Some mutant flies can get by on 30% less sleep than their normal counterparts, thanks to a single mutation in one gene. The finding is important because it suggests the amount of sleep needed may be largely controlled by one gene, which may shed light on human sleep needs, says Chiara Cirelli at the University of Wisconsin-Madison, US. “This isn’t some obscure fly gene - there’s a homologue in mammals and humans.” Surprisingly, sleep in the common fruit fly - Drosophila melanogaster - has many similarities with mammalian sleep, including sleep-deprivation leading to impaired performance. Cirelli’s group has been painstakingly testing how mutations on each of 14,000 fly genes might affect slumber. They discovered that flies with one particular gene variant, dubbed “minisleep”, needed only 3 or 4 hours’ rest per day, compared to 10 to 12 hours for a normal fly. Yet, despite the lack of sleep, “minisleepers” showed no signs of impairment. They also coped better with sleep deprivation - the escape responses of minisleepers remained almost as quick after 24 hours without sleep, while the responses of normal flies flagged. © Copyright Reed Business Information Ltd.

Keyword: Sleep; Genes & Behavior
Link ID: 7262 - Posted: 06.24.2010

By ANAHAD O'CONNOR THE FACTS Is it safe to use deodorant again? About 20 years ago, scientists noticed that the brains of people with Alzheimer's disease had high levels of aluminum, leading many people to discard their pots and pans and shun almost anything that contained the metal - including antiperspirants. Today, the rumor lives on, but studies have found that there is probably no reason to sweat it. While no one disputes that aluminum can be toxic, the metal is so ubiquitous that some exposure is inevitable, and many scientists doubt that the trace amounts in antiperspirants pose any danger. Of all the studies that examined the rumor, at least one, in 1990, suggested a possible link. But the study, which compared the habits of 130 patients with the disease to those of a group of healthy subjects, had a serious flaw: It relied on surrogates to answer for the Alzheimer's patients. More rigorous studies have challenged the aluminum hypothesis. The most recent, published in 2002, followed 4,615 people for several years and found no increased risk of the disease in people who used antiperspirants or antacids, another common source of the metal. Copyright 2005 The New York Times Company

Keyword: Alzheimers
Link ID: 7261 - Posted: 04.27.2005

By ANDREW POLLACK Two participants in a discontinued clinical drug trial have sued Amgen, demanding that it resume giving them an experimental treatment for Parkinson's disease that they say helped them immensely but that the company says is ineffective and potentially dangerous. In their lawsuit, filed yesterday in Federal District Court in Manhattan, the plaintiffs say Amgen "treated the patients as mere guinea pigs, as material to be discarded," and had violated a legal and moral obligation to continue to supply the drug. A spokeswoman for Amgen said that the company had only started to review the complaint but typically would not comment on litigation. The lawsuit is the latest step in a conflict that has raised questions about the obligations of drug companies to participants in clinical trials. Last year, Amgen said that a clinical trial showed that the drug - glial cell line-derived neurotrophic factor, or G.D.N.F. - was not significantly better than a placebo. It also said that some monkeys given high doses had developed brain damage. So Amgen stopped giving the drug to about four dozen people in the trials. Copyright 2005 The New York Times Company

Keyword: Parkinsons
Link ID: 7260 - Posted: 04.27.2005

THE SINGULARITY: In futurology, a technological singularity is a predicted point in the development of a civilisation at which technological progress accelerates beyond the ability of present-day humans to fully comprehend or predict. The singularity can more specifically refer to the advent of smarter-than-human intelligence, and the cascading technological progress assumed to follow. Wikipedia - the online encyclopedia CLEVER computers are everywhere. From robotic lawnmowers to intelligent lighting, washing machines and even car engines that self-diagnose faults, there's a silicon brain in just about every modern device you can think of. But can you honestly call any machine intelligent in a meaningful sense of the word? One rainy afternoon last February I decided to find out. I switched on the computer in my study, and logged on to www.intellibuddy.com, home to one of the leading artificial intelligences on the planet, to see what the state-of-the-art has to offer. Intellibuddy: Hi, I'm Intellibuddy! Nice to meet you. JM: I'm writing an article about artificial intelligence. Intellibuddy: Will you include me in your essay? JM: I will if you can persuade me you really are intelligent. Intellibuddy: Would you recommend this action to a friend? © Copyright Reed Business Information Ltd.

