Objective   To investigate the effects of exercise and complex environment on lipopolysaccharide (LPS)-induced dopaminergic neuron death in the substantia nigra of midbrain.   Methods C57BL/6 mice were divided into control group, LPS group, LPS+swimming group and LPS+complex environment group, with 7 mice in each group. The mice in the LPS group were injected with LPS into the brain to establish an inflammatory model of Parkinson ’s disease and lived in cages for 2 weeks. Mice in LPS+swimming group were forced to swim for 15 minutes every day for 2 weeks after modeling. The mice in the LPS+complex environment group were placed in a complex environment for 2 weeks after modeling. The control group mice were not treated. After 14 days of modeling, behavioral experiments such as footprint, open field and rotating rod were performed on each group of mice to detect the autonomous exercise ability, exercise balance ability and depression level of mice. The expressions of tyrosine hydroxylase (TH) in substantia nigra was detected by immunohistochemical staining and Western blotting. The expressions of brain-derived neurotrophic factor (BDNF), Caspase-3, interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α(TNF-α) in the substantia nigra of the midbrain were detected by Western blotting. The transcription levels of IL-1β, IL-6 and TNF-α in substantia nigra were detected by RT-PCR.   Results  Compared with the control group, the exercise ability and balance ability of mice in LPS group, LPS+swimming group and LPS+complex environment group decreased, the depression level increased（P＜0.001）, the number of TH positive neurons and BDNF protein decreased significantly（P＜0.001）, and the contents of Caspase-3, IL-1β, IL-6 and TNF-α increased significantly（P＜0.001）. Compared with the LPS group, the exercise ability and balance ability of the mice in the LPS+swimming group and the LPS+complex environment group were restored, the depression level decreased significantly（P＜0.01）, the survival number of TH positive neurons and the content of BDNF increased significantly（P＜0.01）, Caspase-3, IL-1β, IL-6 and TNF-α  reduced significantly（P＜0.01）, and the phenomenon in the LPS+complex environment group was more significant.   Conclusion Exercise and complex environment can inhibit LPS-induced central nervous system inflammation in mice, thereby reducing damage to midbrain substantia nigra neurons, and the inhibitory effect of LPS+complex environment group is more significant.

Movement, Complex environment, Inflammation, Dopaminergic neuron, Lipopolysaccharide, Behavioral experiment, Western blotting, Mouse