Figure 14.

Junctional current (Ij) and Vj sensitivity monitored in Xenopus oocyte pairs expressing heterotypic tandem–Cx32 channels. With trains of 60 mV Vj pulses positive at tandem side, three Ij behaviors are observed: monophasic Ij increase (pulses #1–3); biphasic Ij time-course (pulses #4–9) and conventional Ij behavior (pulses #10–18). This suggests that repeated application of Vj pulses, positive at the tandem side, renders all of the available channels (from pulse #10 onwards) progressively operational. Indeed, the application of the conventional Vj protocol to either oocyte immediately after the trains of 60 mV pulses results in a behavior very similar to that of 32–32 channels (pulses #19–27). Adapted from Reference [135].