Implications range from economic theory to addiction research You walk into a room and spy a plate of doughnuts dripping with chocolate frosting. But wait: You were saving your sweets allotment for a party later today. If it feels like one part of your brain is battling another, it probably is, according to a newly published study. Researchers at four universities found two areas of the brain that appear to compete for control over behavior when a person attempts to balance near-term rewards with long-term goals. The research involved imaging people's brains as they made choices between small but immediate rewards or larger awards that they would receive later. The study grew out of the emerging discipline of neuroeconomics, which investigates the mental and neural processes that drive economic decision-making. The study was a collaboration between Jonathan Cohen and Samuel McClure at Princeton's Center for the Study of Brain Mind and Behavior; David Laibson, professor of economics at Harvard University; and George Loewenstein, professor of economics and psychology at Carnegie Mellon University. Their study appears in the Oct. 15 issue of Science. "This is part of a series of studies we've done that illustrate that we are rarely of one mind," said Cohen, also a faculty member at the University of Pittsburgh. "We have different neural systems that evolved to solve different types of problems, and our behavior is dictated by the competition or cooperation between them."

Keyword: Drug Abuse; Brain imaging
Link ID: 6249 - Posted: 10.15.2004

By SCOTT SHANE WASHINGTON, - A federal panel of medical experts studying illnesses among veterans of the 1991 war in the Persian Gulf has broken with several earlier studies and concluded that many suffer from neurological damage caused by exposure to toxic chemicals, rejecting past findings that the ailments resulted mostly from wartime stress. Citing new scientific research on the effects of exposure to low levels of neurotoxins, the Research Advisory Committee on Gulf War Veterans' Illnesses concludes in its draft report that "a substantial proportion of Gulf War veterans are ill with multisymptom conditions not explained by wartime stress or psychiatric illness." It says a growing body of research suggests that many veterans' symptoms have a neurological cause and that there is a "probable link" to exposure to neurotoxins. The report says possible sources include sarin, a nerve gas, from an Iraqi weapons depot blown up by American forces in 1991; a drug, pyridostigmine bromide, given to troops to protect against nerve gas; and pesticides used to protect soldiers in the region. Copyright 2004 The New York Times Company

Keyword: Neurotoxins
Link ID: 6248 - Posted: 10.15.2004

From language to literature, from music to mathematics, a single protein appears central to the formation of the long-term memories needed to learn these and all other disciplines, according to a team of researchers led by scientists at the National Institute of Child Health and Human Development of the National Institutes of Health. Their findings appear in the October 15 issue of Science. The protein is known as mBDNF, which stands for mature brain-derived neurotrophic factor. It appears to chemically alter neurons, boosting their ability to communicate with one another. "Most of what we accomplish as human beings depends on what we learn," said Duane Alexander, M.D., Director of the National Institute of Child Health and Human Development. "This discovery brings the possibility of studying this protein system in people with disorders of learning and memory and perhaps designing new medications that might help to compensate for these problems." Researchers recognize two broad categories of memory--short term memory, and long term memory. Short term memory refers to the transient memories that last from minutes to hours. Long term memory refers to the ability to remember things for more than a day--sometimes for many years.

Keyword: Learning & Memory; Trophic Factors
Link ID: 6247 - Posted: 10.15.2004

EVANSTON, Ill. --- False memories are the controversial subject of hotly contested arguments about the validity of repressed memories that can surface years after a traumatic event and about the credibility of eyewitness accounts in criminal trials. Because memories are imperfect under ordinary circumstances -- forming, storing and retrieving them, with great variations in factors influencing those processes -- it is unlikely that a one-answer-fits-all will settle those controversies soon. But a group of researchers from various disciplines at Northwestern University literally have peered into the brain to offer new evidence on the existence of false memories and how they are formed. Published in the journal Psychological Science, the new study used MRI technology to pinpoint how people form a memory for something that didn't actually happen. "Our challenge was to bring people into the laboratory and set up a circumstance in which they would remember something that did not happen," said Kenneth A. Paller, professor of psychology and co-investigator of the study. (Brian Gonsalves, who was a doctoral student of Paller's and who now is a post-doctoral fellow at Stanford University, is the first author of the paper.)

