A, B, The Nts1 antagonist, SR48692, was bath applied 10 min before and washed out 10 min after NT superfusion. Antagonist concentrations were higher than those of the agonist in each experiment to ensure receptor occupancy by the antagonist. A, SR48692 100 nm blocked NT-induced potentiation at 10 nm (99.2 ± 1.3%, n = 5, p = 0.028 measured 12 min after NT application). B, SR48692 500 nm attenuated NT-induced reduction at 100 nm (89.7 ± 0.9%, n = 8, p < 0.001). Comparisons were conducted between minutes 16 and 22. C, D, Effect of NT on NMDA-mediated EPSCs in Nts1 knock-out mice. C, 10 nm (91.1 ± 2.2%, n = 7, p = 0.006 compared with the effect of NT 10 nm in wild-type). D, 100 nm (85.6 ± 2.4%, n = 4, p = 0.008 compared with the effect of NT 100 nm in wild-type). Analysis was conducted between minutes 16 and 22.