Parkinson's is the second most common neurodegenerative disease affecting older people in the United States and is characterized by a loss of dopamine in the basal ganglia portion of the brain.
"Our research indicates that the loss of dopamine seems to cause connections in the brain to reorganize. This affects the brain's ability to communicate effectively with body parts, for example, the ability to respond to stimuli from the body in order to control body movements," explained Mark West, a behavioral neuroscientist and professor in the department of psychology at Rutgers' Faculty of Arts and Sciences-New Brunswick.
His findings are presented in the study "Dopamine depletion causes fragmented clustering of neurons in the sensorimotor striatum: Evidence of lasting, altered responsiveness to corticostriatal input" in the Journal of Comparative Neurology (volume 452, issue 1, Oct. 7, 2002).
West and his research team studied rats and produced the first-ever microelectrode functional map of the sensorimotor portion of the basal ganglia in a Parkinsonian brain. They found that clusters of neurons in the basal ganglia that control specific movements became smaller in size when dopamine deprived.
"The neurons weren't shrinking or moving closer together; they were still distributed about the same as a normal brain," explained West. "But evidence showed that around the edges of the clusters some of the neurons changed their responsiveness and were thereby excluded from their original clusters. Some remained isolated and others became affiliated with nearby clusters.
"For example," he continued, "a fore-limb cluster neuron could become affiliated with a h
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Contact: Stacey Hersh
shersh@ur.rutgers.edu
732-932-7084
Rutgers, the State University of New Jersey
3-Sep-2002