An amphibian model for developing and evaluating retinal prostheses

The current project seeks to address the problem of constructing models with which to guide the development and evaluation of retinal prosthesis designs. In particular, the efforts described in this paper are intended to develop a more complete understanding of how electrical stimulation of ganglion cells by external electrodes interacts with retinal surface tissues, and how specific stimuli are encoded by the retinal and optic nerve processing systems. Toward this end, novel surgical techniques, optic tecturm recording from live animals, correlational analysis, and systematic electrophysiological recording of stimulation are utilized. Microsurgical methods for providing a repeatable, chronic implantation of stimulating prostheses have been developed. An optoelectronic processor capable of reliably encoding wavelength-dependent intensity information, including sensitivity changes with light adaptation has also been constructed.