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

An elite squad of real but remote-controlled rats could soon be scouring enemy bases and sniffing out explosives for the US military. The rodents are directed using a series of brain implants, which can be operated wirelessly from a distance of several hundred metres. Now, for the first time, the researchers behind the project have demonstrated the ability to control the rodents' movements before activating their “sniffer dog” instincts. John Chapin and colleagues at the State University of New York, US, say the rats could eventually sniff out hidden weapons or act as remote video sensors for military and police forces. With colleagues from the University of Florida in Gainesville, US, they have previously shown that brain implants can be used to steer the rats over an assault course, or home in on a particular odour. But combining the two tricks is a significant step towards turning them into useful “robo-rodents”. "It's important to have them switch between behaviours," Chapin told New Scientist. "Obviously, there are a lot of very important potential applications.” The rats are remotely controlled using electrodes inserted into the medial forebrain bundle (MFB), a part of their brain associated with reward, and the somatosensory cortical area, which is linked to the right and left whiskers. © Copyright Reed Business Information Ltd

Keyword: Robotics; Chemical Senses (Smell & Taste)
Link ID: 7242 - Posted: 06.24.2010

THE way patterns of shift work are organised could be causing major health problems, according to a pair of reports commissioned by the UK government body that regulates workplace safety. The reports, prepared for the Health and Safety Executive (HSE), show that offshore oil workers adopting the most popular shift pattern have a higher risk of heart disease and diabetes. This pattern also makes workers more tired and inattentive, increasing the chance of accidents and mistakes. Chronobiologist Josephine Arendt and her team at the University of Surrey in Guildford and psychologist Andrew Smith and colleagues at Cardiff University in Wales separately studied the physiological and psychological health of a group of 45 men working on offshore oil rigs. Both teams compared the two main shift schedules operated on a two-week tour of duty. One was a simple 12-hour shift, with workers staying on night shifts or day shifts for the full two weeks. The other was a split rota of seven night shifts followed by seven day shifts. This was more popular with the workers because they were already adapted to night sleeping when they returned home. But it proved worst for their health. Urine tests from workers on the split shift revealed that levels of melatonin, the sleep-regulating hormone normally secreted at night, did not become synchronised to the new sleep times after shift changes. As well as being more tired and less attentive on the job, these unadapted workers showed signs of being at risk of long-term health effects. The men had abnormally high levels of fatty acids circulating in their blood after meals, compared with the day shift or adapted workers. This increases the risk of heart disease, diabetes and other metabolic disorders. "The swing shift is the killer," says Arendt. © Copyright Reed Business Information Ltd.

Keyword: Biological Rhythms
Link ID: 7241 - Posted: 06.24.2010

By Paul Rincon BBC News science reporter Mice have been placed in a state of near suspended animation, raising the possibility that hibernation could one day be induced in humans. If so, it might be possible to put astronauts into hibernation-like states for long-haul space flights - as often depicted in science fiction films. A US team from Seattle reports its findings in Science magazine. In this case, suspended animation means the reversible cessation of all visible life processes in an organism. The researchers from the University of Washington and the Fred Hutchinson Cancer Research Center in Seattle put the mice in a chamber filled with air laced with 80 parts per million (ppm) of hydrogen sulphide (H2S) - the malodorous gas that gives rotten eggs their stink. Hydrogen sulphide can be deadly in high concentrations. But it is also produced normally in humans and animals, and is believed to help regulate body temperature and metabolic activity. In addition to its possible use in space travel, the ability to induce a hibernation-like state could have widespread uses in medicine. Lead investigator Dr Mark Roth said this might ultimately lead to new ways of treating cancer, and preventing injury and death from insufficient blood supply to organs and tissues. During hibernation, activity in the body's cells slows to a near standstill, dramatically cutting the animal's need for oxygen. If humans could be freed from their dependence on oxygen, it could buy time for critically ill patients on organ-transplant lists and in operating rooms, said Dr Roth. "Manipulating this molecular mechanism for clinical benefit potentially could revolutionise treatment for a host of human ills related to ischaemia (deficiency of the blood supply), or damage to living tissue from lack of oxygen," he explained. But he added that any procedure in a clinical setting would likely be administered via injection rather than by getting patients to inhale a gas. (C)BBC

Keyword: Sleep; Biological Rhythms
Link ID: 7240 - Posted: 04.23.2005

Workers distracted by email and phone calls suffer a fall in IQ more than twice that found in marijuana smokers, new research has claimed. The study for computing firm Hewlett Packard warned of a rise in "infomania", with people becoming addicted to email and text messages. Researchers found 62% of people checked work messages at home or on holiday. The firm said new technology can help productivity, but users must learn to switch computers and phones off. The study, carried out at the Institute of Psychiatry, found excessive use of technology reduced workers' intelligence. Those distracted by incoming email and phone calls saw a 10-point fall in their IQ - more than twice that found in studies of the impact of smoking marijuana, said researchers. More than half of the 1,100 respondents said they always responded to an email "immediately" or as soon as possible, with 21% admitting they would interrupt a meeting to do so. (C)BBC

