Figure 7. Voltage-dependent gating of single K_ATP channels.

Records of channel activity obtained by shifting the patch holding potential to ± 40 mV using pulse protocols shown in the insets of A and B. At these potentials, all single-channel currents were inward. The lowest traces show the ensemble average of 16 single-channel records. Note the two different calibration scales for single-channel (top) and ensemble (bottom) currents. The recording pipette contained 125 mM K⁺ without Ca²⁺. For ensemble averages, the horizontal dotted lines indicate a zero current.