ERG responses to maximum flash intensity of 3.5 log cd · s/m2 for mice treated with 11-cis retinal by intraperitoneal injection. (A) Rpe65−/− and (B) Rpe65−/−/Nrl−/− mice housed in complete darkness received injections of 11-cis retinal as follows: postnatal day (PN)10 and PN14, 1.25 μg; PN17, 2.5 μg; PN21, 3.75 μg; PN27 and PN33, 5.0 μg. ERG analysis was performed 24 hours after the final injection. (∎) 11-cis retinal injected (n = 4 Rpe65−/−, n = 2 Rpe65−/−/Nrl−/−); (▨) vehicle injected (n = 3 Rpe65−/−, n = 3 Rpe65−/−/Nrl−/−). Error bars, mean ± SEM.