Keyword: Drug Abuse; Intelligence
Link ID: 7239 - Posted: 04.23.2005

Bernadette Tansey, Chronicle Staff Writer The Food and Drug Administration has asked the makers of all epilepsy drugs to re-examine their clinical trial data in response to claims that one of the medicines, Pfizer's Neurontin, boosts the risk of suicide. Word of the FDA action came in response to a petition filed last May by personal injury attorney Andrew Finkelstein, who has been urging the agency to warn doctors that the commonly prescribed drug Neurontin can lead to severe depression and suicide. Neurontin, with $2.7 billion in sales last year, has been prescribed to more than 10 million people since it was put on the market in 1994. Although it was formally approved for patients suffering from epilepsy and later for pain related to a skin disorder, it has since been prescribed for illnesses ranging from psychiatric disorders to back pain. Finkelstein bases his claims on the FDA's own records as well as 318 suicides and about 2,000 suicide attempts among families he represents. The FDA's inquiry comes as it tries to repair its image as the guardian of drug safety after a series of controversies over its response to warnings about serious side effects linked to several other blockbuster medicines. ©2005 San Francisco Chronicle

Keyword: Epilepsy; Development of the Brain
Link ID: 7238 - Posted: 06.24.2010

Researchers have found a brain mechanism that may calm you down in life or death situations and may give you a better chance at survival. The study was done in rats, but as this ScienCentral New video explains it may have important implications for people. In life or death situations, survival sometimes hangs on the threads of willpower. When British mountaineer and author of Touching the Void Joe Simpson crawled through the Peruvian Andees twenty years ago with broken bones and no food or water, death seemed certain. But he didn’t give up hope and he made it back to base camp. He told Climber Magazine he couldn’t "Just sit there." Now neuroscientists say a person’s belief in their ability to survive a life or death situation may be a function of brain circuitry. "It’s belief in control that really matters, not that you really can [survive] or not," says Steven Maier, director of the Center for Neuroscience at the University of Colorado at Boulder. By "control" Maier means having the presence of mind to handle life or death situations as opposed to just freezing or feeling helpless. (C) ScienCentral, 2000-2005.

Keyword: Stress
Link ID: 7237 - Posted: 06.24.2010

Bruce Bower A new scientific era may have dawned for light therapy, a potential depression fighter that has languished in the shadows of antidepressant medication and psychotherapy for the past 20 years. A research review commissioned by the American Psychiatric Association in Washington, D.C., concludes that in trials, daily exposure to bright light is about as effective as antidepressant drugs in quelling seasonal affective disorder (SAD), or winter depression, and other forms of depression. "I now tell my patients that light therapy is a reasonable depression treatment, even if the data base for this approach is relatively small," says psychiatrist Robert N. Golden of the University of North Carolina at Chapel Hill. Golden directed the new statistical review, which appears in the April American Journal of Psychiatry. Like many mainstream psychiatrists, Golden had been skeptical of studies reporting that depression diminishes in response to daily bright-light exposure, usually administered early in the morning for 30 minutes to 1 hour. These investigations often contain serious flaws, he says, such as few participants and no groups treated with dim lights or other placebos. Copyright ©2005 Science Service

Keyword: Depression; Biological Rhythms
Link ID: 7236 - Posted: 06.24.2010

Clues about how a suspect version of a gene may slightly increase risk for schizophrenia* are emerging from a brain imaging study by the National Institutes of Health's (NIH) National Institute of Mental Health (NIMH). The gene variant produced a telltale pattern of activity linked to production of a key brain messenger chemical. The study found that increased activity in the front of the brain predicted increases in the neurotransmitter dopamine in the middle of the brain in subjects with the suspected schizophrenia-related version of the gene. Yet, the opposite relationship held for subjects with the other of two common versions of the gene. "A tiny variation in the gene that makes the enzyme that breaks down dopamine causes a complete flipflop – not a mere difference in degree – in dopamine activity in these two brain areas," explained NIMH's Dr. Andreas Meyer-Lindenberg, who, along with Dr. Karen Berman and colleagues, reported their findings in the April 10, 2005 online edition of Nature Neuroscience. The NIMH study also for the first time confirms in living humans that activity of the front brain area, the prefrontal cortex, is regulated by dopamine production in the midbrain, which, in turn, is regulated by these two common gene variants.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 7235 - Posted: 06.24.2010

A new mouse study suggests that a brain system that controls the sleep/wake cycle might also play a role in regulating appetite and metabolism. Mice with a mutation in a gene called "Clock," which helps drive circadian rhythm, ate significantly more and gained more weight. The finding could help explain why disrupted sleep patterns-particularly when combined with a high-fat diet--are associated with excessive weight gain and the onset of metabolic syndrome in some people, according to investigators supported by the National Institutes of Health (NIH). The study, by Fred W. Turek, Ph.D., and Joseph Bass, M.D., Ph.D., of Northwestern University in Evanston, Ill., and others will be available at the Science Express website, http://www.sciencemag.org/sciencexpress/recent.shtml, on April 21, 2005. At least 40 million Americans have chronic sleep problems, and an additional 20 million experience occasional sleeping problems. As many as 47 million Americans have metabolic syndrome, a cluster of conditions shown to increase a person's risk of heart disease and stroke. The National Cholesterol Education Program defines metabolic syndrome as having at least 3 of the following risk factors: high blood pressure, high glucose (sugar) levels which can indicate risk for diabetes, high triglyceride levels, low levels of good cholesterol, and a large waist. Scientists have found that circadian rhythms (which control the sleep/wake cycle and other biological processes), hunger, and satiety are all regulated by centers within a brain structure called the hypothalamus. And previous studies in humans have suggested that disrupted sleep patterns may contribute to the development of obesity, diabetes, and metabolic syndrome.

