Changes of Locomotor Activity and Biogenic Amines by 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine in C57BL/6 Mice

ABSTRACT

The neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in rodents was investigated by measuring the locomotor activity and the changes of brain biogenic amines in MPTP-treated C57BL/6 mice. The mice showed a typical curved spine posture 24 hours after MPTP treatment. Total locomotor activity was reduced and the ratios of stereotyped activity/total locomotor activity were increased 24 hours after MPTP treatment. However no significant changes were observed 7 days after MPTP treatment. MPTP-induced changes of biogenic amines were evident only in corpus striatum, not in frontal lobe, midbrain and hippocampus; the levels of dopamine, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were reduced by 94%, 76.3% and 60.2% after 24 hours, and 81.9%, 61.3% and 26.1% after 6 days compared to control values respectively. The ratios of DOPAC/dopamine, HVA/dopamine and HVA/DOPAC were increased 24 hours and 7 day after MPTP treatment compared to control valuse in corpus striatum, but the degree of the 7 days was less than the 24 hours. The ratios of 5-HIAA/5-HT were incresed 24 hours and 7 days after MPTP treatment in corpus striatum, but there were no significant changes in the levels of 5-hydroxyindoleacetic acid (5-HIAA) and 5-hydroxtryptamine (5-HT). In conclusion, MPTP produced parkinsonism-like behavioral and biochemical changes in C57BL/ 6 mice.