Intrinsically Photosensitive Retinal Ganglion Cells Modulate Visually-Induced Innate Defensive Response

we performed looming visual stimulation experiments in two photoreceptor mutant models, Opn4-/- and rd1-/-/cDTA mice（melanopsin-only ：MO）, and compared the experimental results with wild type (WT) C57BL/6J mice. The results showed that in the perception of threat visual information, MO mice almost completely lost the instinctive defense response which induced by looming visual stimulation; However, the instinctive defense response of Opn4-/- mice to looming-evoked visual stimulation was significantly weakened. The results indicated that ipRGCs played a modulating role in visually-induced fear defense behavior.