Figure 1.

Prepulse-dependent slowing of WT hERG channel deactivation. (A) Typical current traces from WT channels recorded in response to the protocol shown in which the depolarizing test pulse (+60 mV) duration (Δt, in ms) was varied. (B) Superposition of normalized ionic deactivation tail current traces from (A), recorded at −110 mV after 50, 500, and 15,000 ms steps to +60 mV to highlight the change in deactivation. (C) Plot of mean τ-fast component of deactivating current (τ_f deactivation) as a function of increasing depolarization duration at +60, +40, and +20 mV. Data were fitted to a double exponential function (n = 6, 5, and 4, respectively).