Fig. 6: The dynamics of pupillary constriction constrain PLR-driven RGC activity.
From: Pupil size modulation drives retinal activity in mice and shapes human perception
A Design of visual stimulus of increasing contrast that allows for the pupil to track each contrast change, by having the flashes presented at 0.55 Hz (left, blue), compared to stimulus of identical properties, but presented at 2 Hz (right, red). Horizontal arrows indicate flash length at each frequency. Throughout the figure, blue indicates 0.55 Hz stimulus, red 2 Hz stimulus. B Pupil size of contralateral eye due to contralateral (purple), ipsilateral (green), or both screen (yellow) stimulation at either 0.55 Hz (left) or 2 Hz (right). (N = 5 (0.55 Hz) and 3 (2 Hz) animals). Mean ± SEM. C, D Population RGC axon activity from 0.55 Hz (left) or 2 Hz (right) stimulation to either the contralateral (C, purple) or ipsilateral (D, green) eye. (n = 1381 (0.55 Hz), 648 (2 Hz) boutons, N = 9 (0.55 Hz), 5 (2 Hz) animals). E Increased pupillary constriction on both eyes compared to the contralateral eye for 0.55 or 2 Hz amplitude ramp. n.s. (two sample t test) (N = 5 (0.55 Hz) and N = 3 (2 Hz) animals, 6 repeats). White point = median. F Example RGC axon activity when presented with 0.55 Hz (left) or 2 Hz (right) amplitude ramp, with binocular facilitation (both eye responses (yellow trace) greater than contra eye responses (purple trace)) only observed at 0.55 Hz. Mean ± SD. G binocular facilitation (RMI) for top 50% OFF RGCs at each peak of the ramp at 2 Hz (top, red), 0.55 Hz (middle, blue), or 0.55 Hz after atropine administration (bottom, gray). Arrow = peak binocular facilitation. (n = 691 (0.55 Hz), 351 (0.55 Hz + atropine), n = 324 (2 Hz)). Color = peak number. Bars = Mean. H Population means for (G). bars = SEM. I, J Paired binocular facilitation in individual boutons at low contrast (peaks 2, 3, 4) or high contrast (peaks 9, 10, 11) in (I) anesthetized, top 50% boutons (n = 691 (0.55 Hz), 351 (0.55 Hz+atropine), 324 (2 Hz) boutons, N = 5 (0.55 Hz), 4(0.55 Hz+atropine), 3(2 Hz)) or (J) awake animals, all boutons. ***p < 0.001 (paired two-sided t test) (n = 213 (0.55 Hz), 312 (2 Hz) boutons, N = 4 animals). Line = mean. K Mean RMI difference at low contrast in (J). ***p < 0.001 (two-sample two-sided t-test). White point = median.
