*2.5. Visual Function Testing*

Full-field scotopic and photopic electroretinograms (ERGs) were obtained as described in detail previously using an OcuScience® HMsERG instrument (OcuScience, Henderson, NV, USA) [22]. Response amplitudes and implicit times of a-waves and b-waves representing the activity of photoreceptors and bipolar cells, respectively, were quantified. In brief, mice were dark-adapted overnight, anesthetized, and then placed on a heating pad to maintain body temperature. Following pupil dilation with 2.5% phenylephrine and 1% tropicamide ophthalmic solutions, a thin silver wire electrode was placed on the cornea (interfaced with methylcellulose and covered with a specially designed contact lens) and referenced to a needle ground electrode in the cheek. The responses to Ganzfeld flash stimuli, spanning a range of five log units, were measured and recorded; following light adaptation to background illumination, cone-driven responses also were recorded.
