Figure 9.
US acts in part downstream of the photoreceptor to bipolar cell synapse. a, Left, Raster plots and PSTHs for visual and US (20 W/cm2) responses in the control condition for an example cell. Middle, Raster plots and PSTHs after 30 min of 20 μm L-AP4 perfusion. Right, Raster plots and PSTHs after 60 min of washout. b, Left, Histogram of On suppression index for visual stimuli: n = 33 (−1, complete suppression of On response; 0, no effect; +1, an On response appears with drug that was not present during control). Right, Histogram of On suppression index for US stimuli; n = 63. The mean was not significantly different from zero (p = 0.85, t test). c, Left, Visual versus US suppression indices; n = 29 (different distributions: Wilcoxon Signed Rank, p = 1.2 × 10−7, two-tailed). Diagonal line indicates equal suppression. Right, On-Off index from visual control (+1, pure ON cell; −1, pure OFF cell) versus US suppression index. Black line indicates a linear fit.