Fig. 5: Pupil-induced binocular modulation facilitates low contrast responses.
From: Pupil size modulation drives retinal activity in mice and shapes human perception
A Predicted pupil-induced response in RGCs to contralateral stimulation (Left) and both screen stimulation (Right), showing increased pupil constriction (compare double red arrow in Contra to Both conditions), inducing predicted pupil-induced monocular response (Left, reaching dotted red line) and predicted binocular facilitation (Right, arrow) in OFF RGC responses. B Example RGC bouton response to low (left) or high (right) contrast stimulation from the contralateral screen (Top, purple) or both screens (Bottom, yellow). Traces are mean ± SD. Arrow = Pupil-induced binocular facilitation (as predicted in (A)), Arrowhead = Canonical OFF response. Throughout figure, purple is contralateral eye stimulation, yellow is both eye stimulation. C Heatmap (Top) of RGC difference between binocular and monocular responses (z-score), as well as population z-score average (Bottom trace) (n = 287 (low contrast, orange), 519 (high contrast, green) boutons, N = 5 animals). D Pupil response to contralateral (purple) or both eye (yellow) stimulation (top) compared to population average of RGC activity (bottom). Arrow = predicted binocular facilitation. (n = 287 (low contrast), 519 (high contrast) boutons, N = 5 animals). Traces are mean ± SEM. E Same as in (D), but after atropine administration to the contralateral eye, eliminating binocular facilitation (arrow). (n = 218 (low contrast), 776 (high contrast) boutons, N = 4 animals). Traces are mean ± SEM. F Same as in (D), but after carbachol administration, eliminating binocular facilitation (arrow). (n = 133 (low contrast), 307 (high contrast) boutons, N = 3 animals). Traces are mean ± SEM. G Spearman correlation between increased pupil contraction and binocular facilitation before (orange, green) and after (gray) atropine for low (Left, orange) and high (Right, green) contrast, with RGC activity to low contrast being substantially correlated to pupil activity. ***p < 0.001, *p = 0.0106 (two-sample two-sided k-s test). H Plot of RGC activity during stimulation onset to both eye stimulation (y-axis) against the sum of responses to the individual screens (x-axis) for low contrast (Left, orange) and high contrast (Right, green) (n = 287 (low contrast), 519 (high contrast) boutons, N = 5 animals). Low contrast = 9.5 Lux baseline to 20 Lux, high contrast = 9.5 Lux to 65 Lux.
