GAD1 and major depressive disorder: To assay changes in the expression of a GABA-synthesizing enzyme marker (GAD67) and an important neurodevelopmental protein marker (Reelin, a glycoprotein preferentially secreted by cortical GABAergic interneurons) (47)in our depression/anxiety-like mouse model, the expression levels of GABAergic genes in the cerebral cortex were assessed through ISH analysis at P77.