Figure 1. Converting the voltage of the H⁺-selective microelectrode (A) into a H⁺-profile (B).

A: The H⁺ voltage of the H⁺-selective microelectrode (which is the difference between the voltages of the ion-selective and reference barrels of the double barreled micropipette) consists of 840 data points obtained during 7 min of recording (2 Hz) when the electrode was continuously withdraw from the choroid to the vitreous. B: The final H⁺-profile that represents the calculated extracellular H⁺ concentration plotted against the normalized retinal depth consists of 22 data points, 20 for average [H⁺]_o in thin retinal sections (each accounting for 5% of total retinal depth), plus the average [H⁺] in the choroid and the vitreous just outside of the retina. The horizontal line marks the choroidal [H⁺]; the arrow shows the amplitude of the H⁺-profile.