Keyword: Intelligence; Robotics
Link ID: 7259 - Posted: 06.24.2010

Researchers have long known that mercury increases mortality and decreases fertility in fish, but the underlying metabolic processes are still unknown. New research posted on the ES&T Research ASAP website (es0483490) helps uncover some of the mystery by examining which genes respond when fish are fed methylmercury (MeHg). Although multiple genes turn on in the muscle and liver to help store and detoxify the metal, the brain appears unresponsive and accumulates high levels of mercury. This leads researchers to believe that neural tissue might be unable to defend itself against this toxic compound. The brains of zebrafish fail to mount a defense against methylmercury. "It was a big surprise when we found that genes in the neural system were not responding," says study author Jean-Paul Bourdineaud, a professor of biochemistry at the University of Bordeaux (France). Previous research has shown that mercury can cause lesions in the brain, and a recent study found that MeHg can decrease the density of neurotransmitters in otters that consume diets heavy in fish contaminated with MeHg. (Environ. Sci. Technol. 2005, 39, 218A) The zebra fish in the study were fed diets that contain MeHg at concentrations similar to those found in wild fish (Environ. Sci. Technol. 2002, 36, 877–883). Thirteen different genes were then tested in liver, muscle, and brain tissue. These genes encode for proteins known to be involved in different functions such as antioxidant defense, metal chelation, DNA repair, and cell death. "Testing this range of genes gives us a toxicological survey of mercury's effects," says Bourdineaud. Copyright © 2005 American Chemical Society

Keyword: Neurotoxins
Link ID: 7258 - Posted: 06.24.2010

Moderate alcohol consumption over a relatively long period of time can enhance the formation of new nerve cells in the adult brain. The new cells could prove important in the development of alcohol dependency and other long-term effects of alcohol on the brain. The findings are published by Karolinska Institutet. The study, which was carried out on mice, examined alcohol consumption corresponding to that found in normal social situations. The results show that moderate drinking enhances the formation of new cells in the adult brain. The cells survive and develop into nerve cells in the normal manner. No increase in neuronal atrophy, however, could be demonstrated. It is generally accepted these days that new nerve cells are continually being formed in the adult brain. One suggestion is that these new neurons could be important for memory and learning. The number of new cells formed is governed by a number of factors such as stress, depression, physical activity and antidepressants. “We believe that the increased production of new nerve cells during moderate alcohol consumption can be important for the development of alcohol addiction and other long-term effects of alcohol on the brain,” says associate professor Stefan Brené. “It is also possible that it is the ataractic effect of moderate alcohol consumption that leads to the formation of new brain cells, much in the same way as with antidepressive drugs.” © Karolinska Institutet,

Keyword: Drug Abuse; Neurogenesis
Link ID: 7257 - Posted: 06.24.2010

Physical activity appears to inhibit Alzheimer's-like brain changes in mice, slowing the development of a key feature of the disease, according to a new study. The research demonstrated that long-term physical activity enhanced the learning ability of mice and decreased the level of plaque-forming beta-amyloid protein fragments--a hallmark characteristic of Alzheimer's disease (AD)--in their brains. A number of population-based studies suggest that lifestyle interventions may help to slow the onset and progression of AD. Because of these studies, scientists are seeking to find out if and how physically or cognitively stimulating activity might delay the onset and progression of Alzheimer's disease. In this study, scientists have now shown in an animal model system that one simple behavioral intervention--exercise--could delay, or even prevent, development of AD-like pathology by decreasing beta-amyloid levels. Results of this study, conducted by Paul A. Adlard, Ph.D., Carl W. Cotman, Ph.D., and colleagues at the University of California, Irvine, are published in the April 27, 2005, issue of The Journal of Neuroscience. The research was funded in part by the National Institute on Aging (NIA), a component of the National Institutes of Health, U.S. Department of Health and Human Services. Additional funding was provided by the Christopher Reeve Paralysis Foundation.

