INCREASED DOPAMINE TURNOVER IN THE PUTAMEN AFTER MPTP TREATMENT IN COMMON MARMOSETS

The differences in dopamine turnover rate between the putamen and the caudate nucleus in the striatum lesioned by a neurotoxin 1-methyl-4-ph enyl-1,2,3,6-tetrahydropyridine (MPTP) were studied in the common marm oset, a small New World monkey. Systemic administration of MPTP damage d equally and dose-dependently nigrostriatal dopaminergic neurons proj ecting both to the caudate nucleus and the putamen. The compensatory i ncrease of dopamine turnover, however, occurred more prominently in th e putamen than in the caudate. The neural connection and function of t he caudate nucleus and the putamen have been differentiated anatomical ly or physiologically. The compensatory increase of dopamine turnover rate is another different aspect of functions between the caudate nucl eus and the putamen. Dopaminergic neurons projecting to the putamen sh owed more prominent cell loss than those projecting to the caudate in Parkinson's disease or related disorders. The selective augmented turn over rate of lesioned dopaminergic neurons might be, at least partly, involved with selective degeneration of nigrostriatal neurons projecti ng to the putamen. (C) 1997 Elsevier Science B.V.