Abstract: Objective:To explore the effects of repeated transcranial direct current stimulation (tDCS) on the depression behaviors in the rat models of Parkinson' s disease (PD),and to clarify the neurochemical mechanism of tDCS in affecting the PD-related depression behaviors. Methods:A total of 32 rats were randomly divided into sham operation group,PD group,anodal repeated tDCS group and cathodal repeated tDCS group,8 rats in each group.Except sham operation group,the rats in other groups were used to establish the PD models.The depression behaviors immobility time and sucrose consumption of the rats in various groups were observed by forced swimming test and sucrose preference test.The monoamine levels in medial prefrontal cortex (mPFC) and raphe nuclei (RN) of the rats in various groups were assessed by HPLC-electrochemistry method. Results: Compared with PD group,the immobility time in anodal repeated tDCS group and cathodal repeated group was significantly decreased (P<0.05 or P<0.01);the sucrose consumption in anodal repeated tDCS group was significantly increased (P<0.05),but no significant change was observed in cathodal repeated tDCS group (P>0.05).Compared with PD group,the levels of dopamine (DA) and 5-hydroxytryptamine (5-HT) in mPFC and RN of the rats in anodal repeated tDCS group were significantly increased(mPFC:P<0.05 or P <0.01; RN:P<0.01); the level of 5-HT in mPFC of the rats in cathodal repeated tDCS group was significantly increased (P<0.05). Conclusion:The repeated tDCS,especially the anodal repeated tDCS,can alleviate the depression behaviors in the rat models of PD,and their mechanisms may be related to the increasing of the monoamine levels in the related brain regions.

Key words: monoamine, repeated transcranial direct current stimulation, Parkinson’s disease, depression