Fig. 5

Distribution of Function across the IPL

(A) Histograms of terminal abundance across IPL depth (y axis) and position in the eye (set of histograms) for each functional group (cf. Figure 7), divided by on- and off-dominated responses as indicated. In addition, the distribution of all n = 6,565 scanned terminals independent of response quality is plotted to reveal the anatomical distribution of all BC terminals (top, light gray). Heatmaps to the right show the same data in a single image. Asterisk denotes the position of the strike zone. Dashed lines indicate the forward and outward visual horizon. Solid horizontal lines indicate the position of the lower ChAT band as an anatomical reference.

(B_1–4) On and off-collapsed histograms of the four response groups for four example regions (down, dorsal; outward horizon, nasal as indicated; strike zone, temporo-ventral; up, ventral) summarize the functional IPL layering across eye positions, with approximate anatomical layers indicated in the background shading. For clarity, achromatic and UV(B)-monochromatic histograms are x axis reversed.

(C) Color-coded response groups (top) plotted against eye position (x) and IPL depth (y) and merge (bottom). Throughout, colors indicate the functional groups: achromatic (gray and black); UV(B)-monochromatic (purple and violet); chromatic (yellow and beige); and color opponent (orange and brown).