Figure 5. Potent T-type current recovery at physiological resting potentials.
(a–c) Fast TP stimulation (TP −30 mV) using HP of −100 mV to induce inhibition, switched to a HP of −70 mV to induce recovery (see protocol in (a)). The inhibition of Cav3.3 and Cav3.1 currents was measured using fast TP stimulation at a HP of −100 mV (b–c, left panels) whereas the recovery of the Cav3.3 and Cav3.1 currents was measured on a HP of −70 mV (b–c, right panels). (d) Quantification of the increase (recovery) in Cav3.3, Cav3.1 and Cav3.2 currents (at HP −70 mV) as a function of the TP stimulation frequency (n = 5–40 per bar). The normalized current corresponds to the ratio of the current obtained after 2 min without stimulation (blue trace) to the initial current (1 s, red trace) recorded at a HP −70 mV.
Figure 5—figure supplement 1. Modulation of the Cav3.2 Met1549Ile mutant channel at a high frequency of stimulation.
Similar to that described for Figure 5, the Cav3.2 current recovery was measured at a HP of −80 mV (a–b, right panels) after their inhibition by 1 Hz stimulation at a HP of −100 mV (a-b, left panels) for wild-type (WT) Cav3.2 channels (b) and for the Cav3.2 Met1549Ile channels (c). The average current decrease at HP −100 mV and the average current increase at HP −80 mV are shown in (c) as insets in the left and the right panels, respectively (n = 23–31).