Rod- and cone-independent light responses of a WAC type that sparsely exhibits Crh-ires-cre-dependent fluorescence. A, Tracer coupling between an M2 ipRGC and a putative CRH+ AC. Confocal micrographs of Neurobiotin labeling in an injected M2 ipRGC and tracer-coupled somas (Nb, magenta, A1), ChR2-EYFP expression driven by a Crh-ires-cre allele (Crh-cre>ChR2-EYFP, green, A2), and their overlap (A3) in an Opn4-gfp+;Crh-cre+/−;Ai32+/− retina. *Soma of the injected M2 ipRGC. Arrowhead indicates single Neurobiotin-filled soma exhibiting Cre-dependent fluorescence. B, Circuit diagram illustrating electrical coupling between an ipRGC (left, blue) and a ChR2+ WAC (right, green). C, Rod- and cone-independent voltage response of a spiking ChR2+ WAC to a 1 s light pulse in a Crh-cre+/−;Ai32+/− retina (Φstim = 1.5 × 1016 Q cm−2 s−1).