Figure 4.

Effects of flupirtine on GABA_A and glycine receptors in hippocampal neurons. Neurons were clamped at −70 mV and increasing concentrations of GABA or glycine were applied for 3 to 5 s in the presence of either solvent or 30 µM flupirtine. (A and C) Original traces evoked by 3 µM GABA and 300 µM glycine, respectively. (B and D) Concentration–response curves for currents induced by GABA (n = 5 to 11) and glycine (n = 5), respectively. Amplitudes evoked by different agonist concentrations in solvent or flupirtine were normalized to those evoked in solvent in the very same neuron by 30 µM GABA and 100 µM glycine, respectively. Values for statistical differences (F-test) between EC₅₀ values in the presence of either solvent or flupirtine are P < 0.001 for GABA and P > 0.8 for glycine.