The relation of retinal sensitivity and rhodopsin in developing rat retina

The authors have studied the relations of rhodopsin and retinal sensitivity in developing albino rats, (1) in the dark-adapted state and (2) after exposure to light that bleaches greater than 90% of rhodopsin. Developmental increases in dark-adapted b-wave sensitivity and rhodopsin content were related directly as has been reported previously for rhodopsin and PIII sensitivity of other developing retinas. During dark-adaptation, infant rat log a-wave and log b-wave sensitivities and adults' log b-wave sensitivity were related linearly to the proportion of rhodopsin present. The authors suspect that the sensitivity-rhodopsin relations of infant rat retina are determined mainly by photoreceptor processes. Thus, the infant rat provides a model for investigation of mechanisms underlying both (1) the direct relation of sensitivity and rhodopsin and (2) the log sensitivity-rhodopsin relation.