Hyperpolarization of a single sustained OFF amacrine cell disinhibits local ganglion cells. A, Spiking responses from a transient OFF (left), sustained OFF (middle), and ON (right) ganglion cell after current injection into a sustained OFF amacrine cell. Top, Current stimulus (±0.5 nA). Middle, Raster graphs of spikes on 100 trials. Bottom, Average firing rate over trials. B, Disinhibition of ganglion cell firing plotted as a function of distance from the stimulated SOA. This is the fraction of the spikes of a ganglion cell that occurred during the 1 s hyperpolarizing current step in the experiment of A. “Silent” GCs did not fire during this procedure but were active during light stimulation. Based on recordings of eight SOAs and 87 GCs.