FOS and Anxiety: Even though long-term social isolation in mice can lead to abnormalities such as more anxiety-like behavior, greater hyperactivity, impaired recognition memory and changes in social interactions (Valzelli, 1973; Koike et al., 2009; Voikar et al., 2005) our naïves’ social isolation alone likely cannot explain their pattern of behavioral and LC c-Fos-IR results.