WINSTON-SALEM, N.C. – Using positron emission tomography (PET), researchers have established a firm connection between a particular brain chemistry trait and the tendency of an individual to abuse cocaine and possibly become addicted, suggesting potential treatment options. The research, in animals, shows a significant correlation between the number of receptors in part of the brain for the neurotransmitter dopamine – measured before cocaine use begins – and the rate at which the animal will later self-administer the drug. The research was conducted in rhesus monkeys, which are considered an excellent model of human drug users. Generally the lower the initial number of dopamine receptors, the higher the rate of cocaine use, the researchers found. The research was led by Michael A. Nader, Ph.D., professor of physiology and pharmacology at Wake Forest University School of Medicine. It was already known that cocaine abusers had lower levels of a particular dopamine receptor known as D2, in both human and animal subjects, compared to non-users. But it was not known whether that was a pre-existing trait that predisposed individuals to cocaine abuse or was a result of cocaine use. "The present findings in monkeys suggest that both factors are likely to be true," Nader and colleagues write in a study published online this week in the journal Nature Neuroscience.

Keyword: Drug Abuse; Brain imaging
Link ID: 9126 - Posted: 06.24.2010

Alison Abbott Strokes often change a person's character, depending on where the damage hits. Some may become more impulsive, others depressed. Now researchers have shown that damage to a small but very specific brain area can wipe out an addiction to smoking. Antoine Bechera, of the University of Iowa in Iowa City, has identified 14 patients who all stopped smoking immediately after having a stroke that damaged their insular cortex. This seems to be not because they were concerned about their health, but because they had lost all interest in cigarettes, he told the Federation of Neuroscience Societies in Vienna this week. "One or two had even forgotten that they used to smoke," says Bechera. The insular cortex is a relatively primitive part of the brain whose functions include providing an emotional context for experiences, such as drug taking, along with some higher-level, decision-making functions involved, for example, in forming memories. The seemingly huge impact of switching off this area could have implications for addiction research in general, according to Bechera. Throwing off an addiction for good is tough because cues in the environment — a whiff of tobacco smoke, or the room where you used to shoot up — automatically invokes the emotion associated with the last fix. ©2006 Nature Publishing Group

Keyword: Drug Abuse; Stroke
Link ID: 9125 - Posted: 06.24.2010

By reshaping the cornea, Lasik surgery can correct the eye's ability to focus light onto the cornea.

Keyword: Vision
Link ID: 9124 - Posted: 07.11.2006

By ERIC NAGOURNEY Many people think they don’t get enough sleep. It may be even worse than they realize. Researchers who asked people to wear sleep-measuring devices found that the period of sleep was much shorter than the study subjects believed. The report appears in the July 1 issue of The American Journal of Epidemiology. The researchers, led by Diane Lauderdale of the University of Chicago, found that the people studied had spent an average of seven and a half hours in bed, but just over six hours asleep. They also found significant differences in sleep patterns between men and women and whites and blacks, and among different income groups. The findings suggest that people get less sleep than earlier studies have shown. It also raises questions about the reliability of sleep estimates that people provide to researchers. The 669 volunteers were asked to keep a diary of their sleep over three days, and were given motion-detecting devices worn on the wrist that helped the researchers determine how much they actually slept. The study took into account the normal movements that occur during sleep, Dr. Lauderdale said. Copyright 2006 The New York Times Company

Keyword: Sleep
Link ID: 9123 - Posted: 06.24.2010

A drug that harnesses the power of deadly sea snail venom has been launched in Britain. Prialt is a strong painkiller designed for patients suffering from chronic pain who cannot tolerate treatments like morphine. It is based on a toxin produced by a species of snail from the Philippines. The snail uses venom to paralyze passing fish, but scientists found chemicals in the poison could also block pain signals in the human brain. Conus magus, or the magician's cone snail, is one of about 500 species of cone snail. It hunts by harpooning its prey and injecting it with venom before swallowing now-immobile fish whole. About 25 years ago, scientists at the University of Utah, in the US, managed to isolate a molecule from the venom that also had painkilling properties in humans. The molecule works by preventing nerve cells from sending pain signals to the brain. Now researchers have created a synthetic version of the compound with similar pain-killing effects, and it forms the basis of this new drug, Prialt. Prialt is injected directly into the fluid surrounding the spinal cord through a small pump worn by the patient. (C)BBC

