Focused and deep brain magnetic stimulation using new coil design in mice

Deep brain transcranial magnetic stimulation (TMS) offers promising treatment for neurological disorders that originate from deeper regions of the brain, such as Parkinson's disease. Coils designed for the human head need significant redesigning to stimulate selective regions of the mouse brain for advanced TMS therapy analysis. We report a focused and deep brain TMS coil for mice that is based on a two coil configuration similar to the "Halo coil". A heterogeneous MRI derived head model of mouse was used to obtain an electric field of about 150 V/m in selective deeper regions of the brain. Focality of stimulation was quantified using the ratio of half value volume to half value of depth of electric field. A prototype of the final coil design was fabricated and characterized to compare simulated and physical magnetic field profiles.