Figure 1.

Inhibitory effects of perampanel (PER) on the peak and late components of voltage-gated Na+ current (INa) in mouse hippocampal mHippoE-14 cells. In these experiments, we immersed the cells in Ca²⁺-free Tyrode’s solution containing 10 mM tetraethylammonium chloride (TEA) and the recording pipette was filled with a Cs+-containing solution. Once the whole-cell mode had been firmly established, the voltage protocol from −80 mV to different voltages with a duration of 80 msec was applied at a rate of 0.5 Hz. (A) Superimposed INa traces obtained in the controls (a) and presence (b) of 3 μM PER. The uppermost part shows the voltage protocol used. The lower part depicts an expanded record of late INa (INa,L) as indicated in the dashed box. (B) Concentration-response relationships for PER-induced suppression of INa measured at the beginning (□) and end (■) of the depolarizing pulses (mean ± SEM; n = 13 for each point). Smooth lines represent the least-squares fit to a modified Hill function as described in the Materials and Methods.