We hypothesized that: (1) aggression levels and severity over the course of enriched housing would be comparable among SE and EE male CD-1 mice; (2) EE would increase social behaviors and reduce behaviors that reflect anxiety (Hendershott et al., 2016; Aujnarain et al., 2018); and (3) EE would limit plasma corticosterone elevations as well as brain cytokine and BDNF changes following exposure to a mild social (social interaction test) and non-social (elevated-plus maze) stressor (Rodgers et al., 1999; Koya et al., 2005; Skurlova et al., 2011). This evidence concerns the gene BDNF and Anxiety.