Foot motor cortex and hippocampus depth comparison
The proposed methodology is novel in orienting TMS to the hippocampus to combine hippocampal endogenous activity with spTMS. The comparison between foot M1 and the hippocampus determined that the depth of both brain regions is comparable, and that the technique is applicable to both hemispheres. Moreover, we designed a combined-stimuli protocol to apply an intensity equivalent to 120% of the RMT of the foot M1. With these parameters, it is highly probable that TMS activates the hippocampal nervous cells located at a depth equivalent to the M1 foot representation. Furthermore, the foot M1 and hippocampus have comparable cytoarchitecture: both areas are populated by pyramidal neurons and part of their arrangement is parallel to the contiguous scalp, following a columnar distribution along the cortical gyrus [