Abstract
The relation of the threshold of the late receptor potential (late RP) and ERG b-wave with the rhodopsin concentration in the rod outer segments of an isolated bullfrog retina were studied by simultaneous recordings of electrical responses and spectral change. The curve indicating log threshold rise of the late RP with the decrease of rhodopsin showed two phases separated by a kink, which was found at 50% rhodopsin concentration; the b-wave threshold, however, was linearly related to rhodopsin concentration. From the intensity response curves (IR curves) at various rhodopsin concentrations, the amplitude decrease of both waves following bleaching light adaptation was compared and the mode of the conversion from the late RP to the b-wave was discussed.