Keyword: Learning & Memory
Link ID: 6246 - Posted: 10.15.2004

An anti-epilepsy drug first licensed in the UK in 1975 may cause long-term developmental problems in children born to pregnant women using it, suggest the results of a new study. Epilepsy experts already believe there is a strong link between using drugs containing sodium valproate during pregnancy and dysmorphic features - such as eyes set wider apart and a thinned upper lip - in children born subsequently. They have suspected that valproate use in pregnant mothers may also lead to longer term developmental problems in their children - but until now the evidence for this has been anecdotal. “The new research is saying something we’ve guessed for a long time,” says Tim Betts, a neuropsychiatrist at the University of Birmingham, UK. “Now they’ve measured it for the first time. It’s very important work.” The study, led by Naghme Adab from the Walton Centre for Neurology and Neurosurgery, Liverpool, UK, shows that children born to mothers who were on valproate when pregnant were eleven times more likely to have a verbal IQ score of 69 or below, compared with children born in the general population. © Copyright Reed Business Information Ltd.

Keyword: Epilepsy; Development of the Brain
Link ID: 6245 - Posted: 06.24.2010

Certain genes are expressed differently in people with depression (SACRAMENTO, Calif.) -- Researchers have found altered gene activity in people who suffer from major depression, a discovery that may one day help doctors better diagnose and treat the condition. The research, conducted by a consortium of four universities, appears this week in the online edition of the Proceedings of the National Academy of Sciences USA (PNAS). Scientists found that the fibroblast growth factor system, which is a family of proteins involved in the growth, development and maintenance of nerve cells, had an overall decrease in levels in patients who had major depressive disorder. Proteins are the products of gene expression. "This study is the first to implicate this particular family of gene products in major depression," said Edward G. Jones, professor of psychiatry and director of the Center for Neuroscience at UC Davis and a principal investigator of the study. "The fibroblast growth factor system is now important to consider when looking for causes of mood disorders." Growth factors bind to receptors on the surface of cells, setting in motion a variety of biological activities. The fibroblast growth factors are critical during brain development and also help maintain the central nervous system in adulthood.

Keyword: Depression; Genes & Behavior
Link ID: 6244 - Posted: 10.15.2004

By MARTICA HEANER When his clock-radio goes off at 7 a.m., David Epstein's latest wake-up strategy roars into high gear: he stumbles out of bed, walks across the room and pushes the snooze button. Then he climbs between the sheets. A few minutes later, his travel clock rings. He presses snooze and rolls over for more sleep - until the alarm on his BlackBerry goes off. Sitting up, he punches keys to reset it for 10 more minutes, then it's back to the pillow. The pattern repeats amid a cacophony of assorted rings until his real wake-up time, 8 a.m. In a nation that clocks around six to seven hours of sleep a night when an average of eight hours is recommended, it is a rare person who wakes up without an alarm. And because it is usually a struggle, pushing snooze to delay the day has become as much a part of the wake-up ritual as a cup of coffee. But is a bumpy arousal for 30, 60 or even 90 minutes a way to recoup much-needed sleep? Or is it a recipe for exhaustion? Copyright 2004 The New York Times Company

Keyword: Sleep
Link ID: 6243 - Posted: 10.14.2004

By Jennifer KahnPage I am not cool. For starters, I don't listen to music. It disrupts my concentration and makes me cranky. I'm anxious at parties, always hoping that someone will turn down the stereo so that we can all break off into small groups and talk, preferably about science or books. My ideal evening ends early, around 10, freeing me to go home and read. At the party, everyone would wear something comfortable, possibly flannel. If coolness is formed early on - as it often seems to be - I never stood a chance. In eighth grade, when most of my classmates spent lunch clustered in small, gossipy cliques, I distinguished myself by cantering around the school grounds like a horse, neighing and occasionally leaping over a bench. Although I dressed carefully, I could never pull off the stylish look of my peers. In fifth grade, I struggled to roll my jeans so that they hung slightly flooded, as was the fashion. I never quite succeeded, and it didn't help that the rest of my wardrobe reflected an unusual taste for velour (I had three favorite, otherwise identical, velour sweaters in yellowish dun, turquoise, and red), as well as a lingering love of appliquéd unicorns. Fifth grade was also the year that I discovered, to my shame, that the seventh grader I had privately idolized was actually the class dork, a turtleneck-and-glasses-wearing nerd incarnate. © Copyright© 1993-2004 The Condé Nast Publications Inc.

