Figure 7.

ATX and lidocaine effects on Na currents of Purkinje neurons. Na currents in Purkinje neurons without (A, C) and with (B, D) ATX. A, B, Currents evoked by step depolarizations in control (black) and 100 μM lidocaine (gray). Each panel shows paired comparisons from a single cell. C, D, Activation and steady-state inactivation curves with mean values from Boltzmann fits of individual cells in control (thick black lines) and lidocaine (gray lines). Activation curve (E) and inactivation curve (F ) fit parameters without (black bars) and with (gray bars) ATX in control (left bar of each pair) and lidocaine (right bar of each pair). Control: −lidocaine, n = 4; +lidocaine, n = 5; ATX: −lidocaine, n = 4; +lidocaine, n = 5. G, H, Resurgent current in a Purkinje neuron evoked at −30 mV after a 15 ms step to +30 mV in control (G) and ATX (H ) without (black) and with (gray) lidocaine. I, J, Current-voltage relationships for maximal resurgent (circles) and steady-state (triangles) Na current in control (I ) and ATX (J ), without (black, n = 5) and with (gray, n = 5) lidocaine. K, Averaged resurgent currents, enlarged and scaled to compare kinetics without ATX (gray, n = 5) and with ATX (black, n = 5). L, Averaged resurgent currents from five Purkinje cells, enlarged and scaled to compare kinetics without lidocaine (gray, n = 5) and with lidocaine (black, n = 5). *p < 0.05. **p < 0.005.