Abnormal S-potentials recorded from isolated fish retinae and their relation to retinal neurotransmission

Intracellular recordings from horizontal cells in isolated fish retinae sometimes reveal that the cells are hyperpolarized in darkness and that their responses to light stimulation are reduced or completely suppressed [11,15]. At cessation of stimulation, however, the cells respond with a transient surge of depolarization. Data relating to this phenomenon are presented and analyzed in terms of Trifonov's [17] model for neurotransmission between retinal photoreceptors and horizontal cells. Good quantitative prediction of the experimental data can be obtained by using the relation between concentration of neurotransmitter and postreceptoral voltage response found for the electroplax membrane of the torpedo eel [4].