Figure 3.

Exemplar traces and parameter fits shown for P/Q-type channels. (A, left) Voltage reinhibition protocol as shown in Fig. 1 with a test pulse voltage of −10 mV and exemplar traces collected at −100 mV. (A, right) Peak currents from traces shown on left were normalized and shown versus duration of interpulse to −100 mV. Fits were obtained by using the same equations as in Fig. 1 (τ = 6.3 ms). (B, left) Voltage facilitation protocol and exemplar traces shown for P/Q-type channels at 100 mV. (B, right) Peak currents were normalized and shown versus length of the prepulse. Fits were obtained using a single exponential (τ = 5.2 ms). (C, left) Step protocol and exemplar traces shown for P/Q-type channels at −10 mV. (C, right) Dual fits are shown using traces with and without a prepulse (τ(−10) = 17.9 ms, W(∞,−10) = 0.789). (D₁ and D₂) Time constants, τ(V), and the fraction of channels in willing mode, W(∞,V), collected are shown along with fits using same equations that were used in Fig. 2. (D₃ and D₄) Fits for on and off rates (k _on(V) and k _off(V)) determined are shown along with calculated k _on(V) and k _off(V). Dashed lines represent N-type channel fits.