Fig. 2.
Dye transfer modulation by ionophoretic effect of Vj in the absence of Vj-gating. (A) Fluorescence image of a HeLaCx43-EGFP cell pair exhibiting a single JP (see Inset). (B) Simultaneous electrophysiological and fluorescence imaging recordings in the cell pair shown in A. The Vj trace shows the voltage protocol applied to cell-1 loaded with AF350 (see diagram in A). Repeated Vj ramps of ± 15 mV applied in cell-1 were used to measure Ij in between Vj steps of ± 20 mV (see expanded traces in the Top-Right Inset). FI1 and FI2 traces show dynamics of dye fluorescence in cell-1 and cell-2, respectively. Jγ,norm and Pγ traces show single channel flux normalized to the control value, and single channel permeability, respectively. On average, at Vj≈0 mV, Pγ = ≈83 ± 5 × 10−15 cm3/s (gray line). Two consecutive applications of CO2 (horizontal bars) were used to block GJs and calculate averaged Pp (Pp = 1.3 × 10−11 cm3/s).