Keyword: Alzheimers
Link ID: 7256 - Posted: 04.27.2005

Advertising drugs directly to patients has a “profound effect” on the way doctors prescribe, finds a new study in which actors posed as patients. Drug companies have poured billions of dollars into direct-to-consumer (DTC) advertising in the US since the rules governing mass media advertising for prescription drugs were relaxed in 1997. Other countries - such as the UK, for example - do not permit advertising directly to patients. But critics charge that DTC advertising can lead to over-prescribing which might be potentially harmful, while proponents say that giving patients knowledge about drugs can avert the under-use of effective treatments. Now a study by US researchers shows that actors consulting doctors and mentioning a particular antidepressant drug advertised on television are much more likely to get that prescription than if they do not request any medication. “Our study supplies direct experimental evidence that DTC advertisement-driven requests, along with general requests, dramatically boost prescribing,” writes the team, led by Richard Kravitz at the University of California, Davis, US. The researchers acknowledge that these requests can prevent the initial under-treatment of major depression. “But DTC advertising is a two-edged sword, driving requests that seem to be especially effective at encouraging prescribing when drugs may not be needed,” Kravitz told New Scientist. © Copyright Reed Business Information Ltd.

Keyword: Depression
Link ID: 7255 - Posted: 06.24.2010

US scientists believe they could use brain stem cells to cure diabetes. Although the work is not yet ready to be tested on human patients, results in animals have been promising, say the Stanford University researchers. They were able to coax the immature brain cells to develop into the insulin-producing islet cells that are lacking in diabetes. Eventually, these could be used for curative transplants, the scientists told the journal PLoS Medicine. Scientists have already been looking at using stem cells taken from embryos to treat diabetes. These are primitive "master" cells that can be programmed to become many kinds of tissue. However, there have been concerns that these cells can turn cancerous, are difficult to work with in the laboratory and raise ethical dilemmas. Dr Seung Kim and colleagues looked at whether adult stem cells taken from the brain might work just as well and avoid some of these issues. Dr Kim said: "When you look at islet cells you realise that they resemble neurons." In some insects, such as fruit flies, the cells that produce insulin and regulate blood sugar are also neurons. (C)BBC

Keyword: Stem Cells; Obesity
Link ID: 7254 - Posted: 04.26.2005

By CHARLES BARBER It often occurs to me, having spent most of the last decade working in shelters for the homeless mentally ill, that I am not where I am supposed to be. I went to all the right schools - Andover, Harvard, Columbia - and was on the fast track for a far more bourgeois and lucrative career, like being a doctor or lawyer. Instead, I spend my days counseling people with schizophrenia, bipolar disorder and major depression in dingy shelters. My clients tell me harrowing stories of AIDS and heroin, of crack and methadone and sexual abuse, of the voices that plague them. When I read in my college alumni magazine about the activities of my classmates (the second and third houses, the six-figure donations), I often feel a brief pang of regret about my vocational choice. But it quickly dissipates. The truth is, I am exactly where I'm supposed to be. When I was a freshman at Harvard, I was quite suddenly overwhelmed by a steady assault of unwanted, irrational and deeply painful thoughts and ideas. While I'd had brief previews of such mental compulsions as a child and adolescent - having to wear a red shirt to school the next day or horrible things would happen, for example - I had always been able to push them aside. Copyright 2005 The New York Times Company

Keyword: OCD - Obsessive Compulsive Disorder; Schizophrenia
Link ID: 7253 - Posted: 04.26.2005

