DURIP SUPER RESOLUTION ADAPTIVE OPTICS OPHTHALMOSCOPE FOR REVEALING THE RETINAL CODE
Abstract
A team of scientists and engineers at the University of Rochester will construct a novel optical instrument with the capability to transform our understanding of the neural code the retina uses to send the retinal image to the brain. Understanding this code is critical for understanding vision. The neural signal from the retina is conveyed to the brain, not by one kind of neuron, but by more than 20 different classes of retinal ganglion cells (RGCs). RGCs are the output neurons of the retina whose axons form the optic nerve connecting the retina to more central visual areas in the brain. The signal carried by each of these RGC classes is distinct from each of the others, reflecting different computations by the retina that provide the brain with more than 20 separate neural images for subsequent processing. Why the retina is organized in this way is not at all clear, in part because we have almost no direct information about the contribution each RGC class makes to visual perception. The instrument we will construct with DURIP support will allow a new paradigm that will provide the first direct measurements of the role of RGC classes in vision. The instrument is a custom-built fluorescence ophthalmoscope incorporating free form optics, adaptive optics, and super resolution microscopy. These features will provide sufficient resolution to classify individual RGCs in the living monkey fovea based on their anatomy and physiology. This morphology is typically observed in retinas that have been removed from the eye, but the proposed ophthalmoscope will allow us to obtain images in the living eye, a critical advantage enabling psychophysical experiments where the identified cells can be directly stimulated to understand their role in visual perception. To conduct these psychophysical experiments, the ophthalmoscope will not only be able to image individual RGCs, it will also deliver highly focused spots of light to them. Using an injection into the eye before the psychophysical experiments, RGCs will express a light sensitive, optogenetic actuator, allowing single RGCs to be directly stimulated. The effect on vision of stimulating single RGCs of known class will then be measured with psychophysical experiments in awake behaving monkeys. These measurements will clarify the neural code the retina uses to transmit information to the brain and the advantages of separating the retinal image into more than 20 neural images. The vast majority of previous physiological measurements made of RGCs have been made in the peripheral retina due to technical limitations involving recording from the fovea, where primate color and spatial vision is best. Our experiments will provide some of the first measurements of the neural circuits that mediate the performance of foveal vision in the primate. These results may inform the design of man-made smart vision systems, heads up displays, and augmented and virtual reality devices that have the potential to augment human visual performance.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502210044
Entities
People
- David R. Williams
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Rochester