Agmatinase, an inactivator of the putative endogenous antidepressant agmatine, is strongly upregulated in hippocampal interneurons of subjects with mood disorders

► Agmatine is an endogenous antidepressant. ► Agmatine-degrading enzyme agmatinase is found in hippocampal interneurons. ► Agmatinase expression is increased in mood disorder.