To assess whether the alteration of GluN2B‐containing NMDAR trafficking was causally linked to the age‐related memory impairment, we used the cell‐permeable TAT‐GluN2B‐9c peptide, which decreases GluN2B‐containing NMDAR synaptic content by disrupting GluN2B/PSD95 interaction (Aarts et al., 2002; Gardoni et al., 2009), as confirmed here by PLA (Figure S2). Here, GRIN2B is linked to memory impairment.