Effects of NGEN and flupirtine on spontaneous action currents recorded from NSC-34 neuronal cells. In (A), current traces were obtained in the absence (a) and presence (b) of 10 μM NGEN. The lower part shown at (a) and (b) indicates an expanded record from dashed box. Notably, the traces showing downward deflections indicate action currents. (B) Summary of the data showing effects of NGEN, flupirtine (Flu), NGEN plus linopirdine (Lino) on the frequency of action currents in NSC-34 cells. Each point indicates the mean ± SEM (n = 7-10). *Significantly different from control.