Relationship between Transcranial Magnetic Stimulation intensity and the growth rate of N27 Dopaminergic Neurons in vitro

Transcranial Magnetic Stimulation (TMS) is a non-invasive neuromodulation technique for the treatment of many neurological disorders. In 2008, TMS has been approved as a treatment for major depressive disorders by the US Food and Drug Administration (FDA). A time-varying magnetic field induces an electric field in the brain, therefore TMS has the ability to activate neurons in vivo. However, the effects of the magnetic fields on neurons in cell culture have not been investigated adequately. It has been found that transcranial magnetic stimulation promotes the proliferation of N27 cells in vitro. Based on these results, we investigated the effects of the magnetic fields generated by a biphasic stimulator with an air-cooled 70 mm double coil on a rat dopaminergic neurons cell line (N27) to explore the relationship between the stimulation intensity and the growth rate of N27 cells in vitro. The results of experiments showed that the difference in cell numbers between treatment group and control group is positively related to the stimulation intensity. It means the effects of magnetic stimulation on the proliferation of N27 cells is positively related to the magnetic field intensity.