Fast and Slow Components in the Electroretinogram of the Gastropod

The electroretinogram of the isolated eye of the gastropod (Haliotis discus) was studied with penetrating microelectrodes. The response recorded from the retinal surface with respect to the back of the eye was a slow negative potential change, but the response from the deeper layer was positive in polarity, indicating a depolarization of the distal part of the receptor cells. The electroretinogram of the dark adapted retina was a monophasic potential which had a smooth rising phase, but that of the light adapted retina was more complex in form, having an inflection which suggests the existence of the two responses in this simple retina of the abalone. Experiment of strong light adaptation and application of hypertonic KCl or ether vapor revealed that the electroretinogram consists of fast and slow components, and that the slow component is more susceptible to light adaptation and chemicals. Since one of the two responses originates undoubtedly from the receptor cells, the other origin was concluded to be the supporting cells, the response of which may be generated by some metabolic processes between the receptor and supporting cells.