Synaptic NMDA receptor-mediated currents in anterior piriform cortex are reduced in the adult fragile X mouse

► Excitatory synaptic currents in piriform cortex were compared in Fmr1-KO and WT mice. ► At 3-18 months of age, NMDA/AMPA ratios were lower in Fmr1-KO than in WT mice. ► mEPSCs mediated by AMPA receptors were not different in Fmr1-KO and WT mice. ► At 24-28 months of age, NMDA/AMPA ratios were similar in Fmr1-KO and WT mice.