Bernstein et al. [153] reported a reduced density of astrocytes expressing the disrupted-in-schizophrenia 1 (DISC1) gene in the dentate gyrus in patients with schizophrenia; such a change could result in the reduced synthesis of D-serine [153], a potent NMDAR co-agonist that has been implicated in the etiology and treatment of schizophrenia [154,155]. Here, DISC1 is linked to schizophrenia.