Figure 3.

Transient outward K⁺ currents induced by depolarization of the membrane potential measured in the whole-cell configuration of the patch-clamp technique. The depolarizing pulses started from a holding potential of −80 mV. The elicited currents in A–C correspond to membrane depolarizations to −80 mV, −40 mV, and −10 mV, respectively. (A) Whole-cell current measurement of a Kv1.4-transfected MDCK-F cell under control conditions. The Kv1.4 current was activated at −60 to −50 mV, and it decayed exponentially within 50 ms. (B) The same cell as in A in the presence of 10 mM 4-aminopyridine. (C) No Kv1.4-like current could be recorded in mock-transfected MDCK-F cells.