Ab. Fulton et al., THE DEVELOPMENT OF THE ROD PHOTORESPONSE FROM DARK-ADAPTED RATS, Investigative ophthalmology & visual science, 36(6), 1995, pp. 1038-1045
Purpose. To study electroretinographic a- and b-wave responses of rats
at the ages during which rod outer segment length (ROS) and rhodopsin
content increase. Methods. Electroretinographic responses to brief, f
ull-field stimuli were recorded from dark-adapted young (ages 12 to 30
days) and adult rats. The amplitude of the a-wave and the amplitude a
nd implicit time of the b-wave were examined as a function of stimulus
intensity. Sensitivity (S), saturated amplitude (Rm(ps)), and delay (
t(d)) of the rod cell responses were calculated from the a-waves. Resu
lts. The developmental increase in saturated a-wave amplitude parallel
s, but lags behind, growth of outer segment length, whereas the satura
ted b-wave amplitude increases with about the same course as rhodopsin
content of the retina. The sensitivity, S, depends on rhodopsin conte
nt, and the developmental decrease in the flash energy required to pro
duce a half-maximum b-wave amplitude is inversely proportional to the
developmental increase in rhodopsin content. No significant age-depend
ent variation in t(d) can be detected. Conclusion. During development,
ROS length and rhodopsin content of the retina are significant determ
inants of a- and b-wave response parameters.