DURHAM, N.C. -- In a finding that contradicts current theories behind Parkinson's disease, neuroscientists at Duke University Medical Center have discovered in mice that critical nerve cells fire all at the same time and thus overwhelm the brain's ability to control the body's movements.
Previously, scientists had thought that the abnormal body movements characteristic of Parkinson's resulted from nerve cells in a specific brain region called the motor cortex firing at a decreased rate, though still in an ordered manner.
"Imagine an orchestra playing a beautiful symphony, with each instrument playing a different part, but in harmony. That is the way the brain normally works, with nerve cells sending different but coordinated signals throughout the brain," said senior study investigator Miguel Nicolelis, M.D., Ph.D., Anne W. Deane Professor of Neuroscience. "We found that in an animal model of Parkinson's, nerve cells seem to fire all at the same time, rather than in harmony. It's like having all instruments playing the same note over and over again at the same time during the symphony, rather than the different instruments playing at different times."
Although the researchers made their discoveries in genetically engineered mice, they believe the same processes may occur in humans.
The findings may help researchers to better understand Parkinson's disease and to develop new therapeutics for the debilitating disorder, said lead study investigator Rui Costa, D.V.M., Ph.D., chief of the section of in vivo neural function at the National Institutes of Health, who launched this study as a postdoctoral fellow in Nicolelis' laboratory.
"Therapeutic interventions that restore the normal synchrony of these neurons in the brain may potentially be beneficial in treating Parkinson's disease," Costa said.
The researchers published the findings in the Oct. 19, 2006, issue of the journal Neuron. The work was funded by the N
Contact: Marla Vacek Broadfoot
Duke University Medical Center