In this project the PI will study how the primate retina processes and encodes visual images. The retina is an extraordinarily sophisticated optical image detector, converting a light image into a set of electrical signals, filtering these signals both spatially and temporally, and sending the output up the optic nerve to the brain. The output signals consist of multiple trains of electrical spikes organized in an exquisite and complex way, with more than 20 separate parallel pathways carrying visual information from the retina to the brain. In pilot experiments, a number of previously unknown, or poorly known, functional types of retinal neurons have been uncovered and in this research project the PI will answer the following questions: What roles do these cell types play in retinal processing? How do these neurons respond to different kinds of visual images? What information about the outside visual world do these cells communicate to the brain, and how is this information encoded? To answer these questions, a movie will be focused on the retinal input neurons (the rod and cone photoreceptors) and the electrical spikes generated by the retinal output neurons (including the new and poorly-known cell types) will be imaged and recorded by a dense two-dimensional array of over 500 microscopic electrodes. The output signals will then be correlated in space and time among themselves and with the input visual images to probe the neural code at the retina/brain interface. This research project will aid the development of future retinal prosthetic devices that are intended to restore some visual function in blind human patients with retinas damaged by photoreceptor disease. The project will also provide interdisciplinary research opportunities for undergraduate students, graduate students in both physics and biology.