Keyword: Pain & Touch
Link ID: 9122 - Posted: 07.11.2006

By Sandra G. Boodman A major long-term study of girls diagnosed with attention-deficit hyperactivity disorder (ADHD) in elementary school has found they are at greater risk for substance abuse, emotional problems and academic difficulties in adolescence than their peers who don't have the common neurobehavioral condition. The results, experts say, should help dispel the myth that the disorder, which affects an estimated 4.4 million American children, poses less of a risk to girls than to boys, on whom most research has focused. The federally funded study by researchers at the University of California, Berkeley, involves more than 200 girls who have been followed since 1997, when they were 6 to 12. The broadly focused study is designed to measure the ways ADHD, a disorder characterized by pervasive inattention and impulsivity, affects peer relationships, impairs school performance and is linked to substance abuse and psychological problems. "Can you believe it's 2006" and the first long-term prospective study of girls with ADHD is just being published, asked psychologist William Pelham, an ADHD expert at the State University of New York at Buffalo. Girls, Pelham said, have been under-diagnosed and overlooked in large part because their behavior tends to be less disruptive -- although their problems may be just as severe. © 2006 The Washington Post Company

Keyword: ADHD
Link ID: 9121 - Posted: 06.24.2010

Serge Bloch Everybody has limits. I draw the line at women in gorilla suits. I’m not talking about romance. I’m talking about reality as we know it, or think we know it. Except on MTV, the real world has become harder and harder to find. Physics tells us that what we think of as reality is just a particular version of quantum mush or tangled strings cooked up by our limited senses. Cognitive science tells us we’re not even getting the straight dope from our ears and eyes because our brain is concocting a good story from the input. (For the moment let’s not worry about who “we” are. Let’s assume that we know who “we” are.) I can live with that. I imagine the brain as a writer dealing with raw information. You can’t give the reader just the facts, with no transitions or metaphors or narrative structure. So you create a story, or, perhaps, a column. The woman in the gorilla suit is something else again. I’m referring, of course, to the 1999 video known (to those in the know) as the “opaque gorilla video,” which is used in numerous studies of how people fail to see what is right in front of them. It is only 75 seconds long. Copyright 2006 The New York Times Company

Keyword: Attention
Link ID: 9120 - Posted: 06.24.2010

Sleep aids memory. Whether tested in animals or humans, studies have shown that sense memories--such as learning a certain sequence of dance steps--take root more solidly when paired with adequate rest. Now new research shows that so-called declarative memories--such as a sequence of facts--also benefit from slumber, especially when subjects are challenged with subsequent, competing information. Jeffrey Ellenbogen of Harvard Medical School and his colleagues recruited 60 healthy subjects--excluding night owls, the restless and the lethargic--and asked them to memorize 20 pairs of random words, such as blanket and village. The participants were assigned to one of five groups of 12 and had unlimited time to learn the pairings. Two of the groups began learning at 9 A.M and returned for testing at 9 P.M. that evening--with no naps allowed--and two of the groups began learning at 9 P.M. and returned for testing at 9 A.M. the following morning after a night’s sleep. The sleepers barely outperformed their sleepless peers in the first comparison: 94 percent of sleepers accurately recalled the pairings compared to 82 percent of their peers. But when the researchers added a twist--forcing subjects in two of the groups to learn a new set of word pairs 12 minutes prior to testing--the well-rested radically outperformed the sleepy; 76 percent of sleepers accurately recalled the initial pair compared to just 32 percent of their peers who had gone without shut-eye. © 1996-2006 Scientific American, Inc.

Keyword: Sleep; Learning & Memory
Link ID: 9119 - Posted: 06.24.2010

By Briahna Gray A mosquito's hum may drive humans crazy, but to other mosquitoes it's love at first buzz. Now, scientists have discovered that the sound frequencies generated by the insects' beating wings help mosquitoes of the opposite sex coordinate a romantic rendezvous. Finding a mate is tough, especially if your vision isn't very good. Male mosquitoes seem to solve the problem by homing in on the approaching buzz of a potential partner. But how do they tell the guys from the girls? And do females play an active role in this auditory courtship given their smaller and less sensitive antennae? Those have been tough questions to answer, says Gabriella Gibson, a behavioral entomologist at the University of Greenwich in Kent, United Kingdom, particularly because recording the sounds of flying insects is a logistical nightmare. Still, Gibson's team decided to give it a try. Using a dab of beeswax, the researchers separately tethered a male and female mosquito to small clamps via a thin metal wire. They then set up a tiny microphone near each insect. When the female was encouraged to fly, a curious symphony ensued. The male let loose with a flurry of rapid wing beats, creating a higher-frequency buzz than that emitted by the female. In response, the female slightly increased her wing beat frequency to try to match the buzz of the male, with the male slowing his hum frequency dramatically to match hers. Within a second, the buzzes of the two insects were in perfect harmony. © 2006 American Association for the Advancement of Science