Using underwater field observations in conjunction with behavioral experiments, researchers have discovered that a small crustacean, the yellow-beaked cleaner shrimp, performs a specialized dance that affects the behavior of large, predatory client fish. This signaling represents shrimp-to-fish communication that allows both hungry cleaner shrimp and parasite-laden client fish to benefit from a non-predatory, "cleaning" interaction. The cleaner-client relationship between the shrimp and the fish fulfills many criteria of an economic market, and in this context the shrimp's signals essentially represent "advertising." The work is reported by Justine Becker and colleagues at the University of Queensland. When unrelated animals cooperate, signals may be used by individuals to avoid potential conflicts. For example, during animal cleaning interactions, which involve a cleaner that removes parasites and other material from the body surfaces of cooperating individuals (known as clients), conflict may arise over the timing and duration of an interaction, over what the cleaner should feed on, or even over the temptation of some clients to eat the cleaner. Marine cleaning interactions are well known for highly stereotyped behaviors that most likely serve as signals.

Keyword: Evolution
Link ID: 7252 - Posted: 04.26.2005

12-year-old Nathan Van Vleck of Pittsford died after a nearly lifelong fight with an exceedingly rare inherited disease known as vanishing white matter (VWM) disease. As Nathan's illness progressed, the family discussed how it might help other families and patients coping with VWM, and the family decided to allow the study of some of Nathan's brain cells for research purposes. Immediately upon his death in the hospital, a team of neuropathologists and neurobiologists worked through the night to isolate some of Nathan's brain cells, which were then grown and studied in the laboratory. The outcome was an unprecedented in-depth look at the brain cells of a VWM patient. The investigation not only yielded important knowledge about how the disease affects the brain, but it also marks one of the first times that scientists have been able to isolate neural stem cells from a patient and use them to learn what is going wrong in the brain of a patient with a complex neurological disease. The team of scientists from the University of Rochester Medical Center reported its results in the March issue of the prestigious research journal Nature Medicine. VWM targets cells that make up part of the brain's white matter, turning the normally strong and durable substance into a yellowish, gelatin-like material. While we hear a great deal about the importance of our "gray matter," a term that refers to crucial brain cells known as neurons, the brain's white matter is also vital to our health. Our white matter is mostly made up of glial cells that insulate the connections between neurons. In VWM, as the white matter gradually disappears, a child typically has trouble talking and walking. As the disease progresses over several years the child has seizures, goes into a coma and often dies before reaching teen-age years. Currently there is no treatment.

Keyword: Stem Cells; Glia
Link ID: 7251 - Posted: 04.26.2005

A natural, non-toxic byproduct of glucose may prevent brain cell death and cognitive impairment in diabetics following an episode of severely low blood sugar, according to researchers at the San Francisco VA Medical Center (SFVAMC). In research studies with rats, senior investigator Raymond A. Swanson, MD, and lead author Sang Won Suh, PhD, demonstrated the effectiveness of pyruvate, a naturally-occurring byproduct of glucose, when administered along with glucose after 30 minutes of diabetic coma. The therapy prevented brain damage and subsequent memory and learning impairment far better than treatment with glucose alone. The study findings, appearing in the May 1, 2005 issue of Diabetes, have direct implications for the treatment of diabetic patients in hypoglycemic coma, according to the researchers. Glucose is a form of sugar that serves as the body's primary fuel. People with diabetes lack the ability to make insulin, the primary enzyme that metabolizes glucose and regulates its levels in the blood, and must inject insulin to make up for this lack. Abnormally low blood glucose is called hypoglycemia; severe hypoglycemia can cause coma. "It's estimated that between 2 and 15 percent of people with diabetes will have at least one episode of diabetic coma resulting from severe hypoglycemia," says Swanson, chief of the Neurology and Rehabilitation Service at SFVAMC and professor of neurology at UCSF.

