LTD was induced in hippocampal slices derived from either wild type C57BL6/J mice (WT control, solid line) or Fmr1 knockout mice (Fmr1 KO control, closed circles) with 100 μM DHPG for 5 min (n=12). Hippocampal slices derived from Fmr1 knockout mice were perfused with 120μM NSC23766 (Fmr1 KO + NSC, open squares; n=8). Inset shows fEPSP sample traces recorded during baseline (a, c) and 1hr after DHPG (b, d). Scale: 15mV, 5ms; p > 0.05, two-way ANOVA.