nigrostriate bundle


nigrostriate bundle

A dopaminergic axon tract from the substantia nigra to the striatum in the basal ganglia. Activation of the nigrostriate bundle inhibits the striatum, which normally lowers the activity of motor programs. In Parkinson's disease, neurons in the substantia nigra are damaged, and their effect on the striatum is reduced; the result is unchecked activity of the striatum and an excessive damping of motor programs, i.e., hypokinetic behavior. Synonym: nigrostriatal fibersSee also: bundle