ScienceCache

Vol. 183
Oct. 8, 2004

UNDER THE SURFACE, THE BRAIN TEEMS WITH UNDISCOVERED ACTIVITY
There’s an old myth that we only use 10 percent of our brains, but researchers have found that roughly 80 percent of our cognitive power may be cranking away on tasks completely unknown to us. Curiously, this clandestine activity does not exist in the youngest brains, leading scientists to believe that the mysterious goings-on that absorb the majority of our minds are dedicated to subconsciously reprocessing our initial thoughts and experiences. “We found neural activity that frankly surprised us,” says Michael Weliky, associate professor of brain and cognitive sciences. Weliky made the finding by studying ferrets as they watched the reality-stretching film The Matrix. He found that adult and young ferrets seemed to process the images very differently. Placing the ferrets in a darkened room revealed that older ferrets’ brains were still humming along as if they were processing visual information. Since this activity was absent in the youngsters, Weliky and his colleagues were left to wonder: What is the visual cortex so busy processing when there’s no image to process? “This means that in adults, there is a tremendous amount of real-world processing going on--80 percent--when there is nothing to process,” says Weliky. “We think that if you’ve got your eyes closed, your visual processing is pretty much at zero, and that when you open them, you’re running at 100 percent. This suggests that with your eyes closed, your visual processing is already running at 80 percent, and that opening your eyes only adds the last 20 percent. The big question here is what is the brain doing when it’s idling, because it’s obviously doing something important.” The team reported the research recently in the journal Nature.
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CANCER CENTER STUDIES LONG-TERM RISKS OF CHILDHOOD TREATMENT
Doctors are trying to improve childhood cancer treatments so that kids are less likely to develop heart problems or second malignancies later, as a result of radiation therapy. Physicians from the James C. Wilmot Cancer Center presented two research projects on the subject at the American Society for Therapeutic Radiology and Oncology annual meeting in Atlanta this week. In one study of 277 adults who had had cancer as children, radiation oncologist Ronald Hale found that heart damage corresponded with larger doses of radiation; damage included left ventricle shrinkage, a thinning of the LV wall, and a regurgitation of blood flow in the valves. In addition, some childhood cancer survivors are at increased risk for coronary artery disease. In another study, Louis Constine, professor of radiation oncology and pediatrics, found that survivors of childhood Hodgkin lymphoma are at risk for second malignancies, and the risk increases with higher radiation doses. He studied the cases of 930 children, under 18 years old, who were treated between 1960 and 1990. Overall, the childhood cancer survivors were 14 times more likely than the general population to develop a second cancer. Also, breast cancer was more prevalent among females who received higher radiation doses as children, the study found.
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UROLOGISTS STUDY NEW DNA TEST FOR BLADDER CANCER RECURRENCE
James P. Wilmot Cancer Center urologists are joining a national effort to test a new non-invasive detection method for the recurrence of bladder cancer – one of the most common forms of cancer to return after treatment. Scientists at 12 sites across the nation will examine genetic changes in DNA obtained through urine samples from patients during the three-year study. Frequent surveillance of bladder cancer patients is critical, but current procedures have shortcomings, oftentimes either failing to detect early tumors or being very invasive and unpleasant. The new test, created by the Early Detection Research Network of the National Cancer Institute, looks to improve upon these weaknesses. The test relies on the analysis of microsatellite DNA, which are repeating units of one to six nucleotides found throughout human chromosomes. These repeating regions are frequently mutated in tumors. Early studies have shown this non-invasive analysis can have over 90 percent accuracy. “It's the first study testing high-speed DNA technology to detect bladder cancer. If the results are positive, it will make large use of this test for monitoring this disease, and even screening, feasible,” says urologist Edward M. Messing, who is leading the Rochester portion of the study.
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ROCHESTER TO LEAD STUDY ON DEPRESSION IN PATIENTS WITH PARKINSON’S
A University of Rochester neurologist is heading a national research study to test the effectiveness of anti-depressants in treating some of the symptoms of Parkinson’s disease. Parkinson’s disease typically brings to mind symptoms such as tremors and slow movement, but researchers have found that nearly half of all Parkinson’s patients also suffer from depression. While it might seem natural that someone who has a disease such as Parkinson’s might become depressed, it’s not so simple, says neurologist Irene Richard, who leads the study. “Many patients assume that’s it’s normal to feel this way. They might say, ‘If you had Parkinson’s disease, you’d feel this way too.’ That’s not true. If you treat the depression, they’ll still have the other symptoms of the disease, but they feel better. It’s very treatable,” says Richard. “People diagnosed with other serious diseases that may also be disabling, such as rheumatoid arthritis, aren’t nearly as likely to become depressed.” Richard’s study will evaluate common anti-depressant medications paroxetine and venlafaxine at treating the depression that patients experience. Richard says that until now, there hasn’t been a large placebo-controlled study to see how well anti-depressant medications actually work in patients with Parkinson’s. The disease wreaks havoc in the brain and may cause such medications to work differently than they do in healthy people. The study will include 228 patients at 15 sites around the nation. The four-year, $4 million study is being funded by the National Institute of Neurological Disorders and Stroke.
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