Figure 7.

Comparison of the effects of therapeutic flupirtine concentrations in hippocampal, DRG and dorsal horn neurons. (A) The concentration-dependence of the effects of flupirtine on GABA_A receptors was investigated in hippocampal (HC; n = 6), DRG (n = 6 to 8) and dorsal horn (n = 5 to 8) neurons clamped at −70 mV using GABA concentrations corresponding to the calculated EC₅ values to induce currents; these EC₅ values were 0.4, 3 and 1 µM for hippocampal (HC), DRG and dorsal horn (DH) neurons, respectively. * indicates a significant difference versus the corresponding result in DRG and dorsal horn neurons at P < 0.05. (B) Outward currents at −30 mV or currents induced by GABA at the above EC₅ concentrations were determined in hippocampal (n = 6), DRG (n = 6 to 8) and dorsal horn (n = 4 to 5) neurons in the presence of either solvent or 3 µM flupirtine. The graph shows normalized current amplitudes in the presence of flupirtine; *** indicates a significant difference between the effects on the two types of currents as determined by a Kruskal–Wallis ANOVA followed by Dunn's multiple comparison test.