FIGURE 8.

Single hemichannel currents. (A) Current recorded from a HeLaCx26/SpIH cell. Perfusion with the Ca²⁺-free KAsp external solution did not induce a SpIH current increase in four preparations (5.9 ± 1.7 and 6.2 ± 1.9 pA/pF, before and after perfusion, respectively; P = 0.886). The operation of single functioning Cx26 hemichannels was visible throughout the experiment. Insert: segment of current recording on expanded time and current scales shows the opening and closing of a Cx26 hemichannel with a unitary conductance of ~280 pS. The external bath contained 500 μM cAMP. (B) Hemichannel currents elicited by biphasic 50 mV pulses recorded from HeLa Cx26 cells in a Ca²⁺-free KAsp solution. The all point current histograms yielded a conductance of ~290 pS.