Figure 3.

Comparison of pupillary constriction in TKO mice expressing the wt-ChR2 and three ChR2 mutants. (A) Representative images for vehicle-injected mice and mice expressing wt-ChR2, ChR2-L132C, ChR2-C/C, and ChR2-C/S in response to light stimulation. (B) Significant pupil constriction was observed only in ChR2-C/S viral vector–injected mice. Application of atropine completely blocked pupil constriction. Light intensity: 3 × 10¹⁵ photons/cm²s with blue LED illumination (470 nm). Data are expressed as the mean ± SD, n = 4–7 eyes. ***P < 0.001.