Figure 4.
PP2A-GSK-3β, but not Gq11, signaling pathway is involved in the high-dose DA/D2-induced depression of NMDA-EPSCs. A, Coapplication of GSK-3β inhibitors TDZD (10 μm) or SB216,763 (10 μm), the two structurally different GSK-3β inhibitors, completely abolished the DA-induced suppression in NMDA receptor mediated-EPSCs (n = 6; p < 0.01 for both). Both inhibitors themselves, however, did not show clear effects on the basal NMDA receptor-mediated transmissions (data not shown). B, Coapplication of Gq11 inhibitor (10 μm) with DA (100 or 200 μm), however, did not affect the effects of DA (n = 6; p > 0.05). C, D, PP2A inhibitor okadaic acid (100 nm) significantly blocked the DA effects on NMDA receptor-mediated EPSCs (n = 6; p < 0.05). Error bars indicate SEM.