et al., 2003). Administration of IL-1β itself decreases cell proliferation and differentiation of new neurons in the adult mouse dentate gyrus (Goshen et al., 2008; Koo & Duman, 2008). In vivo and in vitro studies suggest that progenitor cells in the SGZ have IL-1 receptors and that activation of these receptors decreases cell proliferation (Koo & Duman, 2008). Inactivation of IL-1 receptors via transgenic manipulations (Goshen et al., 2008) or pharmacological antagonists (Ben Menachem-Zidon et al., 2008) block stress-induced depressive-like behaviors and decreased cell proliferation in the dentate gyrus. These findings suggest IL-1 may underlie the stress-induced decrease in adult neurogenesis in the dentate gyrus but since available evidence suggests that not all stressors activate this pathway, the mechanism is unlikely to be universal.
