Abstract
Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf
animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also
inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats
that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of
Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical
and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.
