ERG'S during the disappearance and recovery of the b-Wave induced by respiratory interference

Abstract

ERC's obtained from animals having all rod retinas were analyzed as the b-wave decreased from that present in the normal ERG to where there was no longer airy b-wave. This condition was induced by interfering with the animal's respiration. Except for an increase in the a-wave amplitude and peak latency, the a-wave appeared unaffected by this treatment. The b-wave amplitude and peak latency decreased and increased, respectively, until the b-wave completely disappeared. The normal air supply was restorec before any suppression of the a-wave occurred. The ERG did not fully recover to that of the untreated rat. In comparing the ERG's it appears as though an early portion of the b-wave was present in the untreated rat ERG is absent in the ERG obtained after recovery. The results were interpreted in terms of a model that assumes that the b-wave is composed of a number of sub-waves. Each sub-wave can be the result of a different homogeneous population of retinal cells interacting with the light stimulus, or by a series of reactions occurring within the retina, leading to the generation of an electrical potential. The summation of the reactions of all the different populations of cells to the same stimulus results in the b-wave. It is proposed that those populations of cells producing sub-waves having the shortest latencies are the most sensitive to respiratory interference. These sub-waves are the first ones affected by respiratory interference and do not fully recover after the interference is removed. It is also proposed that the a-wave can be desfribed by a pair of exponential functions, one function describing a rapidly falling phase and the other a slow recovery phase.