Neuroinflammation is implicated in depression-like behaviors in various animal models of depression. Therefore, in this study, we examined the effects of intracerebroventricular (i.c.v.) injection of anti- and pro-inflammatory mediators on depression-like behaviors. First, we examined antidepressant effects of resolvin E1 (RvE1), a bioactive lipid mediator with anti-inflammatory effect, in an animal model of chronic pain. The tail suspension test revealed the antidepressant effect of i.c.v. administration of RvE1 in a mouse model of chronic pain-induced depression. Next, we examined the effect of oncostatin M (OSM), a member of the interleukin-6 family cytokines. I.c.v. administration of OSM increased immobility time in the tail suspension test using naïve mice, suggesting the depressive effect of OSM. The results of this study further support the involvement of neuroinflammation in depression-like behaviors.