Keyword: Obesity
Link ID: 7250 - Posted: 04.26.2005

By Jennifer Viegas, Discovery News — "Live fast, die young" holds true for the coral-reef pygmy goby Eviota sigillata, which has just been identified as the shortest-living vertebrate. With a maximum lifespan of 59 days, the tiny goby won the dubious title over an African fish called Nothobranchius furzeri that dies of old age after two and one half months of life. From birth to death, the new record holder lives a frantic existence in order to keep its species from going extinct. One reason is that the fish are tempting treats for predators. “ I'd like to drive home that we really know very little about the life histories, life cycles, and life styles of coral reef fishes, and that the potential of these to uncover more surprises in biology and evolution are very high. ” "These pygmy gobies are tiny (about a half-inch long) and so just about anything larger and carnivorous will take them," said lead researcher Martial Depczynski of the Center for Coral Reef Biodiversity at James Cook University in Queensland, Australia. "Predators might include dotty backs, cods, lizardfish, coral trout, moray eels, cardinalfishes, probably all take them. I call them the fun size 'Mars bars' of the reef. Little protein snacks!" Copyright © 2005 Discovery Communications Inc.

Keyword: Sexual Behavior
Link ID: 7249 - Posted: 06.24.2010

It is possible to read someone’s mind by remotely measuring their brain activity, researchers have shown. The technique can even extract information from subjects that they are not aware of themselves. So far, it has only been used to identify visual patterns a subject can see or has chosen to focus on. But the researchers speculate the approach might be extended to probe a person’s awareness, focus of attention, memory and movement intention. In the meantime, it could help doctors work out if patients apparently in a coma are actually conscious. Scientists have already trained monkeys to move a robotic arm with the power of thought and to recreate scenes moving in front of cats by recording information directly from the feline’s neurons (New Scientist print edition, 2 October 1999). But these processes involve implanting electrodes into their brains to hook them up to a computer. Now Yukiyasu Kamitani, at ATR Computational Neuroscience Laboratories in Kyoto, Japan, and Frank Tong at Princeton University in New Jersey, US, have achieved similar “mind reading” feats remotely using functional MRI scanning.

Keyword: Brain imaging
Link ID: 7248 - Posted: 06.24.2010

By GINA KOLATA IT turns out that the Duchess of Windsor was, at best, only half right when she said a woman couldn't be too rich or too thin. In fact, researchers from the Centers for Disease Control and Prevention and the National Cancer Institute, in a paper about body weight and health risks published last week, concluded that the very thin run about the same risk of early death as the very fat. Their study showed that 33,000 deaths a year could be avoided if the thinnest 2 percent of Americans were of normal weight. That result was a shock; scientists thought they had proved that thin was best, at least for healthy animals. And it was widely held that eating one-third less than the recommended amount for any individual could extend life. Almost as intriguing as the study's result is the fact that no one can explain it. Were the thin people in the study, with a body mass index below 18.5 (a 5-foot-3 woman weighing 104 pounds, for example) simply very ill, unable to eat? Not likely, said Dr. Katherine Flegal, a statistician at the National Center for Health Statistics and the paper's lead author. She and her colleagues looked at thin people whose weight was stable for at least three years, for at least five years and for at least 10 years. The effect persisted. They looked at thin smokers and thin nonsmokers. The effect remained. Copyright 2005 The New York Times Company

Keyword: Obesity
Link ID: 7247 - Posted: 04.25.2005

By Larry Cahill On a gray day in mid-January, Lawrence Summers, the president of Harvard University, suggested that innate differences in the build of the male and female brain might be one factor underlying the relative scarcity of women in science. His remarks reignited a debate that has been smoldering for a century, ever since some scientists sizing up the brains of both sexes began using their main finding--that female brains tend to be smaller--to bolster the view that women are intellectually inferior to men. To date, no one has uncovered any evidence that anatomical disparities might render women incapable of achieving academic distinction in math, physics or engineering. And the brains of men and women have been shown to be quite clearly similar in many ways. Nevertheless, over the past decade investigators have documented an astonishing array of structural, chemical and functional variations in the brains of males and females. These inequities are not just interesting idiosyncrasies that might explain why more men than women enjoy the Three Stooges. They raise the possibility that we might need to develop sex-specific treatments for a host of conditions, including depression, addiction, schizophrenia and post-traumatic stress disorder (PTSD). Furthermore, the differences imply that researchers exploring the structure and function of the brain must take into account the sex of their subjects when analyzing their data--and include both women and men in future studies or risk obtaining misleading results. © 1996-2005 Scientific American, Inc.

