DUSP1 and major depressive disorder: To this end, we compared depression-like behaviors and expression levels of microglial activation and neuroinflammatory markers among three animal models: (1) a rat model of depression induced by chronic unpredictable mild stress (CUMS), (2) rats overexpressing MKP-1 by adeno-associated virus (AAV) infection, and (3) CUMS-exposed rats underexpressing MKP-1 due to AAV-induced knockdown.