Fig. 2. Optogenetic therapy restores characteristic retinal ganglion cell responses to patterned stimuli in the living primate.

a Pixelwise map of the temporal phase of ganglion cells responding to a 0.2 Hz drifting grating presented to foveal cones. b The spatial frequency of the ganglion cell layer (GCL) response to a 2.7 cycles per degree stimulus presented at the fovea. The spatial frequency of the response is lower than the spatial frequency of the stimulus because of the anatomical expansion of the ganglion cell density relative to the density of the foveal cones to which they are connected. c The spatial frequency of the ChrimsonR mediated ganglion cell response to a 2.7 cycles per degree stimulus applied directly to the ganglion cell ring matches the spatial frequency of the stimulus. d The spatial frequency of the ChrimsonR mediated GCL response to a 1.7 cycles per degree stimulus exactly matches the spatial frequency of the stimulus. This lower spatial frequency stimulus applied to the GCL mimics the natural photoreceptor mediated response to the higher spatial frequency shown in (b). e Applying a 1.1 cycles per degree stimulus directly to the GCL in the control animal, which did not receive ChrimsonR treatment, elicits no spatial response. All scale bars 100 μm. Depending on the available light budget, trials were repeated up to three times in the same location within a single imaging session and produced similar results.