Influence of Morphological and Electrophysiological Parameters on Retinal Ganglion Cells Threshold under Temporal Interference Stimulation

Transcorneal electrical stimulation (TES) has been proved to be able to provide neuroprotection effect to delay retinal degenerative diseases. However, the diffuse electric field and subthreshold stimulation current delivered by the conventional TES cannot accurately stimulate retinal neurons. A more recently developed temporal interference (TI) stimulation approach has demonstrated the capability of generating a more localized electrical field near the target neurons, suggesting its promising performance in localized retinal stimulation. The characteristics of retinal ganglion cell (RGC) activation are not only related to the electric field distribution, but also related to the morphological and electrophysiological characteristics of RGCs itself. This study investigated the effect of multiple RGC morphological and electrophysiological properties on the RGC activation threshold under TI stimulation. Our simulation suggested that RGC activation threshold was most affected by sodium channel conductance distributed in high sodium channel band (SOCB) and less affected by dendritic field size, dendritic field depth, and SOCB length. RGC activation threshold decreased with the increment of SOCB conductance and slightly decreased with the increment of dendritic field depth and SOCB length, while slightly increased with the increment of dendritic field size. This study provides new knowledge about the spatial responsive characteristics of RGC activation under TI stimulation.