Keyword: Sexual Behavior; Hearing
Link ID: 9118 - Posted: 06.24.2010

Experience, as the old saying goes, is the best teacher. And experience seems to play an important early role in how infants learn to understand and produce language. Using new technology that measures the magnetic field generated by the activation of neurons in the brain, researchers tracked what appears to be a link between the listening and speaking areas of the brain in newborn, 6-month-old and one-year-old infants, before infants can speak. The study, which appears in this month's issue of the journal NeuroReport, shows that Broca's area, located in the front of the left hemisphere of the brain, is gradually activated during an infant's initial year of life, according to Toshiaki Imada, lead author of the paper and a research professor at the University of Washington's Institute for Brain and Learning Sciences. Broca's area has long been identified as the seat of speech production and, more recently, as that of social cognition and is critical to language and reading, according to Patricia Kuhl, co-author of the study and co-director of the UW's Institute for Brain and Learning Sciences. "Magnetoencephalography is perfectly non-invasive and measures the magnetic field generated by neurons in the brain responding to sensory information that then 'leaks' through the skull," said Imada, one of the world's experts in the uses of magnetoencephalography to study the brain.

Keyword: Language; Development of the Brain
Link ID: 9117 - Posted: 07.11.2006

David Briscoe, Associated Press —The Navy said it will use active sonar during warfare exercises off Hawaii as early as this weekend, after reaching an agreement with environmentalists who claimed the practice poses a threat to whales and other marine life. The settlement, reached Friday, prevents the Navy from using sonar within 25 miles of the newly established Northwestern Hawaiian Islands Marine National Monument. The agreement also imposes a variety of methods to watch for and report the presence of marine mammals. Navy officials have said the value of training to detect stealthy submarines would have been severely diminished without sonar, which bounces sound off objects in the ocean. "We want to ensure that the U.S. Navy and its partner navies get the benefit of this opportunity to train in anti-submarine warfare," said Rear Adm. James Symonds, director of environmental readiness. The Navy hadn't been allowed to activate sonar under a temporary restraining order issued Monday by U.S. District Court Judge Florence-Marie Cooper in Los Angeles. She lifted the order after the settlement was reached between the environmentalists, the Navy and several federal agencies. © 2006 Discovery Communications Inc.

Keyword: Hearing; Animal Communication
Link ID: 9116 - Posted: 06.24.2010

Roxanne Khamsi “Magic” mushrooms really do have a spiritual effect on people, according to the most rigorous look yet at this aspect of the fungus's active ingredient. About one-third of volunteers in the carefully controlled new study had a “complete” mystical experience after taking psilocybin, with half of them describing their encounter as the single most spiritually significant experience in their lifetimes. However, psilocybin use has been associated with side effects such as severe paranoia, nervousness and unwanted flashbacks and so experts warn against experimentation. “Once you’ve started down the path, you might not like where it ends,” comments Herbert Kleber, a psychiatrist at Columbia University in New York, US. “These are powerful agents that are just as likely to do harm as to do good.” Psilocybin is found in mushrooms such as the liberty cap (Psilocybe semilanceata and about 186 other species. Hippies embraced the compound during the 1960s, after its mind-altering potential was touted by Timothy Leary, then a researcher at Harvard University in Cambridge, Massachusetts. But as its use grew, US lawmakers took action. It is now generally illegal to sell or possess psilocybin drugs in the US. But Roland Griffiths, of Johns Hopkins University School of Medicine in Baltimore, Maryland, US, and his colleagues believe there is a need to revisit the biological effects of psilocybin, which have been virtually ignored by the scientific community for about 40 years. “It so traumatised our society that we’ve demonised this compound,” he says. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 9115 - Posted: 06.24.2010

