Chronic repetitive transcranial magnetic stimulation increases hippocampal neurogenesis in rats.

Aim:  While the underlying therapeutic mechanisms of repetitive transcranial magnetic stimulation (rTMS) treatment for depression remain unclear, recent animal studies have suggested that hippocampal neurogenesis might be required for the effects of antidepressant treatments including antidepressant drugs and electroconvulsive therapy. The aim of this study was to examine chronic rTMS effects on hippocampal neurogenesis in rats. Methods:  Using a 70-mm figure-of-eight coil, the stimulating parameters were set to 25 Hz and 70% of the rTMS device's maximum power. For 14 consecutive days, bromodeoxyuridine (BrdU) and 1000 pulses of rTMS were administered daily. Cell proliferation in the dentate gyrus was examined with immunohistochemistry. Results:  In the rTMS-treated group, BrdU-positive cells were significantly increased in the dentate gyrus. Conclusion:  Our results suggest that hippocampal neurogenesis might be involved in the antidepressant effects of chronic rTMS.