The dependence of trout's electroretinographic response on temporal gradient of luminance. II. The off-response

In this study trout's electroretinographic off-responses, elicited by ramp-like off-stimuli of variable decay time were recorded and evaluated. In the off-response of the trout, at least two different subwaves could be separated. As the stimulus decay time was increased stepwise from 10 ms to 3000 ms, the earlier wave d1 showed a pronounced amplitude attenuation and only little increase of the peak time, while at the second, later wave d2 a less marked effect on the amplitude but a distinct increase of the peak time could be observed. Possible relations of the subwaves d1 and d2 to the photopic or the scotopic system, comparison with the on-response at similar stimulating conditions, and correlations with psychophysical findings are discussed. The parallels to the observations on mammals' ERG including the human being are demonstrated.