Effect of repetitive transcranial magnetic stimulation on the improvement of behavior and hippocampus BDNF expression in chronic stress-induced depression rats / 中国神经精神疾病杂志

ABSTRACT

Objective To explore the effects of repetitive transcranial magnetic stimulation (rTMS) on the improve?ment of depressive behavior and the hippocampus brain derived neurotrophic factor (BDNF) expression in chronic stress-induced depression rats. To further investigate the possible molecular mechanism of rTMS treatment for depres?sion. Methods Forty male Sprague-Dawley rats of SPF grade were randomly divided into the blank control group (n=8) and the stress-induced group (n=30). Singly housing and chronic unpredictable mild stress (CUMS) were used to induce the depression model in stress-induced group. Twenty-four model rats were divided into three groupsmodel group (with no further treatment), rTMS group (receiving 10 Hz rTMS intervention for 3 weeks) and shame group (receiving pseudo TMS treatments for 3 weeks). Weight measurement, sucrose consumption test and open-field test were used to assess the behavior changes. The rat hippocampal CA3 area of BDNF positive staining cell number and expression levels of BDNF mRNA in hippocampus were examined after intervention. Results The weight reduction rate, score of sucrose consump?tion test and the score of open field test were significantly higher in rTMS group than in model group (P<0.05). The num? ber of BDNF staining positive cells in the hippocampal CA3 area was lower in model group and shame group than in the blank control group whereas was higher in the rTMS group than in the model group (P<0.01). Compared with the model group, the BDNF mRNA relative expression was significantly increased in the hippocampus of rTMS group (P<0.01). Conclusion rTMS can improve depressive behaviors of CUMS rats probably through the increase in expression of BDNF in the hippocampal neurons and neuronal regeneration.