Circuit Engagement in Prosthetically Driven Retina

University Of California, San Diego, La Jolla CA

Investigators

Linked publications & trials

Abstract

PROJECT SUMMARY Blindness caused by photoreceptor death, as in Retinitis Pigmentosa and Age related Macular Degeneration, is among the leading causes of irreversible blindness in the world today. Retinal prosthetics are currently the only vision restoration therapy available for these patients but results so far have been modest. To design more effective retinal prosthetic devices, we need a better understanding of how prosthetic stimulation activates diseased retinal circuitry to perform basic visual computation. The premise of this proposal is based on the observation that inhibition is an integral part of retinal signaling yet remains poorly understood in the context of retinal degeneration and vision restoration. This leaves us with an incomplete understanding of how retinal degeneration changes visual processing circuits. Here we will identify how inhibitory signaling is altered by retinal degeneration and determine how these changes alter the processing of prosthetic visual information during clinically relevant patterns of electrical stimulation. This proposal is innovative, because we use a unique combination of single cell electrophysiology techniques, combined with custom fabricated multielectrode arrays consisted with current devices used in clinical trials. The results from this proposal will be significant and will: 1.) Determine optimal stimulation strategies to restore vision in a range of vision restoration technologies. 2.) Uncover basic physiological mechanisms that determine how spared retina responds to electrical stimulation, and 3.) Determine how prosthetics can engage basic computational circuitry in diseased retina to extract temporal contrast information from spatiotemporal patterns of electrical stimulation. These experiments will produce needed insight into the fundamental mechanisms underlying early visual computation and guide strategies to improve the design and execution of retinal prosthetic devices. The long-term goal of this work is to improve the design and implementation of retinal prosthetics for vision restoration, ultimately improving the quality of life for a broad patient population.