Neuronal responses by transcranial magnetic stimulation in cortex

Transcranial magnetic stimulation (TMS) is a technique increasingly used as a non-invasive diagnostic and experimental tool in electrophysiology. TMS has advantages over electrical stimulation in its ability to stimulate deep nerves and the brain without discomfort. This noninvasive stimulation of the nervous system also seems to offer new opportunities for the investigation of neuronal activity. In this paper, using a transcranial magnetic stimulation technique in combination with microelectrode recording in the cortex of the mongolian gerbil, evoked trains of complex spikes were studied. It was found that the spike rate and duration of the neuronal responses depended on the magnetic stimulus frequency. This suggests that transcranial magnetic stimulation is a useful technique for studying neuronal activities non-invasively.