Fig. 1.

PSD-95 expression partially occludes PKC potentiation of NMDA-elicited currents. NMDA-elicited currents (100 μM NMDA with 10 μM glycine) were recorded in Ca²⁺ Ringer's solution at a holding potential of −60 mV from oocytes expressing NR1–4b/NR2A receptors in the absence or presence of PSD-95. (A and B) PKC activated by TPA potentiated NMDA-elicited currents in oocytes expressing NR1/NR2A receptors (Left). Expression of PSD-95 increased the initial or basal NMDA-elicited currents by ≈2-fold, but PKC potentiated NMDA currents to similar final values in the presence and absence of PSD-95 (Right). (C) Quantitation of these data. (D) Because PSD-95 increased the basal response but not the response after TPA, the potentiation ratio was reduced from ≈10- to ≈5-fold. ∗∗, P < 0.01; ∗∗∗, P < 0.001. n.s., not significant.