(A) Polar plots displaying peak calcium responses in T4 and T5 axon terminals to static gratings of different orientations after application of the GABAAR antagonist picrotoxin (PTX). Error bars are ±SEM. Layer A: N= 4(33). Layer B: N = 4(35). Layer C: N = 4(39). Layer D: N = 4(34). (B,C) Peak calcium responses in T4 and T5 axon terminals to static dark bars of various widths, after application of PTX, comparing horizontally and vertically oriented bars. N = 4 (20) for lobula plate layer A. N = 4 (24) for layer B. N = 4 (24) for layer C. N = 4 (22) for layer D. (D,E) Quantification of the difference in response to horizontally and vertically oriented dark bars that were 7 to 15° wide (D) or light bars that were 5 to 10° wide (E) after application of PTX, using averaged peak responses of the same ROIs used in panels (B,C) or in Figure S5 B,C. ** p<0.01, N.S. = not significant p>0.05, two tailed Student’s t-test. See also Figure S5.