Comparison of effect of mood stabilizers on TREK-1 and TREK-2 current. (a) Effect of LiCl, gabapentin, valproate, and carbamazepine on TREK-1; (b) No effect of LiCl, gabapentin, valproate, and carbamazepine on TREK-2 activity; (c) Summary of effect of LiCl, gabapentin, valproate, and carbamazepine on TREK currents. Each bar is the mean ± SD of five experiments. Asterisk (*) indicates a significant difference against the control without application of drugs (p < 0.05); (d) Dose-dependent effect of LiCl and carbamazepine on TREK-1 channel. The activation of TREK-1 current by increasing concentrations of LiCl (0.001 to 1 mM) and carbamazepine (1 to 100 μM).