Keyword: Sexual Behavior
Link ID: 7246 - Posted: 06.24.2010

Of the super powers one might like to have, mind-reading would likely land near the top of the list for many people. Now two papers published this week by Nature Neuroscience show how scientists are inching toward this goal. Magnetic resonance imaging (MRI) scans of people's brains, researchers report, can reveal what types of images they have recently seen. Yukiyasu Kamitani of ATR Computational Neuroscience Laboratories in Kyoto, Japan, and Frank Tong of Princeton University showed subjects one of eight visual stimuli--images with stripes aligned in various orientations. They determined that the MRI data collected while the volunteers were gazing at the images showed slight differences depending on what picture they viewed. The scientists wrote a computer program that recognized the patterns and found that they could successfully predict what images subjects saw. What is more, when a volunteer was shown two sets of stripes simultaneously--but told to pay attention to just one--the team could tell which set the subject was concentrating on. In the second experiment, John-Dylan Haynes and Geraint Rees of University College London showed volunteers two images in quick succession, with the first flashing so quickly that the subjects couldn't clearly identify it. But by analyzing their brain activity, the scientists successfully identified which image had been shown, even when the subjects themselves didn't remember seeing it. © 1996-2005 Scientific American, Inc.

Keyword: Brain imaging
Link ID: 7245 - Posted: 06.24.2010

PET scans and cognitive tests have suggested that Alzheimer's disease patients with genetically modified tissue inserted directly into their brains show a reduction in the rate of cognitive decline and increased metabolic activity in the brain, according to a study published in the April 24, 2005 online issue of the journal Nature Medicine by researchers at the University of California, San Diego (UCSD) School of Medicine. PET scans demonstrated an increase in the brain's use of glucose, an indication of increased brain activity, while mental-status tests showed a slowing of the patients' rate of cognitive decline was reduced by 36 to 51 percent. In addition, researchers examined the brain tissue of a study participant who had died and found robust growth of extensions from the dying cholinergic cells near the site of growth factor gene delivery. Cholinergic neuron loss is a cardinal feature of Alzheimer's disease, a progressive brain disorder affecting memory, learning, attention and other cognitive processes. "If validated in further clinical trials, this would represent a substantially more effective therapy than current treatments for Alzheimer's disease," said Mark Tuszynski, M.D., Ph.D., UCSD professor of neurosciences, neurologist with the VA San Diego Healthcare System, and the study's principal investigator. "This would also represent the first therapy for a human neurological disease that acts by preventing cell death."

Keyword: Alzheimers
Link ID: 7244 - Posted: 04.25.2005

A broad retrospective review of the effects of coronary artery bypass grafting (CABG) on memory and other brain functions concludes that, while there may be transient short-term effects, the procedure itself probably does not cause late or permanent neurological effects. In an article published online April 25, 2005, in the Annals of Neurology (www.interscience.wiley.com/journal/ana), the authors argue that the late cognitive declines seen in some long-term studies are likely associated with progression of underlying conditions such as cerebrovascular disease rather than the surgery itself. "We think that there are short-term cognitive changes after CABG in a subset of patients, but absent a frank stroke, these changes are generally mild and transient," said author Ola Selnes, Ph.D., professor of neurology at Johns Hopkins Hospital in Baltimore, Maryland. "We believe most patients who experience cognitive decline will return to their baseline by three months or sooner." The exceptions, according to Selnes, might include older patients and those with risk factors for cerebrovascular disease or a history of stroke. In their review article, Selnes and co-author Guy M. McKhann, M.D., also of Johns Hopkins, surveyed the published studies on cognitive changes following CABG. Confusing the issue, they point out, is the variability in the way this question has been approached.

Keyword: Miscellaneous
Link ID: 7243 - Posted: 04.25.2005