NOS1 and major depressive disorder: Impaired hippocampal neurogenesis contributed to chronic stress and elevated glucocorticoids‐induced depression and anxiety behavior.27, 28 Moreover, nNOS knockout and 7‐NI significantly enhanced hippocampal neurogenesis.28 Therefore, the 5‐HT1A receptor reactivation‐induced enhancement of hippocampal neurogenesis might contribute to the anxiety behavior rescue after a single infusion of 7‐NI.