A comparative study of light and electrically evoked response of retinal ganglion cells

Understanding of the evoked neural discharges from retinal tissues is vital for designing of any retinal prosthesis. In this study, retinal ganglion cell activity to light and electrical stimulus is recorded using multielectrode arrays. For an effective epiretinal prosthetic device, the electrical stimulus through the prosthesis should be able to evoke responses similar to those of light response in normal condition. This pilot study was intended to design the experimental protocol for in-vitro retinal stimulation. Light and electrical stimulus of same duration to normal goat retina evoked different responses. Electrical stimulus produces greater number of spikes as compared with light response of same duration. With the experimental set up and the analysis technique presented here, stimulation parameters such as frequency of input pulse, amplitude, type of pulse required to generate responses close to that of light response can be optimized.