In C57 black mice, MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) (30 mg/kg X 2, 20 mg/kg X 15, 30 mg/kg X 15, or 35 mg/kg X 1) depleted DA in both striatum and accumbens but not in frontal cortex, hypothalamus and retina. DA decreases were more pronounced in striatum than in accumbens, were maximal at 2 days, partially reversed later but persisted up to 30 days after treatment. DA depletions in nigra were smaller earlier and maximal later. The study suggests that, in mice, MPTP damages nigrostriatal and mesolimbic projections but spares other DA neurons.