AMPHETAMINE INDUCES HYPERMOTILITY IN MPTP-LESIONED MICE

Two strains of mice (NMRI and C57Bl/6) were treated with MPTP (within 8 h 4 x 30 mg/kg MPTP, IP) and motility was monitored 10 days later. A n acute administration of amphetamine (25 mg/kg or 10.0 mg/kg) or apom orphine (0.5 mg/kg or 5.0 mg/kg) led to hypermotility and a dose-depen dent increase of stereotyped behavior. Immunocytochemical investigatio ns indicated a substantial loss of tyrosine-hydroxylase immunoreactivi ty in the basal ganglia which was accompanied by a 15% increase of H-3 -spiroperidol binding to a striatal membrane preparation. No differenc e was found in biochemical and behavioral measures between both mice s trains. Thus, MPTP-induced lesions in mice are probably followed by a denervation-like supersensitivity of the dopaminergic system, which mi ght account for the finding that despite a severe degeneration of dopa minergic terminals amphetamine induces hypermotility. Copyright (C) 19 97 Elsevier Science Inc.