Electrical Stimulation of Spiral Ganglion Cells in the Human Cochlea: A 3D Model

Electrical stimulation of auditory nerve fibers by cochlear implant electrodes has been an approved clinical practice to restore the hearing sensation in profoundly deaf people. Profound deafness is largely attributed to the loss of hair cells and subsequent decay of peripheral processes of auditory nerve fibers in the cochlea. In such pathological condition, spiral ganglion cells (SGN) which are intact with central process of auditory nerve fibers in Rosenthal’s canal play a crucial role to generate and propagate the action potentials in response to the applied electric field. In this paper we describe the SGN response to the applied electric field by a bipolar electrode. Unlike the other existing models, we have considered the geometry of SGN and cochlea with essential approximations to discuss the signal propagation through the SGN at basal region of the cochlea via appropriate visualizations. This kind of a detailed 3D model serves as a useful tool to have a deeper understanding about the functionality of cochlear implant electrodes.