The postnatal development of the oscillatory potentials of the electroretinogram V. Relation to the double peaked a-wave.

The postnatal development of the double peaked a-wave and its relation to the oscillatory potentials of the rat electroretinogram was studied. The split a-wave appeared one day later than the first oscillatory activity. The appearance and maturation of the positivity between the two a-waves (a-hump) was found to be similar to that of the first oscillatory potential, and the development of the second a-wave showed similarities to that of the second oscillatory potential. Thus, we conclude that the double peaked a-wave is closely related to the appearance of the two first oscillatory potential. Secondly, the division of the a-wave in the immature animal may be caused by the intrusion of the first oscillatory potential. Thirdly, the presence of a split a-wave before spontaneous opening of the lid seems to indicate a state of comparatively progressed maturity of neuronal adaptation.