FIGURE 8.

Kv1.2 channel gating can be modified by dialysis of cytosolic constituents. (A and B) Representative ionic currents (left) recorded in the whole-cell (A) and perforated-patch (B) configuration. Traces represent the current obtained immediately after breaking into the cell (solid trace; time = 0) and that recorded from the same cell 30 s, 60 s, and 90 s (in A) or 30 min (in B) later (shaded traces). Time dependence of the gating mode was seen in 3 of 10 cells in the whole-cell configuration but not in the perforated-patch configuration (right bar graphs). (C) Representative activating ionic currents (left) recorded from a cell-attached patch (solid trace) and after excision of the inside-out patch (shaded trace). An immediate switch from the “slow” to the “fast” gating mode was observed in eight of eight patches, which was complete 5 min after excision from the cell cytoplasm. In all cases ionic currents were recorded during depolarizing voltage steps to +40 mV at 30-s intervals from a holding potential of −80 mV.