Alterations of the central noradrenergic system in MPTP-induced monkey parkinsonism.

Alterations of the coeruleo-cortical adrenergic system in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced monkey parkinsonism were examined through neuropathological observation and radioreceptor assay. Neuronal degeneration was found not only in the substantia nigra but also in the locus coeruleus of all the MPTP-treated monkeys. From radioreceptor assay, decreases of alpha 1 and alpha 2 receptors in the parietal and temporal cortices were observed in parkinsonian monkeys. In addition, beta receptors increased in the temporal cortex. These changes in monkey parkinsonism are very similar to those in human Parkinson's disease.