Chichilnisky Lab
Systems Neurobiology and Sloan-Swartz Center
The Salk Institute

Valerie Uzzell

The Salk Institute, 10010 North Torrey Pines Road, La Jolla, CA 92037-1099 (858) 453-4100 x1536 (858) 455-7933 uzzell@salk.edu

Spike Timing Precision in Primate Retinal Ganglion Cells:

Recent studies have indicated that light responses of retinal ganglion cells (RGCs) in several species can exhibit spike timing variability as low as a few milliseconds in response to repeated stimuli. We are examining whether primate RGC spike trains exhibit similar timing precision, and whether the observed precision can be explained by a simple model of spike generation.

Pooling of rod inputs and limits to sensitivity in primate retinal ganglion cells:

Based on a combination of behavioral and physiological measurements, it has been suggested that behavioral detection of dim flashes is limited by noise in rod photoreceptors--in particular by the rate of spontaneous isomerizations of rhodopsin. Due to incomplete characterization of rod noise and uncertainty in the behavioral measurements, this conclusion remains uncertain. To determine more exactly how noise in rod photoreceptors limits visual processing near threshold, we are characterizing the detection sensitivity and temporal resolution of primate retinal ganglion cells in response to dim flashes. We are comparing the performance of each ganglion cell class to the limits imposed by noise in rod photoreceptors. It this way we hope to determine whether rod noise or suboptimal retinal processing limits the sensitivity of the retinal output in primate. This project is in collaboration with Greg Field and Fred Rieke at the University of Washington (Seattle).

Publications & Abstracts

Uzzell, V.J., Rieke, F. and Chichilnisky, E.J. (2001). Spike timing precision and visual signalling in primate retinal ganglion cells. Society for Neuroscience Abstracts 27: 397.4

Uzzell, V.J., Field, G.F., Rieke, F. and Chichilnisky, E.J. (2002). Pooling of rod inputs and limits to sensitivity in mammalian retinal ganglion cells. Society for Neuroscience Abstracts 28: 158.6