Keyword: Sleep; Biological Rhythms
Link ID: 7234 - Posted: 04.23.2005

Jessica Ebert It seems that mice can be coaxed into a hibernation-like state by a whiff of hydrogen sulphide, the gas found in rotten eggs. The discovery could improve the preservation of organs or tissues for transplants, and could lead to more effective treatments for illnesses as diverse as cancer and stroke. Hydrogen sulphide can be deadly in high concentrations, causing burns and interfering with respiration. But it is also produced in small quantities by animals, in which it is thought to play a vital role in controlling body temperature and metabolism. Mark Roth, a biochemist at the Fred Hutchinson Cancer Research Center, Seattle, and his colleagues tried exposing mice to air laced with relatively low concentrations of the gas: within minutes, the mice seemed to fall unconscious. Their core body temperature dropped by some 20ºC, and their breathing slowed from about 120 breaths a minute to fewer than 10, the team reports in Science1. When re-exposed to clean air after six hours, the mice bounced back without any evident side-effects, says Roth. "This indicates that it's possible to decrease metabolic rate on demand," says Roth. By shutting down metabolism, the body's need for oxygen diminishes, which could "revolutionize treatment for a host of human ills", says Roth. ©2005 Nature Publishing Group

Keyword: Sleep; Stroke
Link ID: 7233 - Posted: 06.24.2010

An article in the journal Epilepsia reviewed recent data on the risks associated with continuation of medical treatment of women with epilepsy during their pregnancies. While the general consensus is that use of antiepileptic drugs is associated with increased risk for birth defects, physicians weigh this risk against that of uncontrolled epileptic seizures, which can be more harmful to the fetus than the actual drugs. Most women with active epilepsy choose to continue with drug therapy during pregnancy and have more than 90% chance to give birth to a perfectly healthy child. It remains unsolved whether risks for birth defects vary with different drugs. One drug, valproate, has been associated with a higher risk of birth defects than some others although the reasons for this have not been completely clarified. However, for some patients, valproate is the most effective medication for controlling the seizures, which must be balanced against the risk. An additional concern could be possible postnatal effects of anti-epileptic drugs to the child which do not become apparent until school age.

Keyword: Epilepsy; Development of the Brain
Link ID: 7232 - Posted: 04.23.2005

Nervous system development requires billions of neurons to migrate to the appropriate locations in the brain and grow nerve fibers (axons) that connect to other nerve cells in an intricate network. Growth cones, structures in the tips of growing axons, are responsible for steering axons in the right direction, guided by a complex set of signals from cells they encounter along the way. Some signals lure the axons to extend and grow in a particular direction; others are inhibitory, making the axon turn away or stop growing. In two papers in the April 21 Neuron, researchers from Children's Hospital Boston reveal important insights into how inhibitory cues affect the growth cone, and identify possible targets within axons that could be blocked to overcome this inhibition. Such intervention could possibly enable damaged axons to regenerate (normally impossible in a mature nervous system) and ultimately restore nerve function. It's been known that cells synthesize an inhibitory protein called ephrin, which binds to a receptor called Eph on the axon's growth cone. But how this triggers the axon to change course or stop growing has been a mystery.

Keyword: Development of the Brain
Link ID: 7231 - Posted: 04.21.2005

DALLAS – – Why people get drowsy and fall asleep, and how caffeine blocks that process, are the subjects of a new study by researchers at UT Southwestern Medical Center. When cells in a certain part of the brain become overworked, a compound in the brain kicks in, telling them to shut down. This causes people to become drowsy and fall asleep. Alter that natural process by adding coffee or tea, and the brain compound – called adenosine – is blocked, and people stay awake. These findings, available online and in the April 21 issue of the journal Neuron, offer new clues regarding the function of the brain in the body's natural sleep process, as well as potential targets for future treatments for insomnia and other sleep problems. Prolonged increased neural activity in the brain's arousal centers triggers the release of adenosine, which in turn slows down neural activity in the arousal center areas. Because the arousal centers control activity throughout the entire brain, the process expands outward and causes neural activity to slow down everywhere in the brain. "Insomnia and chronic sleep loss are very common problems," said Dr. Robert W. Greene, professor of psychiatry and senior author of the study. "In addition, all the major psychiatric disorders, including depression, schizophrenia and post-traumatic stress disorder have sleep disruption as a prominent symptom.

Keyword: Sleep
Link ID: 7230 - Posted: 06.24.2010