2-A-E-5. The effect of static magnetic stimulation on motor learning and motor cortical excitability

Abstract

Recent studies reported the suppressive effects of static magnetic fields (SMFs) on human primary motor cortex (M1) possibly due to the deformed neural membrane channels. However, the neural mechanism of the excitability change at M1 and the suppressive effect on motor learning are not known yet. Here, we tested the biological effects of SMFs on human M1 and motor learning. We assessed whether SMFs can alter M1 function by using single and paired-pulse transcranial magnetic stimulation (TMS) in Experiment1, and whether it can interrupt the motor learning with keyboard tapping task in Experiment 2. We found the transient suppression of the cortico-spinal pathway and the transient enhancement of the short-interval intracortical inhibition (SICI), which might be related to GABA, immediately after compact magnet stimulation. Moreover, the consolidation of implicit motor memory induced by repetitive practice was obstructed by SMFs. The present results showed that the SMFs can produce the transient cortical functional change and the interruption of motor learning. It is suggested that the enhancement of SICI might be applied to treat neurological disorders associated with GABA dysfunction. Moreover, we discovered that the behavioral change in the implicit motor memory following SMFs.