Microtubules, intracellular highways that transport dopamine to the brain area that controls body movement, are the crucial target, they report.
Damage to microtubules prevents dopamine from reaching the brain's movement center, causing a back-up of the neurotransmitter in the transport system, the researchers found. The backed-up dopamine accumulates in the body of the neuron and breaks down, causing a release of toxic free radicals, which destroy the neuron.
The study appeared in the Aug. 9 issue of the Journal of Biological Chemistry.
"This study shows how an environmental toxin affects the survival of dopamine neurons by targeting microtubules that are critical for the survival of dopamine-producing neurons," said Jian Feng, Ph.D., assistant professor of physiology and biophysics in the UB School of Medicine and Biomedical Sciences and senior author on the study.
"Based on these findings, we have identified several ways to stabilize microtubules against the onslaught of rotenone. These results ultimately may lead to novel therapies for Parkinson's disease."
At least 500,000 people are believed to suffer from Parkinson's disease in the United States, and about 50,000 new cases are reported annually, according to the National Institutes of Health. These figures are expected to increase as the population ages: The average age of onset is about 60. The disorder appears to be slightly more common in men than women.
Feng and colleagues in the Department of Physiology and Biophysics have concentrated their research on the cellular mechanisms of the disease.