Fig. 7: ACh signals in DSGCs are locally, but not globally, tuned for direction.

a Two photon image of DSGC dendrites selectively labeled with ACh3.0, using the Oxtr-T2A-Cre mouse line (see Supplementary Fig. 7 for a more detailed characterization of this new mouse line). The colors indicate the preferred direction for each site (top), and its tuning strength (bottom), quantified from the responses to spots of light moving in 8 directions (See methods). Tuning strength was quantified from the direction selectivity index (DSI; See Eq. 4), where 0 indicates non-tuned, and 1 indicates responses only in the preferred direction. In total, 10 such field of views were imaged from 3 DSGCs. b Noise correlations (trial-to-trial fluctuations around the mean ACh3.0 signal) plotted over distance (λ, space constant; black). The spatial decay of ACh signals associated with single starburst stimulation measured in Fig. 6d is shown for comparison (red) (a.u., auxiliary units). c Example ACh ΔF signals evoked by spots moving in 8 different directions, measured in the two ROIs shown in a. Data represented as mean (black) ± SEM (gray) from 4 trials. d Relative frequency histogram of the preferred directions of all the ROIs in polar form (p = 0.81, n = 723 ROIS, 3 DSGCs; Hodges-Ajne non-parametric test for angular uniformity of the data) indicates a random distribution of angles with respect to the DSGCs preferred and null directions (PD and ND, respectively). e Relative frequency histogram of the DSIs of all the ROIs in control, and in the presence of an ACh esterase blocker (50 nM ambenonium). Source data are provided as a Source Data file for Fig. 7b, d, e.