GRIN2A and major depressive disorder: To address this, we utilized MPX-004, a potent and selective negative allosteric modulator of GluN2A [46, 47], to investigate the effects of GluN2A antagonism in the dorsomedial prefrontal cortex (dmPFC), a brain region implicated in both depression [1–3,48] and schizophrenia [2, 8].