Autoradiographic Distributions of Neurotransmitter Receptors in the Brain of Patients with Parkinson’s Disease and MPTP-induced Monkey Parkinsonism

Parkinson’s disease is a slowly progressive degenerative disorder which is pathologically characterized by neuronal loss of the substantia nigra. Biochemically, deficiency of dopamine in the striatum resulting from degeneration and loss of dopaminergic neurons in the substantia nigra has been confirmed. In addition, from experiments using autopsied human materials [1–6], abnormalities have been reported in the dopaminergic as well as in the following systems: acetylcholine, GABA, serotonin, noradrenaline, and peptide-containing neurons. Recently, it was discovered that 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a by-product in the synthesis of MPPP (1-methyl-4-phenyl-4-propionoxy-piperidine), is selectively toxic to the zona compacta of the substantia nigra [7]. In this paper, we report on observed distributions of neurotransmitter receptors in brains of patients with Parkinson’s disease and those of primate models with MPTP-induced parkinsonism.