Figure 6. Interconversion between intramembrane and transmembrane charge movements.

A, average curves of the charge at the internal transporter position (see text), from 5 oocytes analysed as in Fig. 5. ▵, difference between □ (no GABA) and ○ (10 μm GABA); ▴ are derived from eqn (5). B, average charge transfer rates from the same oocytes (⋄, r; ▵, ○: unidirectional rates). C, average I_tr at the indicated GABA concentrations; open symbols are experimental data, filled symbols represent the currents calculated from eqn (4) using the values from the corresponding symbols in A multiplied by the rate in B (▪ (C) =□(A) ×⋄ (B); ▴ (C) =▵ (A) ×⋄ (B)). D, GABA apparent affinity evaluated as the concentration giving rise to half I_tr at each potential.