A–C, each plot shows time course of the effect of repeated applications of LY354740 (50 nm; grey bar represents duration of compound application) to a single slice under the following conditions. A, control; B, in the presence of the GABAA+B receptor antagonists bicuculline (50 μm) and CGP55845 (5 μm); C, under control conditions following washout of GABA receptor antagonists. D and E, mean data showing action of LY354740 on the fEPSP late phase. D, control conditions (n = 9; *P < 0.05); E, in the presence of GABA receptor antagonists (n = 5).