[Relationship between photoinduced changes in the intercellular concentration of potassium ions and transretinal potential generation by the Muller cells of the retina].

In isolated frog retina after treatment with aspartate the photoinduced change of the extracellular potassium ions concentration [K+]0) was compared with slow PIII potential (sPIII). The time course of [K+]0 change in the outer nuclear layer was like that in sPIII one. Both the size of [K+]0 change and the sPIII amplitude were increased almost in proportion to the Log light stimulus duration in the whole range of durations used (from 13 ms to 13 s). Such similarity between these two processes suggests that there is a direct relationship between sPIII and [K+]0 change. On the basis of our data the electrical model of sPIII generation by Muller cells in response to photoinduced [K+]0 change in the photoreceptor layer is proposed.