Figure 2.

RGCs of the mGluR6 homozygous null retina have a long-latency ON response. Responses of RGCs were recorded from WT and mGluR6-null retinas using a multielectrode array. These responses were sorted into individual units representing spiking responses from individual RGCs. A, Example raster plots of spiking responses from WT RGCs to individual stimulus presentations and their resulting peristimulus time histograms (PSTHs) are shown. Short-latency, transient ON, sustained ON, ON–OFF, and OFF responses are all recorded by the array. B, Example raster plots and corresponding PSTHs for mGluR6-null neurons with prominent long-latency ON responses are shown. No transient or sustained ON responses with short latency were recorded in these retinas. For all retinal PSTHs, bin width is 10 ms. The light/dark bar below the histograms represents the light stimulus, which originated from a computer monitor and was projected onto the retinal surface. Frequency is in impulses (spikes) per second (imp/sec). C, A large percentage of RGCs from mGluR6-null retinas had a long-latency ON response and an OFF response. Values indicate the number of neurons recorded from 32 null retinas.