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Updated: Jul 3, 2026
Simultaneous Recording of Electroretinography and Visual Evoked Potentials in Anesthetized Rats
Published on: July 1, 2016
Comparison of visual function in pigmented and albino rats by electroretinography and visual evoked potentials
Peter Heiduschka1, Ulrich Schraermeyer
1Section for Experimental Vitreoretinal Surgery, University Eye Hospital, Schleichstr. 12/1, D-72076, Tübingen, Germany. p.heiduschka@uni-tuebingen.de
Purpose:
To check differences in visual function between Wistar (albino) and Long-Evans (pigmented) rats.
Methods:
The animals were born in our facilities and reared under identical light conditions avoiding bright light. Visual electrophysiology was performed at the ages of 1.5, 4, 7 and 10 months (electroretinography, ERG) and at 1.5 and 7 months (visual evoked potentials, VEP).
Results:
ERG measurements showed that: 1) The amplitudes of both scotopic and photopic b-waves were markedly larger in Long-Evans rats than in Wistar rats, and also the amplitudes of scotopic oscillatory potentials and photopic 30 Hz Flicker amplitudes, 2) scotopic a-wave amplitudes were larger in Wistar rats at low light intensities, whereas they were smaller in bright light, 3) both a-wave and b-wave latencies were shorter in Wistar rats, 4) the maximum response Rm(P3) was larger in Long-Evans rats, 5) the sensitivity parameter S was larger in Wistar rats, and 6) the post-receptoral response of cones was smaller in Wistar rats. In the VEP measurements, amplitudes of both photopic and scotopic visual evoked potentials of Long-Evans rats were only slightly larger than those of Wistar rats.
Conclusions:
ERG b-wave amplitudes are markedly decreased in Wistar rats, which requires further investigation. As the b/a and OP/a ratios were also decreased in Wistar rats, it can be suggested that post-receptoral processing, in particular, is impaired in albino animals.
