Electroretinography (ERG) recording

Full-field ERGs were recorded simultaneously from both eyes. Animals were dark-adapted overnight (>12 h). Mice were weighed and anesthetized with intraperitoneal injections of a mixture of ketamine (60 mg/kg) and xylazine (9 mg/kg). Mydriasis was achieved with one drop of 0.5% tropicamide with 5% phenylephrine. Corneal anesthesia was performed with a single drop of 0.5% proparacaine hydrochloride ophthalmic solution (Akorn Inc. Illinois). A warm heating pad was used to maintain body temperature (37°C).

ERGs were recorded using HMS's ERG LAB system (OcuScience, Nevada). Stimulus flashes were presented in a Ganzfeld bowl. Stimulus intensities ranging from −1.5 to 1.0 log cd s/m² in 0.5-log units steps were used under dark-adapted conditions. Light stimuli were presented with a 1-min interval between successive stimuli.