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

TALLAHASSEE, Fla. You might want to toss those iron-fortified vitamins, because absent a diagnosed deficiency too much of a good thing can be bad. Dietary iron imbalances either way spell trouble for healthy cells, triggering a chain of cellular events in the brain that increases the odds of developing Parkinson's disease, a degenerative condition affecting movement and balance in more than 1 million Americans each year. But excessive iron levels are worse -- much worse. The findings from a study by Florida State University scientist Cathy Levenson are described in "The Role of Dietary Iron Restrictions in a Mouse Model of Parkinson's Disease" and will appear in an upcoming edition of Experimental Neurology. Levenson is an associate professor of nutrition, food and exercise sciences in FSU's College of Human Sciences and a faculty member in both the Program in Neuroscience and graduate program in molecular biophysics. "We define our work here at the cellular level," said Levenson from her laboratory at FSU's Biomedical Research Facility. "Our primary research objective is to better understand how trace metal imbalances, which are associated with neuropsychiatric and neurodegenerative diseases, affect the molecular mechanisms that regulate gene expression."

Keyword: Parkinsons
Link ID: 6229 - Posted: 10.13.2004

Michael Hopkin A survey of Italian men has provided evidence that homosexuality may be partly influenced by genetics. The same genes that are proposed to predispose to homosexuality may also boost reproduction in women, solving the apparent paradox of why these genes have not been removed by natural selection. By quizzing around 200 men of different sexual orientations, researchers at the University of Padua have discovered that maternal relatives of homosexual men tend to produce more offspring than those of heterosexuals. This suggests that the mothers and maternal aunts of homosexuals have a genetic advantage - but one that reduces reproduction when passed to male offspring. "For a long time it has been a paradox," says Andrea Camperio-Ciani, who led the study. "But we have found that there might be a set of genes that, in males, influences homosexuality but in females increases fecundity." ©2004 Nature Publishing Group

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 6228 - Posted: 06.24.2010

A recent study published in Epilepsia, the official journal of the International League Against Epilepsy (ILAE), indicates that people who have uncontrolled seizures on the left side of their brains are more likely to have learning disabilities, in comparison to people who have seizures on the right side of their brains. Epilepsy, a neurological disorder associated with recurrent seizures, affects 0.5% to 1% of the population. In theU.S., about 2.5 million people have this disorder and about 9% of Americans will have at least one seizure during their lives. In the study conducted at the LSU Epilepsy Center of Excellence, adult patients of normal intelligence with either left temporal lobe epilepsy (TLE) or right TLE were evaluated with reading comprehension, written language, and calculation tests. The Center researchers found that 75% of patients with left TLE had one or more learning disabilities. This was found in only 10% of those with right TLE. Additionally, those with left TLE reported higher rates of literacy and/or career development problems, such as a history of special education, repeating grades, or disrupted educational progress.

Keyword: Epilepsy; Learning & Memory
Link ID: 6227 - Posted: 10.13.2004

Flight simulators used to train pilots and astronauts can provide relief from chronic dizziness, a study shows. Researchers from Hammersmith Hospitals NHS Trust and Imperial College London treated 40 patients with a history of balance problems. They found twice weekly visual stimulation sessions for two months helped reduce the frequency and intensity of dizziness by up to a half. A third of people experience dizziness or vertigo at some during their lives. For many it clears up quickly but some can experience episodes of dizziness for years. Vertigo, dizziness and feelings of nausea are related to the inner ear, known as the vestibular system. The inner ear is a complex arrangement of fluid-filled chambers that acts like a mercury tilt-switch, relaying information about balance to the brain. When disrupted by a disease such as flu or a head injury the signals become confused. The team put all the patients through a the standard treatment of physiotherapy with half also completing the stimulator therapy sessions. The sessions involved using a rotating disk, spinning chair and video-based exercises, all of which are used to train pilots and astronauts. The treatment is known to strengthen the visual input to the brain, improving balance and reducing dizziness - essential to reduce motion sickness for people who fly. (C)BBC