Keyword: Brain imaging
Link ID: 6242 - Posted: 06.24.2010

While neurobiologists have long suspected that certain regions of the brain are specifically involved in making decisions, the challenge has been to develop rigorous laboratory behavioral experiments that could pinpoint those areas. Now, Paul Glimcher and colleague Michael Dorris have used a game-playing approach to demonstrate that a region of the cortex called the lateral intraparietal (LIP) area is active when monkeys are making subjective internal decisions about the desirability of an action--in this case, moving their eyes to a target. According to the researchers, their findings represents a step toward understanding the machinery by which the brain processes decisions. In their studies, the researchers first tested the behavior of humans competing in a game in which a player was asked to click on a computer mouse to choose one of two buttons to receive either a certain monetary reward or a risky choice that could yield a larger reward. An opponent, meanwhile, was asked to select an option that would prevent the reward, and the researchers could vary the cost to the opponent of making that selection. The basic aim of the researchers was to create a situation in which there was no single correct choice, so that subjects adopted a mixed strategy, reflecting that the subjective desirability of the choices was equal.

Keyword: Vision
Link ID: 6241 - Posted: 10.14.2004

The preference for Coke versus Pepsi is not only a matter for the tongue to decide, Samuel McClure and his colleagues have found. Brain scans of people tasting the soft drinks reveal that knowing which drink they're tasting affects their preference and activates memory-related brain regions that recall cultural influences. Thus, say the researchers, they have shown neurologically how a culturally based brand image influences a behavioral choice. These choices are affected by perception, wrote the researchers, because "there are visual images and marketing messages that have insinuated themselves into the nervous systems of humans that consume the drinks." Even though scientists have long believed that such cultural messages affect taste perception, there had been no direct neural probes to test the effect, wrote the researchers. Findings about the effects of such cultural information on the brain have important medical implications, they wrote. "There is literally a growing crisis in obesity, type II diabetes, and all their sequelae that result directly from or are exacerbated by overconsumption of calories. It is now strongly suspected that one major culprit is sugared colas," they wrote. Besides the health implications of studying soft drink preference, the researchers decided to use Coke and Pepsi because-- even though the two drinks are nearly identical chemically and physically--people routinely strongly favor one over the other. Thus, the two soft drinks made excellent subjects for rigorous experimental studies.

Keyword: Obesity; Brain imaging
Link ID: 6240 - Posted: 10.14.2004

— Fossil hunters in China have found the remains of a new species of dinosaur caught in bird-like mid-slumber, curled up with its head tucked under a forelimb. In the study, published Thursday in the journal Nature, Xing Xu of the Chinese Academy of Sciences in Beijing and Mark Norell of the American Museum of Natural History described the animal, dubbed Mei long, or "soundly sleeping dragon." The creature, just 53 centimeters (21 inches) long, lived between 128-139 million years ago. The earliest known example of a dinosaur found in a bird-like position, Mei long demonstrates that the classic bird-like sleeping posture probably first appeared in the dinosaur ancestors of modern birds. The researchers said it lends further support to the theory that birds emerged from dinosaur species which, under evolutionary pressure, became smaller, grew feathers and developed claws adapted to climbing and living in trees. Also, the animal's size adds to the theory that the smallness of birds' dinosaur ancestors was critical to their ultimately being able to fly. Copyright © 2004 Discovery Communications Inc.

Keyword: Sleep; Evolution
Link ID: 6239 - Posted: 06.24.2010

Clumps of defective proteins, long implicated in killing off part of the brain in Huntington's disease, may actually be helping these neurons to survive. The discovery could redirect efforts to develop treatments for Huntington's disease (HD) - a disorder that slowly kills brain cells involved in movement and higher cognitive function. HD is triggered by mutations in a protein called huntingtin which cause the protein to aggregate and ultimately form large cellular blobs known as inclusion bodies. These insoluble blobs are visible under a microscope and may contain thousands of mutant proteins. Scientists had believed that inclusion bodies help destroy neurons, since animals sick with HD have these blobs in their brain cells while healthy animals do not. And, in general, the sicker animals become with the disease, the more inclusion bodies are found in the neurons of damaged brain areas. © Copyright Reed Business Information Ltd.

