The postnatal development of the oscillatory potentials of the electroretinogram. I. Basic characteristics.

The postnatal development of the oscillatory potentials (OPs) of the rat electroretinogram (ERG) was studied. The appearance and/or completion of the development of the individual oscillatory peaks differed from that of the a- and b-waves as well as from each other. The OPs appeared postnatally one to two days later than the a- and b-waves, respectively. The first oscillatory peak, O1, was present before the second, O2, which appeared before the later wavelets, O3, O4 and O5. The pattern of maturation of the oscillatory peaks in relatively more scotopic conditions differed from that in relatively more photopic ones. The summed amplitudes of the OPs attained adult size earlier (about two weeks) during relatively more scotopic conditions. The peak time of each oscillation gradually decreased with age. These findings show that the origin of the OPs is different from that of the a- and b-waves of the ERG and strongly indicate different origins of the earlier OPs from the later ones. Thirdly, the scotopic mechanism underlying the OPs seems to mature faster than the photopic system involved in the generation of the OPs.