Effects of MPTP on spatial learning ability/memory and dopaminergic neurons in Nigra of senescence accelerated-prone 8 mice

Objective:To observe the effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)on the spatial learning ability/memory and dopaminergic neurons in the Nigra of senescence accelerated-prone 8(SAMP8)mice.Methods:Three-month old male SAMP8 mice were injected with MPTP(36 mg/kg,s.c.)for 5 days,and animals in the control group were injected with NS(36 ml/kg,s.c.)in the same manner.Morris water maze was used to examine the searching strategy,seeking-platform latency,and the swimming time in the aimed quadrant.Immunohistochernistry was used to observe the changes of TH-ir positive neurons in substantia nigra.Results:The number of TH-ir neurons in substantia nigra pars compacta was significantly reduced in MPTP group compared with the control group(P0.01).Morris water maze showed that the searching strategy of animals in MPTP group was worse than in the control group,with the seeking-platform latency of MPTP mice significantly prolonged(P0.01),the time spent in the aimed quadrant significantly decreased(P0.01)and time in the opposite quadrant significantly prolonged(P0.05).Conclusion:MPTP can cause damage to the dopaminergic neurons in the substantia nigra of SAMP8 mice,which is subsequently followed by deficit in the spatial learning and memory in the animals.