Figure 3.

Effect of lidocaine on Na_v1.8 Na⁺ channels heterologously expressed in Xenopus oocytes. Whole-cell Na⁺ current traces of oocytes expressing Na_v1.8 before (a) and after (b) superfusion with 300 μM of lidocaine. Also shown in (c) are the effects of lidocaine (300 μM) on the current–voltage relationship (I/V curves) in control conditions (open circles) and in the presence of the anesthetic (filled circles). Currents were elicited by depolarizing steps between −80 and +40 mV in 5 mV increments from a holding potential of −100 mV (see figure inset for protocol). Dashed lines are zero current. I/V curves were obtained by plotting the current amplitude versus the voltage for the currents shown in (a) and (b).