Helen Phillips A hormone treatment used as a "morning-after" drug to induce abortion could provide a rapid-acting treatment for depression. The drug, called RU486, was one of two new rapid treatment strategies, revealed on Sunday at the Federation of European Neurosciences Society's Annual Forum in Vienna, Austria. Most antidepressants are thought to work by raising levels of the signalling chemical serotonin, which acts in the brain. But these drugs can take several weeks to take effect. The new treatments could be effective within days or even hours. The hormone treatment is based on earlier findings that stress plays a major part in triggering and prolonging depression. Stress hormones appear to damage a part of the brain called the hippocampus. The region is susceptible because it is particularly rich in hormone receptors, allowing it to regulate ongoing hormone release. In experiments on rats, Paul Lucassen from the University of Amsterdam in the Netherlands discovered that stress hormones seemed to be interfering with the birth of new neurons in the region. “The whole turnover of cells is affected,” he reported. © Copyright Reed Business Information Ltd.

Keyword: Depression; Hormones & Behavior
Link ID: 9114 - Posted: 06.24.2010

A blood test to detect the human form of mad cow disease before it causes symptoms is a step closer, say experts. Spanish and US scientists have found a way to detect infection in hamsters before the animal shows signs of illness. More work is needed before a similar test could be used in humans, but the findings offer hope of a screening test for vCJD, Science reports. Currently, it is only possible to confirm vCJD infection after death. A test for vCJD is badly needed, especially now that some cases appear to have been transmitted by blood transfusions, say Dr Paula Saa and colleagues from the University of Texas. In the UK, there have been three reported cases of variant-CJD associated with a blood transfusion to date. The first of these was identified in December 2003. Since then the Department of Health has asked all recipients of blood transfusions not to donate blood as a precautionary measure to protect the blood supply from vCJD. This is because it has not yet been possible to screen donated blood for vCJD, unlike some other infections. The test developed by Dr Saa's team detects prion proteins - the infectious agents that are thought to be responsible for vCJD. Normally, prion concentrations are only high enough to be detectable in the brain and some lymphoid tissue at a time close to they symptomatic stage of the disease. To get round this, the scientists used a technique called protein misfolding cyclic amplification (PCMA) which amplifies the quantity of prion proteins in any sample taken from the body. (C)BBC

Keyword: Prions
Link ID: 9113 - Posted: 07.10.2006

By BENEDICT CAREY WHEN a war crime doesn't look quite like a war crime — when it seems cold and deliberate like a serial murder, rather than an impulsive act of vengeance — it can be especially disturbing, as United States Army officials have learned over the past week. According to federal prosecutors, an Army private and several comrades attacked an Iraqi family last March, raping and killing a young woman after executing her parents and her younger sister in their home. The men disguised themselves for the attack and worked as a team, the prosecutors said. Iraqi leaders are in an uproar, as are American officials in and out of the military. The accused ringleader, Steven D. Green, 21, who was discharged in May, pleaded not guilty after his arrest June 30, and details of the crime were still emerging last week. The Army has said it discharged Mr. Green for a "personality disorder." Which raises a question: How does someone with a personality disorder — a significant, disabling, and dangerous condition — manage the stress of combat? Wouldn't a person with a serious mental problem drop out, or be identified and quickly discharged? Copyright 2006 The New York Times Company

Keyword: Aggression
Link ID: 9112 - Posted: 06.24.2010

At the tender age of 10 days or so young rats first venture outside the nest, leaving the comforting presence of their mother. The world outside is full of perils and promise and the pups must learn the difference. But the presence or absence of their mother may make all the difference in determining which is which, according to new research published online yesterday in Nature Neuroscience. Stephanie Moriceau and Regina Sullivan of the University of Oklahoma tested how baby rats responded to the pairing of an unfamiliar odor--peppermint--and a weak electric shock to their tails. The charge-laced scent attracted the youngest pups without exception while repelling their older siblings of 21 days--the age when rats become fully independent. But young rats between 12 and 15 days old either learned to love the peppermint despite the shock if their mother was present or learned to fear it if she was not. When presented with the odor later in a Y-maze, the mothered pups would invariably move toward it while their motherless counterparts would move away. © 1996-2006 Scientific American, Inc

