Electroretinographic characterization of pigmented P23H transgenic rats

The homozygous parent strain of the P23H transgenic rat (developed as an animal model or retinal degeneration associated with human eye disease) was crossed with pigmented wild-type (Long Evans) rats. The pigmented offspring, heterozygous for the mutation in the rhodopsin gene, more closely resemble the human disease state. Single and paired-flash electroretinography was used to evaluate the retinal response to brief light flashes. A-wave amplitudes and sensitivity decreased with age up to 12 wks (the oldest rats currently in the colony); b-wave amplitudes and sensitivity were relatively preserved up to 12 wks. At 4 wks of age, the transgenic rats showed an earlier time to peak of the paired-flash-derived photoreceptor response, and a faster initial recovery from peak, when compared to age-matched wild-type.