FIGURE 6.

Effects of open channel blockers. (A, B) Concentration–response plots for peak current (A) and summary of the half‐maximal inhibitory concentration (IC₅₀) values (B) for the inhibition by memantine. (C, D) Concentration–response plots for peak current (C) and summary of the IC₅₀ values (D) for the inhibition by ketamine. (E, F) Concentration–response plots for peak current (E) and summary of the IC₅₀ values (F) for the inhibition by MK‐801. Currents were obtained at a holding potential of −100 mV. (G) Normalized whole‐cell current–voltage plots for wild‐type (WT) GluN1/2A receptors in the absence (filled circles) and presence (open circles) of extracellular Mg²⁺ ions (1 mmol·L⁻¹). Note the block of current at negative voltages in 1 mmol·L⁻¹ Mg²⁺. (H) Normalized whole‐cell current–voltage plots for GluN1(Y668H)/2A variant receptors in the absence (filled circles) and presence (open circles) of extracellular Mg²⁺ ions (1 mmol·L⁻¹). Note the impaired block at negative voltages in 1 mmol·L⁻¹ Mg²⁺ and the greater relative outward current compared to WT receptors. Currents were normalized to +15 mV. ***p < .001, ****p < .0001.