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New Clues to Development of ALS (Lou Gehrig’s Disease)
Johns Hopkins scientists and colleagues say they have evidence from animal studies that a type of central nervous system cell other than motor neurons plays a fundamental role in the development of amyotrophic lateral sclerosis (ALS), a fatal degenerative disease. The discovery holds promise, they say, for identifying new targets for interrupting the disease's progress. In a study described online on March 31, 2013 in Nature Neuroscience, the researchers found that, in mice bred with a gene mutation that causes human ALS, dramatic changes occurred in oligodendrocytes — cells that create insulation for the nerves of the central nervous system — long before the first physical symptoms of the disease appeared. Oligodendrocytes located near motor neurons — cells that govern movement — died off at very high rates, and new ones regenerated in their place were inferior and unhealthy. The researchers also found, to their surprise, that suppressing an ALS-causing gene in oligodendrocytes of mice bred with the disease — while still allowing the gene to remain in the motor neurons — profoundly delayed the onset of ALS. It also prolonged survival of these mice by more than three months, a long time in the life span of a mouse. These observations suggest that oligodendrocytes play a very significant role in the early stage of the disease. "The abnormalities in oligodendrocytes appear to be having a negative impact on the survival of motor neurons," says Dwight E. Bergles, Ph.D., a co-author of the article and a professor of neuroscience at the Johns Hopkins University School of Medicine.