Further studies of the chemical sensitivity of the oscillatory potentials of the electroretinogram (ERG). III. Some omega amino acids and ethanol.

The action of some omega amino acids and the influence of ethanol on the oscillatory potentials (OPs) of the ERG were tested. Low doses of beta-alanine, an inhibitory amino acid, selectively suppressed the amplitude of the OPs without affecting the a- and b-waves. The earlier OPs (O1 O2) appeared somewhat more sensitive to the drug than the later ones (O3-O5). Higher doses extinguished all the OPs but also affected the maximum amplitude of the a- and b-wave. There was no noticeable change of the threshold sensitivity of the a- and b-waves. Valine in corresponding concentrations did not affect the OPs. Taurine did not change the OPs in most experiments but in some experiments a concurrent decrease of the OPs, a- and b-waves occurred. Thus, these findings support the view that only inhibitory feed-back circuits initiated by the amacrines give rise to the OPs. Ethanol had a differential and selective effect on the OPs. The later OPs (O3-O5) were sensitive to ethanol. In conclusion, these results support the notion that the individual oscillatory peaks are likely to have different origins and that the later OPs may perhaps be related to the off-components in response to brief stimulus light.