept. 11, 2001 -- are all dwarfed by the devastation wrought by Katrina. © Copyright 1996-2005 The Washington Post Company

Keyword: Stress; Depression
Link ID: 7893 - Posted: 06.24.2010

By ANAHAD O'CONNOR THE FACTS It's 1 a.m., and you wake up to find someone you know quietly wandering around the house - eyes open but appearing dazed. Should you wake the person? Some people give credence to the adage that rousing a sleepwalker can give him a heart attack. But experts say it's highly unlikely. Dr. Ana C. Krieger, the director of the Sleep Disorders Center at New York University, said the myth probably started because of sleepwalkers' response when they're awakened. Many are confused and terrified, having no idea how they ended up in a dark closet or gliding down a hallway. "At that point, they might not even recognize relatives," Dr. Krieger said. "If this is a well-known friend or child, and the person wakes up and is saying, 'Get me out of here! Who are you?' it can be very frightening." She recommends guiding the person back to bed by an arm or elbow. Researchers are not sure what brings on sleepwalking, but it's known that it occurs during the deepest and most restful stages of sleep. As people age, the amount of time they spend in these stages decreases sharply, explaining why children are more likely to sleepwalk than adults. Copyright 2005 The New York Times Company

Keyword: Sleep
Link ID: 7892 - Posted: 09.13.2005

By JANE E. BRODY A serious dispute over vitamins should concern every woman of childbearing age who wants to protect her unborn child against a serious and sometimes fatal birth defect of the spine or brain. And not just women who are planning to become pregnant. Half of all pregnancies in this country are unplanned, so every woman who could become pregnant - including teenage girls, many of whom fail to anticipate having sex, let alone becoming pregnant - should act now to prevent these defects. The battle involves the B vitamin folic acid, which aids in the normal development of a baby's neural tube, the part that becomes the brain and spinal cord. Neural tube development takes place three to four weeks after conception, before many women know they are pregnant. And since it can take a while to build up protective blood levels of folic acid, it is necessary to have enough folic acid on board when a woman conceives and through the first three months of pregnancy for maximum protection against neural tube defects. These defects are among the most common serious birth defects. They include spina bifida, an often crippling failure of the spine and back bones to close fully, and anencephaly, a fatal failure of the brain and skull to form properly. Copyright 2005 The New York Times Company

Keyword: Development of the Brain
Link ID: 7891 - Posted: 09.13.2005