Control of membrane N+ permeability in a hyperpolarizing photoreceptor: similar effect of light and metabolic inhibitors

In the hyperpolarizing photoreceptors of the scallop Pecten irradians the metabolic inhibitors cyani 'e and 2,4-dinitrophenol cause a rapid hyperpolarization and increase in membrane permeability to potassium ions, similar to the effect of light. Cellular metabolism appears important in maintaining the low permeability to potassium ions necessary to keep the membrane depolarized in darkness, possibly by regulating the intracellular calcium ion concentration.