Figure 1.

SA of gA channels measured in three different inside-out patches isolated from PC-20 liposomes. The suction pulse waveform for each panel is shown in the bottom trace. (A) In this patch there was no channel activity 100 s before suction stimulation. Application of a 5-s suction step of 200 mmHg activated ≈8 gA channels currents (≈1.1 pA) of which six deactivated after removal of the suction. Application of a 160-mmHg step reactivated three channels. (B) A different patch that displayed a spontaneous channel activity of ≈0.3 s⁻¹ for the 100 s before stimulation with an average channel duration of ≈0.8 s (28 events). Stimulation with a suction step of 95 mmHg activated five channels. (C) In the third patch no channel activity was recorded in the 30 s before stimulation. A stair case increase in suction up to 125 mmHg activated four channel currents that deactivated within 10 s of removing the suction. In A and B the patch potential was 60 mV and in C it was 80 mV. In all cases the patch currents were recorded in symmetrical 200 mM KCl, 40 mM MgCl₂, 10 mM Hepes/KOH, pH 7.0.