Keyword: Huntingtons
Link ID: 6238 - Posted: 06.24.2010

Roxanne Khamsi An pill-sized brain chip has allowed a quadriplegic man to check e-mail and play computer games using his thoughts. The device can tap into a hundred neurons at a time, and is the most sophisticated such implant tested in humans so far. Many paralysed people control computers with their eyes or tongue. But muscle function limits these techniques, and they require a lot of training. For over a decade researchers have been trying to find a way to tap directly into thoughts. In June 2004, surgeons implanted a device containing 100 electrodes into the motor cortex of a 24-year-old quadriplegic. The device, called the BrainGate, was developed by the company Cyberkinetics, based in Foxborough, Massachusetts. Each electrode taps into a neuron in the patient's brain. The BrainGate allowed the patient to control a computer or television using his mind, even when doing other things at the same time. Researchers report for example that he could control his television while talking and moving his head. The team now plans to implant devices into four more patients. ©2004 Nature Publishing Group

Keyword: Robotics
Link ID: 6237 - Posted: 06.24.2010

(Akron, Ohio) – The journal, Obesity Research, today published an article on the results of a 24-month federally funded obesity study led by Summa Health System researchers in Akron, Ohio. The study is the first to document that patients who spend a longer time in the action and maintenance stages for portion control or planned exercise were more likely to lose weight. The reverse was also true. Patients who spend less time in the action and maintenance stages for portion control or planned exercise were more likely to gain weight. According to lead Summa researcher Everett E. Logue, Ph.D., the greatest weight loss in the study was related to portion control. "Although we saw similar patterns of weight loss related to reduced dietary fat consumption, increased fruit and vegetable consumption, increased physical activity and increased planned exercise, the target behavior that induced the greatest weight loss was portion control." While Logue points out portion control showed the greatest weight loss, the study also suggests planned exercise induced the least. This however, does not surprise Logue. "Portion control may be behaviorally easier to change than increasing planned exercise for many obese individuals," Logue said. "However, other research suggests that planned exercise is an important component of long-term weight management."

Keyword: Obesity
Link ID: 6236 - Posted: 06.24.2010

Using a specially designed robotic microscope to study cultured cells, researchers have found evidence that abnormal protein clumps called inclusion bodies in neurons from people with Huntington's disease (HD) prevent cell death. The finding helps to resolve a longstanding debate about the role of these inclusion bodies in HD and other disorders and may help investigators find effective treatments for these diseases. The study was funded primarily by the NIH's National Institute of Neurological Disorders and Stroke (NINDS) and appears in the October 14, 2004, issue of Nature.1 Inclusion bodies are common to many neurodegenerative disorders, including HD, Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS). The role of inclusion bodies in these diseases has long been controversial. Some studies suggest that they may be a critical part of the disease process, while others indicate that they may help protect the cells from toxic proteins or that they are merely bystanders in the disease process. One problem in identifying how inclusion bodies influence disease is that researchers have been unable to track changes in individual neurons over time. "It was like viewing pictures of a football game and trying to imagine the score," says Steven Finkbeiner, M.D., Ph.D., of the Gladstone Institute of Neurological Disease and the University of California, San Francisco. "Much was happening that we couldn't see."

Keyword: Huntingtons; ALS-Lou Gehrig's Disease
Link ID: 6235 - Posted: 10.14.2004

Two groups of researchers have independently discovered the long sought dual body clocks in the brain of fruit flies that separately govern bursts of morning and evening activity. Both research groups published their findings in the October 14, 2004, issue of the journal Nature. Howard Hughes Medical Institute researcher Michael Rosbash at Brandeis University led one group; François Rouyer at the Centre National de la Recherche Scientifique in France led the second group. Graduate students Dan Stoleru and Ying Peng of Brandeis were co-lead authors of the Rosbash group's article. In an accompanying News & Views article in the journal Nature, neurobiologist William J. Schwartz of the University of Massachusetts Medical School, writes, “A truly integrative circadian biology is close at hand, as researchers learn about an adaptable, layered system that has emergent properties at many levels of organization. Drosophila workers, who have been so effective at taking the clock apart, are now succeeding in putting it back together.” © 2004 Howard Hughes Medical Institute.

