Speed, spatial, and temporal tuning of rod and cone vision in mouse

Abstract

Rods and cones subserve mouse vision over a 100 million-fold range of light intensity (-6 to 2 log cdm-2). Rod pathways tune vision to the temporal frequency of stimuli (peak, .75 Hz) and cone pathways to their speed (peak, ∼12°/s). Both pathways tune vision to the spatial components of stimuli (0.064-0.128 cycles/°). The specific photoreceptor contributions were determined by two-alternative, forced-choice measures of contrast thresholds for optomotor responses of C57BL/6J mice with normal vision, Gnat2cpfl3 mice without functional cones, and Gnat1-/- mice without functional rods. Gnat2cpfl3 mice (threshold, -6.0 log cdm-2) cannot see rotating gratings above -2.0 log cdm-2 (photopic vision), and Gnat1-/- mice (threshold, -4.0 log cdm -2) are blind below -4.0 log cdm-2 (scotopic vision). Both genotypes can see in the transitional mesopic range (-4.0 to -2.0 log cdm -2). Mouse rod and cone sensitivities are similar to those of human. This parametric study characterizes the functional properties of the mouse visual system, revealing the rod and cone contributions to contrast sensitivity and to the temporal processing of visual stimuli. Copyright © 2008 Society for Neuroscience.