The open field test is generally used to assess state and trait depressive-like behaviors [35] and both CUMS-exposed rats and MKP-1-overexpressing rats demonstrated relatively reduced activity in the center of the field, a hallmark of decreased interest and adaptability of rodents to new environments in this test, while MKP-1 knockdown in the hippocampus mitigated this and other behavioral signs of elevated depression. The gene discussed is DUSP1; the disease is depressive disorder.