Fig. 5: Block of GABAC receptors weakens radial direction selectivity in two On bipolar cell clusters.
From: Center-surround interactions underlie bipolar cell motion sensitivity in the mouse retina
a Top: iGluSnFR imaging. Middle: Moving bar stimulus and “1D noise” stimulus to measure radial direction selectivity (rDS) and assign cluster membership and predict motion responses. Bottom: drug treatment, see Methods for details. b Top: average RF of each cluster in control and in TPMPA. Arrow indicates the cluster whose average motion responses are shown in (f). Bottom: temporal RFs averaged from center (“c”) and surround (“s”) regions indicated above, normalized to their respective peaks. Temporal RFs in TPMPA (red) are normalized to the responses in control condition (black). Sample size is 3544 ROIs/ 3 fields/ 3 mice. c Full width half maximum (FWHM) of the spatial RF in control and TPMPA. d Top: linear convolution model predictions for originating (“O”) and terminating (“T”) motion using RFs from control or TPMPA conditions. Velocity, 1000 μm/s. Bottom: velocity tuning from these model predictions in control and TPMPA. e rDS of each cluster's modeled responses (at 1000 μm/s) as a function of cluster surround strength. Black dots: control, red dots: TPMPA, dotted lines connect the individual clusters. f Left: example response to moving bars (Gaussian Process prediction as in Fig. 1) for a ROI in the cluster indicated with an arrow in (b) in control and TPMPA conditions. Colors, estimated mean; gray shading, 3 s.d. Right: individual ROIs' responses (gray) and the cluster average. This was one of two clusters that showed a significant change in the rDS after applying TPMPA (see g). g rDS (d') for the ROIs in each cluster in control (gray) and TPMPA (red). Points, the mean; error bars, 95% confidence interval. Two-way ANOVA with repeated measures, significant for the effect of TPMPA (p = 5.87e − 11), but not cluster (p = 1) or interaction (p = 1). Post-hoc t-test with Bonferroni correction, significant for clusters marked with * (from left to right, p = 0.1387, 0.2398, 0.0017, 6e − 10, 0.1329, 0.9587, 0.4649). Data from 1464 ROIs/ 3 fields/ 3 mice. See also Supplementary Fig. 8.
