Abstract
Abstract: :
Purpose: (1) Develop apparatus and establish experimental protocols for high throughput quantitative electroretinographic testing of mouse visual function; (2) Establish normative values of ERG parameters for the C576Bl/6 mouse; (3) Study the effect of ambient light on retinal function in the mouse. Methods: We have built a setup with 4 independent flash and 2 continuous light units controlled by a computer. This apparatus can generate any preprogrammed sequence of narrowband (10 nm ) and broadband flash and steady light stimuli in 340 – 700 nm range with interstimulus intervals from10 milliseconds to infinity. A suite of specialized Matlab utilities was developed to allow for processing large amounts of data. Animals were born and raised in light proof containers on 12/12 cycle at 2-3 ("dim") or 100-150 lux ("bright", typical of human workplace and animal facility illuminance) and were tested at 4, 6, 8 and 26 weeks. Results: We have determined the following parameters characterizing the mouse visual function: saturating amplitudes of the rod and cone b-waves and rod a-wave, rod phototransduction cascade amplification, sensitivity of the rod b-wave, sensitivity of the cone b-wave in UV and visible region (360 and 510 nm respectively). All these parameters grew in magnitude between 4 and 6 weeks, stayed stable between 6 and 8 weeks, and declined at 26 weeks. Conclusions: The visual function in C57Bl/6 mice matures between 4 and 6 weeks and declines after 8 weeks. "Bright"-reared animals had moderately decreased amplitudes and sensitivities of all ERG components relatively to "dim"-reared mice. Thus, intensities common for humans ambient lighting may cause mild reduction of retinal function in C57Bl6 mice.
Keywords: electroretinography: non-clinical • retina • animal model