Negoias et al. (2010) and Marsden (2013) reported that exposure to CUMS resulted in atrophy of limbic brain regions included hippocampus and MOB with subsequent olfactory dysfunction. CUMS exposure, in this study, led to reduction in immune and gene expression of GFAP in MOB, the selective astrocyte marker. This finding was consistent with what has been reported by Li et al. (2013), who mentioned that atrophy of microglia contributes to pathogenesis of depression. The gene discussed is GFAP; the disease is depressive disorder.