Brain & Behavior

Hitchhiking rocks provide details of glacial melting in West Antarctic

Rocks deposited by glaciers on mountain ranges in West Antarctica have given scientists the most direct evidence yet that parts of the ice sheet are on a long-term, natural trajectory of melting. The West Antarctic Ice Sheet has been melting and contributing water continuously to the ocean for the last 10,000 years and is likely to keep doing so, says John Stone, University of Washington associate professor of Earth and space sciences. Measuring and understanding changes in the Earth?s ice sheets over the past few decades, and predicting their future behavior are major challenges of modern glaciology. But it is important to view these changes in the context of what?s been happening naturally over centuries and millennia. This work establishes a background pattern of steady decline in the West Antarctic ice sheet.

Possible New Treatment Strategy for Deadly Brain Tumors

Despite advances in neurosurgery and radiation techniques, the prognosis for patients with intracranial glioma remains devastating. Now, researchers have identified a possible new treatment strategy for this common type of malignant brain tumor. Two studies funded in part by the National Institute of Neurological Disorders and Stroke (NINDS) show that, in a mouse model, neural stem cells (NSCs) can be used to deliver therapeutic agents capable of killing glioma cells and their migrating tumor cells.

Calorie restriction reduces age-related brain cell death

Trimming the waistline may not be the only reason to cut calories after the New Year: Doing so also may protect the brain from aging. In the first study to look specifically at the effects of life-long calorie-restricted diets on brain cells, University of Florida researchers determined certain proteins linked to cell death that naturally increase with age were significantly reduced in the brains of rats whose calories were limited. More important, they found the levels of a beneficial protein known to provide potent protection against neuron death were twice as high in older rats whose calories were restricted by 40 percent.

Designing a robot that can sense human emotion

Forget the robot child in the movie ?AI.? Vanderbilt researchers Nilanjan Sarkar and Craig Smith have a less romantic but more practical idea in mind. ?We are not trying to give a robot emotions. We are trying to make robots that are sensitive to our emotions,? says Smith, associate professor of psychology and human development.
Their vision, which is to create a kind of robot Friday, a personal assistant who can accurately sense the moods of its human bosses and respond appropriately, is described in the article, ?Online Stress Detection using Psychophysiological Signals for Implicit Human-Robot Cooperation.? The article, which appears in the Dec. issue of the journal Robotica, also reports the initial steps that they have taken to make their vision a reality.

New approach holds promise for reducing cocaine craving

New understanding of the changes in brain chemistry caused by chronic cocaine use has suggested a novel treatment that could reduce the intense craving that forms the core of cocaine addiction. “Our studies show that administration of an existing drug ? n-acetyl cysteine, which is used to treat cystic fibrosis and several other disorders ? reverses the changes in brain chemistry that appear to cause cocaine craving,” said David A. Baker, a post-doctoral fellow in the laboratory of Peter W. Kalivas at the Medical University of South Carolina.

Researchers explain how we detect the location of sound

The slightest turn of the head can significantly change the way a person or animal detects sound. A subtle tilt alters the angle at which high-frequency sound waves hit the ear, providing cues to localize the sound. To use those cues, the brain must put what it hears into the context of the position of the head. Until recently, scientists were not sure how this was done. Now researchers in Wisconsin appear to have the explanation. They have discovered that in the cochlear nucleus, the first sound-processing station in the brain, certain cells accomplish the job by integrating the two kinds of information, each of which travels along a distinct pathway.

Firefly molecule could quickly shed light on how well new drugs work

The process that makes fireflies glow bright in the summer night can also shed light on how well new medicines work, showing immediately whether the drugs are effective at killing cells or causing other effects. That’s the conclusion of a team of scientists who report that they have inserted the gene for a firefly’s glow-producing molecule into mice with cancer, and kept it from producing its telltale beacon of light until the cells started to die in response to cancer treatment.

Nicotine antagonist relieves depression in children with Tourette’s

A well-tolerated drug that blocks nicotine receptors in the brain appears to relieve depression and mood instability in children and adolescents with Tourette’s syndrome, a preliminary study has found. The multicenter, placebo-controlled study of the drug mecamylamine is published in the latest issue of the journal Depression and Anxiety. “These preliminary findings are consistent with anecdotal observations that mecamylamine stabilizes mood,” said lead author Douglas Shytle. “In addition, this is the first clinical evidence supporting the hypothesis that many antidepressants function, in part, by inhibiting nicotinic receptors.”

Physicist Says Market Crashes Predictable; Major Decline Due in 2003

Successfully predicting stock market swings is as futile as searching for the fountain of youth, some people believe. UCLA physicist and complex-systems theorist Didier Sornette is not among them. Sornette says he has found patterns that occur in market crashes dating back for centuries. Their statistical signatures are evident long in advance, he concludes. Sornette has developed algorithms ? based on sophisticated mathematics, statistical modeling techniques and collective behavior theory ? that enable him to analyze more than two dozen stock markets worldwide. Applying techniques of physics to economic data, he has developed a quantitative model that can predict the signatures of a coming stock market crash.

Stem cells used to track and destroy brain tumor cells

Researchers in Los Angeles have combined a special protein that targets cancer cells with neural stem cells to track and attack malignant brain tumor cells. Glioblastoma multiforme, or gliomas, are a particularly deadly type of brain tumor. They are highly invasive with poorly defined borders that intermingle with healthy brain tissue, making them nearly impossible to remove surgically without catastrophic consequences. Furthermore, cells separate from the main tumor and migrate to form satellites that escape treatment and often lead to recurrence.

Amputation, Reconstructive Surgery Have Same Outcomes for Severe Leg Injuries

Patients with severe leg injuries often face a difficult choice of whether to have multiple operations to repair their damaged limb or undergo amputation. With advances in medical technology, limb reconstruction has replaced amputation as the primary treatment at many trauma centers. But a new study finds that patients have similar outcomes regardless of the treatment. The study, coordinated by the Johns Hopkins Bloomberg School of Public Health, was conducted at the University of Maryland Shock Trauma Center and seven other trauma centers across the country. It found that while patients who undergo reconstructive surgery have a higher risk of complications, additional surgeries, and hospitalizations, they fared about the same as those patients who have a leg amputated. After two years, both groups had similarly high levels of disability and psychological distress, and only about half of the people in each group were able to return to work.

Scientists shed new light on the body’s internal clock

As mammals, our internal (circadian) clock is regulated by the patterns of light and dark we experience. But how that information is transmitted from the eye to the biological clock in the brain has been a matter of scientific debate. Scientists had suspected that a molecule called melanopsin, which is found in the retina, plays an important role. Now researchers have confirmed that melanopsin does indeed transmit light information from the eye to the part of the brain that controls the internal clock. According to the researchers, melanopsin may be one of several photosensitive receptors that work redundantly to regulate the circadian system.