Motor function in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mouse.

Motor function was assessed by use of a swim test in C57 Black mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Thirty minutes after the last MPTP injection significant motor impairment was observed while striatal dopamine was reduced to 13.9% of control levels. At 24 h and 7 days post MPTP injection dopamine levels were still reduced to 17.3% and 26.4% of control values but swimming abilities of the mice were unimpaired. Histofluorescence of catecholaminergic neurons confirmed the presence of catecholamine depletion but showed little evidence of neuronal destruction. The use of MPTP as a non-invasive means of nigrostriatal dopamine depletion in rodents and higher animals allows a re-evaluation of the role of the dopaminergic system in the modulation of movement.