From New Orleans, at the annual meeting of the Society for Neuroscience
Epidemiologists have long suspected that exposure to some pesticides promotes the development of Parkinson’s disease. Basic chemistry supports that view: The molecular structure of MPTP, a toxic compound that in animals causes a condition similar to Parkinson’s disease, is related to that of several pesticides.
A study on rotenone, a plant-derived pesticide commonly used in organic gardening, now adds more evidence for the connection. Prolonged administration of rotenone into the jugular veins of rats produces tremors, an unsteady gait, and other symptoms comparable to those of Parkinson’s disease, J. Timothy Greenamyre of Emory University in Atlanta and his colleagues reported in New Orleans and in the December Nature Neuroscience.
The researchers also found that the pesticide kills the same subgroup of brain cells that normally dies during the course of disease. Furthermore, brain cells of the rotenone-treated rats develop the same abnormal protein masses that mar the brain cells of people with Parkinson’s disease.
While people probably don’t receive as massive an exposure to rotenone as the tested rats did, the research raises questions about the safety of that pesticide and others. “The new study will revitalize the search for environmental toxins, including other pesticides, that may contribute to the etiology of [Parkinson’s] disease,” Benoit I. Giasson and Virginia M.-Y. Lee note in a commentary in the December Nature Neuroscience.