[Abstract]ObjectiveTo observe the effects of enriched environmen(EE) on brain-derived neurotrophic factor (BDNF) in substantia nigra (SN) of senescence-accelerated prone mice, so as to explore the possible mechanism of EE in alleviating MPTP-induced damage and in protecting dopaminergic neurons in the SN. MethodsTotally 80 3-month old female SAMP8 mice were averagely assigned to EE and standard environment (SE) groups at random. After three months, the mice in each group were further divided into 2 subgroups at random: MPTP group and NS group (n=20). The MPTP groups received subcutaneous injection of MPTP, and the NS mice were treated with an equal volume of NS. At the seventh day, the mice were sacrificed for RT-PCR and immunohistochemistry staining. RT-PCR was used to examine BDNF mRNA expression and immunohistochemistry staining was used to examine BDNF-ir expression. MethodsCompared with SE+NS mice, EE+NS mice had significantly increased BDNF mRNA expression(P<0.01), and the number of BDNF-ir cell and COD values in SN were also significantly increased (P<0.01). Compared with SE+NS mice, SE+MPTP mice showed significantly decreased BDNF mRNA expression (P<0.001), and the number of BDNF-ir cells and the COD values in SN of mice were significantly decreased (P<0.01). Compared with SE+MPTP mice, EE+MPTP mice showed increased BDNF mRNA expression (P<0.01), and the number of BDNF-ir cells and the COD values in SN were significantly increased (P<0.01).MethodsEE can increase BDNF mRNA expression and BDNF-ir cell number in SN of SAMP8 mice, alleviating MPTP-induced SN damage.