GRIA2 and major depressive disorder: Besides gated ion channels, another striking observation in PFC is the selective enrichment of Gria1 (Fig. 4a), a principal ionotropic AMPA glutamate receptor subunit (forms dimer–dimer pair with GluA2), which is implicated in several neuropsychiatric disorders (such as schizophrenia, epilepsy and depression), chronic pain (increase), Alzheimer’s (decrease) and drug addiction (decrease)39,40.