Keyword: Miscellaneous
Link ID: 6226 - Posted: 10.12.2004

By JOHN SCHWARTZ The death of Christopher Reeve illustrated something that those who live with paralysis know all too well: the challenges go far beyond the inability to walk. "Walking is the least of it," said Donna Messinger, who is 43 and has been paralyzed since an automobile accident in her senior year of college. Mr. Reeve died of cardiac arrest on Sunday. He had previously been treated for a severe systemic infection that was, in turn, caused by a pressure wound, the medical term for a bedsore, a common complication for people who are paralyzed. Mr. Reeve was, in fact, one of the lucky ones. Though his injuries were among the most severe possible, he also had the resources to get the best treatment. "He had extraordinarily good state-of-the-art care, which is not necessarily something available to everyone who suffers a spinal cord injury," said Susan Howley, the executive vice president and director for research the Christopher Reeve Paralysis Foundation in Springfield, N.J. Infection is perhaps the biggest enemy for people with such injuries. According to the Infectious Diseases Society of America, some form of infection is the No. 1 cause of death among patients who are paralyzed from the waist down. Mr. Reeve's own problems with pressure sores show how difficult they can be. Patients who cannot move for themselves must be shifted and turned regularly during the day and often must have 24-hour nursing care. Copyright 2004 The New York Times Company

Keyword: Pain & Touch
Link ID: 6225 - Posted: 10.12.2004

By MICHAEL ERARD Not by the hair of my chinny chin chin," the three little pigs taunted the big bad wolf. When Anna Van Valin was 4 years old, she pronounced the phrase "not by the chair of my hinny hin hin" and unwittingly advanced the study of children's language when she did. Anna's talk was often observed. Her mother, Dr. Jeri Jaeger, is a linguist at the State University of New York at Buffalo who collects the speech slips that children make in order to understand how they learn language. For two decades Dr. Jaeger has collected data wherever she found available children (and willing parents): preschools, the supermarket checkout line and at home from her three children, Anna, Alice and Bobby (now 22, 20 and 18). A photo of Anna as a 6-year-old appears on the cover of Dr. Jaeger's new book, "Kids' Slips," to be published this month.. Anna's first error occurred when she was 16 months old. She rattled out the phrase, "one, two, three," but accidentally pushed "two" and "three" together, which came out something like "twee." In such an instance, Dr. Jaeger said: "Many parents get freaked out and think their child is making mistakes. But these slips of the tongue are entirely normal. In fact, they show that a child is acquiring language as they should be." Copyright 2004 The New York Times Company

Keyword: Language; Development of the Brain
Link ID: 6224 - Posted: 10.12.2004

EVANSTON, Ill. --- Soap bubbles delight children and the young at heart, but they also have been objects of scientific study for centuries. Operating under the laws of physics, bubbles always try to minimize their surface area, even when many bubbles are aggregated together. Now two Northwestern University scientists have demonstrated that the tendency to minimize surface area is not limited to soap bubbles but extends to living things as well. In a paper published Oct. 7 in the journal Nature, they show that cells within the retina take on shapes and pack together like soap bubbles, ultimately forming a pattern that is repeated again and again across the eye. Gaining insight into these patterns can help researchers understand the interplay between genetics and physics in cell formation. "The cells we studied, those found in the retina of the fruit fly, adopt mathematically predictable shapes and configurations," said Richard W. Carthew, professor of biochemistry, molecular biology and cell biology and a co-author on the paper. "Like bubbles, life has co-opted a physical tendency for surfaces to be minimized and has harnessed it to design intricate cellular patterns within complex structures such as the eye." Similar to the colored dots in a Georges Seurat painting, though on a three-dimensional scale, the cell is the indivisible unit that gives shape to something larger and recognizable -- a butterfly, a maple tree, a human being. How is this amazing diversity of species created?

Keyword: Vision; Development of the Brain
Link ID: 6223 - Posted: 10.12.2004

By Larry O'Hanlon, Discovery News — British researchers have created an electronic tongue that could someday help keep people safe from spoiled or contaminated food, water and drugs. Designed at the University of Warwick, England, the high-tech taster is capable of detecting the four basic tastes: sour, sweet, salt and bitter. The new tongue is reported in the Sept. 29 issue of the journal Sensors and Actuators B: Chemical. "Electronic tongues are likely to find use in food and clinical labs especially for testing of bitter or obnoxious substances such as urine," said electric sensor researcher Anil Deisingh of the University of the West Indies in Trinidad & Tobago. So far, however, they are being tested on slightly less repulsive substances. "We have used it to test freshness of milk," said Marina Cole, one of the electric tongue's developers. Unlike other electronic tongues being developed, the new tongue has no taste buds. Instead of having chemical membranes to detect sweet, sour, salty or bitter chemicals, like human tastebuds, the new tongue doesn't taste at all — it hollers and listens. Copyright © 2004 Discovery Communications Inc.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6222 - Posted: 06.24.2010