Investigation of Coil Designs for Transcranial Magnetic Stimulation on Mice

Transcranial magnetic stimulation (TMS) is a non-invasive, surgery-free, and safe treatment for major depressive disorder. There is a need to develop coils, which can stimulate deep brain regions for the treatment of other neurological disorders, such as Parkinson's disease. Stimulation of the deep brain regions cannot be directly tested on human subjects without successful animal trials. In this paper, seven mouse TMS coils were compared and their electric and magnetic fields in the brain were calculated. Coils, such as "Slinky" coil and "V" coil, stimulate small and outer layers of the mouse brain, while "Animal Halo" coil stimulates similar to 90% of the mouse brain. This comparison between the coils enables researchers to choose the right coil according to their need, such as the depth of penetration or the focality of brain region to be stimulated.