Ro 25-6981 efficiently reduce NMDA receptor-mediated fEPSPs. (a) Sample traces of NMDA receptor-mediated fEPSPs taken at baseline (CNQX, timepoint 1 in panel (b)), after application of Ro 25-6981 (1 μM, timepoint 2 in panel (b)), and at the end of the experiment (i.e., after D-AP5, timepoint 3 in panel (b)). Note that, at baseline, slices were already incubated in Mg2+-free ACSF containing CNQX (10 μM) and gabazine (1 μM). (b) Time course of the experiment showing the relative fEPSP slope (in % baseline). Following baseline, Ro 25-6981 (1 μM) was added to the bath and allowed to incubate for 15 min. Then, D-AP5 (50 μM) was applied in order to block all NMDA receptor-mediated fEPSP. (c) Bar graph summarizing the relative fEPSP slopes (in % baseline) for three different timepoints (CNQX, Ro, and D-AP5). Asterisks indicate significant differences as indicated by the brackets.