Effect of stress and repeated mild traumatic brain injury (r-mTBI) on hypothalamic-pituitary-adrenal (HPA) axis markers at 3 months after the second repeated unpredictable stress (RUS). No changes in plasma levels of adrenocorticotropic hormone (ACTH; A), corticosterone (B), cortisol (C), noradrenaline (D), or neuropeptide Y (E) were detected at 3 months after the second RUS. Representative Western blot images for a number of HPA axis markers in the hypothalamus (F). Quantification of Western blot images for GR (G), FKBP51 (H), and CRH (I) levels in the hypothalamus at 3 months after the second RUS. Levels of FKBP5 and CRH were reduced in r-mTBI and stress+r-mTBI groups relative to the control and stress-only groups, respectively. Data were analyzed using a two-way analysis of variance followed by two-stage linear step-up procedure of Benjamini, Krieger, and Yekutieli to correct for multiple comparisons (n = 4–6). Statistically significant discoveries versus the control group are denoted by “*”, while statistically significant discoveries versus the stress-only group are denoted by “+”. Color image is available online.