Keyword: Emotions; Sexual Behavior
Link ID: 9111 - Posted: 06.24.2010

Cuttlefish are wizards of camouflage. Adept at blending in with their surroundings, cuttlefish are known to have a diverse range of body patterns and can switch between them almost instantaneously. New research from MBL Marine Resources scientists, to appear in the May 2006 issue of the journal Vision Research, confirms that while these masters of disguise change their appearance based on visual cues, they do so while being completely colorblind. While previous research has reported cuttlefish colorblindness, MBL Research Associate Lydia Mäthger and her colleagues in Roger Hanlon’s laboratory approached the problem in more depth and with a new behavioral assay. The researchers tested cuttlefish (Sepia officinalis) color perception through observing the animal’s behavioral response to a series of checkerboard patterned substrates of various colors and brightnesses. They found that the animals did not respond to the checkerboard pattern when placed on substrates whose color intensities were matched to the Sepia visual system, suggesting that these checkerboards appeared to their eyes as uniform backgrounds. However, their results showed that cuttlefish were able to detect contrast differences of at least 15%, which Mäthger and her colleagues suspect might be a critical factor in uncovering what determines camouflage patterning in cuttlefish. © 2005 by The Marine Biological LaboratoryTM

Keyword: Vision
Link ID: 9110 - Posted: 06.24.2010

By Jason Stahl 1 Chronic snoring can be treated by uvulopalatopharyngoplasty, a surgical procedure that tightens the tissues of the soft palate and throat. Possible side effects include changes in voice frequency. 2 Another option involves injecting the palate with a chemical to harden the soft tissue. This is called a snoroplasty, derived from the Greek word plastos, meaning molded, and somewhat lamely from the English word snore, meaning snore. 3 Baaaa'd idea: A 2002 study by Oxford University researchers concluded, brilliantly, that the traditional practice of counting sheep is an ineffective cure for insomnia. The mental activity is so boring that other problems and concerns inevitably surface. 4 Mattresses have an average life span of 8 to 10 years. They grow some nasty stuff in that time; one study links mattress bacteria to sudden infant death syndrome. 5 An adult bedbug can survive up to one year without feeding. 6 In 2004 Americans filled more than 35 million prescriptions for sleeping pills.The number of adults aged 20 to 44 taking pills to help them fall asleep has doubled in the last four years. © 2005 Discover Media LLC.

Keyword: Sleep
Link ID: 9109 - Posted: 06.24.2010

Blood levels of two proteins important in Alzheimer's disease may predict pending dementia, say scientists. High levels of one amyloid protein and low levels of another were linked with a more than 10-fold increased dementia risk among the 1,756 people studied. The Dutch researchers from the Erasmus Medical Centre say more work is now needed to see whether the markers could be used as a dementia blood test. Diagnosing dementia is often difficult, particularly in the early stages. There is no simple test to make a diagnosis of dementia, and it can only be confirmed with certainty by examining someone's brain in a post mortem. In Alzheimer's disease, plaques comprised of amyloid can be seen in the brain. Past research has also shown that people with mutations that cause early-onset Alzheimer's disease can have high blood concentrations of amyloid proteins. Dr Monique Breteler and her team set out to investigate whether increased blood concentrations of amyloid proteins might be associated with the development of dementia. They followed 1,756 people known to be at risk for dementia. Over the eight years, 392 of the people developed dementia. Increasing blood concentrations of one type of amyloid protein, Aß1-40, was associated with an increased risk of dementia, particularly when the concentration of another amyloid protein, Aß1-42, was low in the blood. (C)BBC

Keyword: Alzheimers
Link ID: 9108 - Posted: 07.08.2006

Even when they really want to quit, the craving can suck smokers into lighting up again. But University of Minnesota addiction researcher Kola Okuyemi wants to know why it seems to affect some ethnic groups more than others. "African Americans, in general, even though they smoke fewer cigarettes per day compared to Caucasians, they have a harder time quitting smoking," he says. Smoking cessation research targeted at the African American community is critical, because smoking affects a disproportional amount of African Americans. According to the American Lung Association, "African Americans have lower overall exposure to tobacco smoke, but are more susceptible to developing smoking-related illnesses. African American men are 50 percent more likely than white men to develop lung cancer." "And in order for us to be able to reduce the disparities," Okuyemi says, "the disparities that we see in the success with which people quit smoking, we need a better understanding on why it is that African Americans have a harder time quitting smoking." So to investigate, Okuyemi and his team put 34 volunteers into an MRI brain scanning machine and showed them equal amounts of photos of African Americans and Caucasians smoking. These photos, called "smoking cues," are meant to provoke a response in certain parts of the brain. © ScienCentral, 2000-2006.

Keyword: Drug Abuse
Link ID: 9107 - Posted: 06.24.2010