Purchase this article with an account.
S.G. Rosolen, C. Chalier, F. Rigaudière, P. Lachapelle, J. Le Gargasson; Flicker ERG Evidence that Sprague Dawley and Brown Norway Rats Have Different Cone-mediated Responses . Invest. Ophthalmol. Vis. Sci. 2003;44(13):1903.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:Compare photopic and scotopic flicker electroretinograms (fERG) in albino and pigmented rats. Methods:Binocular, full field ERGs were recorded from fully anaesthetised albino Sprague Dawley (SD) and pigmented Brown Norway (BN) rats. The retinal responses were evoked to 4 different temporal frequencies (1.3, 6, 20 and 30 Hz) presented in photopic (after 0 and 10 minutes of light-adaptation) and in scotopic (after 0, 0.5, and 12 hours of dark-adaptation) conditions. Results: Although both strains showed a gradual decrease in b-wave amplitude with increasing frequency of stimulation, the gain in amplitude, resulting from the dark-adaptation process, was significantly higher in responses to low frequencies (1.3 Hz and 6 Hz) of stimulation compared to higher ones (20 Hz and 30 Hz)and significantly higher in albino compared to pigmented rats. In photopic conditions, both strains yielded a gradual decrease in ERG amplitudes with increasing frequency of stimulation. Although the amplitude of the albino rat ERG was significantly larger than that of the pigmented rat at the onset of the light adaptation process, comparing T0/T10 amplitude ratios did not yield a significant enhancement with light adaptation in albino rats while it did in pigmented rats and that irrespective of the temporal frequency used. Conclusions: Our results clearly indicate strain differences between SD and BN rats in their response to flickering stimulus and that irrespective of the state of retinal adaptation. Given that the flickering stimulus is normally used to isolate cone function, one wonders if the above would suggest a difference in cone physiology between SD and BN or point to a possible contribution of the pigmented RPE (melanin) to explain the above mentioned differences.
This PDF is available to Subscribers Only