Keyword: Biological Rhythms
Link ID: 6234 - Posted: 06.24.2010

Researchers have identified a molecule that can transform the mechanical stimulus of a sound wave into an electrical signal recognizable by the brain. The protein forms an ion channel that opens in response to sound, causing electrical impulses that communicate the pitch, volume, and duration of a sound to the brain. Scientists have long suspected that such a molecule must exist in the tiny cilia extending from receptor cells in the inner ear. Now, researchers led by Howard Hughes Medical Institute investigator David P. Corey, who is at Harvard Medical School, have several lines of evidence that, in vertebrates, this mechanosensitive channel is formed by a protein known as TRPA1. Certain features of the protein suggest that it may serve double, or even triple, duty in the inner ear, not only acting as an ion channel, but also forming a spring that allows the transduction machinery to stretch, and even amplifying incoming auditory signals. The work is published October 13, 2004, in an advance online publication of the journal Nature. The cells that line the inner ear and convert mechanical sound vibrations into electrical impulses are known as hair cells - named for the tuft of 30-300 cilia, or microscopic hairs, on each cell's surface. Thin filaments called tip links connect the channels in adjacent hairs, so that when a vibration stirs the bundle of cilia, the tip links are tightened and pull on the channels. Within 5 to 10 microseconds of this motion, channels in the hair cell open and allow ions to enter - the first step in sending a sound signal to the brain. © 2004 Howard Hughes Medical Institute.

Keyword: Hearing
Link ID: 6233 - Posted: 06.24.2010

St. Paul, Minn. – Certain blood pressure drugs may slow the deterioration of Alzheimer’s disease, according to a study published in the October 12 issue of Neurology, the scientific journal of the American Academy of Neurology. Called angiotensin-converting enzyme inhibitors, or ACE inhibitors, the drugs are used to treat high blood pressure. Only ACE inhibitors that can penetrate the blood-brain barrier were shown to have the effect on Alzheimer’s. The blood-brain barrier is a natural protective mechanism that shields the brain from foreign substances. The study involved 162 people in Japan living in long-term care facilities with mild to moderate Alzheimer’s disease and high blood pressure. The participants were divided into three groups. For one year, each group received either a brain-penetrating ACE inhibitor, a non-brain-penetrating ACE inhibitor, or another type of blood pressure drug, called a calcium channel blocker. Those in the brain-penetrating ACE inhibitor groups received one of two drugs – perindopril or captopril.

Keyword: Alzheimers
Link ID: 6232 - Posted: 06.24.2010

St. Paul, Minn. – A recent analysis of tamoxifen studies completed since 1980 revealed an increased risk of stroke in women who were randomized to tamoxifen versus placebo or other therapies. Details of the analysis and the researchers’ conclusions are reported in the October 12 issue of Neurology, the scientific journal of the American Academy of Neurology. More than 250,000 U.S. women are diagnosed with breast cancer each year. Breast cancer accounts for nearly one in three cancers diagnosed in the U.S. and is the second leading cause of death for women. Fortunately, 90 percent of breast cancers are now diagnosed at localized and regional stages, for which five-year survival rates are 97 percent and 79 percent, respectively. Tamoxifen, a medication in pill form that interferes with the activity of estrogen, has been used for more than 20 years to treat patients with advanced breast cancer. It is used as adjuvant, or additional, therapy following primary treatment for early stage breast cancer. In women at high risk of developing breast cancer, tamoxifen reduces the chance of developing the disease. In addition to its effects on breast cancer, the benefits of tamoxifen include increased bone mineral density, reduced risk of hip fractures, and lower levels of cholesterol. While tamoxifen is known to increase the risk of blood clotting in women with cancer, its relationship to stroke risk has been unclear.

Keyword: Stroke; Hormones & Behavior
Link ID: 6231 - Posted: 06.24.2010

Children born prematurely have smaller brains on average than full-term kids and preterm boys are most affected. This ScienCentral News video reports on the latest results from the oldest and largest study of preterm kids. Every day, 1,300 babies are born prematurely in the U.S. Although the survival rate is much better than it used to be thanks to medical advances, there are still problems with preterm babies—including the fact that while many preemies catch up to their peers in development, they have a higher rate of learning problems when they get to grade school. "Now in the U.S. children who weigh less than three pounds represent over two percent of all live births every year," says Laura Ment, pediatrics and neurology professor at Yale University School of Medicine. "The survival rate for this group of children is anywhere from 85 to 90 percent. So there are more preemies and there's more of them surviving, but if you consider the fact that half of them are in special education at age eight, in second or third grade, and one fifth of them have already repeated a grade in school, then preterm birth is really what we would consider a major pediatric public health problem." © ScienCentral, 2000- 2004.

Keyword: Development of the Brain
Link ID: 6230 - Posted: 06.24.2010