BACKGROUND: The current study explored the underlying behavioral, endocrine, and immune markers of vulnerability to stress-induced depression, and the impact of rearing environments on adult functioning. METHOD: Adult Sprague-Dawley rats (n=195) were reared in either Maternal Separation (MS), Early Weaning and Isolation (EWI), or Non-Handled (NH) conditions. Anxiety behavior was assessed using the emergence test at mean postnatal day (PND) 60. Stress-induced depressive behavior was measured at mean PND 86 using an intermittent cold water swim stress and swim escape test (SET) paradigm. Immediately following the SET, and in a sample of naïve controls (N=31), trunk blood was collected to assay for serum corticosterone (CORT) and spleens were removed for determination of Concanavalin A (Con-A) stimulated T-cell proliferation. RESULTS: Stress vulnerable rats (top tertile of SET swim time) were characterised by increased anxiety-like behavior, greater post-stress CORT concentrations, and a significantly higher Con-A induced T-cell proliferative response compared to stress resilient rats (bottom tertile of SET swim time). The EWI rearing condition was a contributing factor in predicting total swim escape time, however MS was not. MS offspring did have double the basal level of CORT than NH offspring, suggestive of a hyperfunctioning HPA axis. CONCLUSION: The swim stress animal model enabled observation of stress vulnerability and resilience; results point towards the existence of distinct behavioral, endocrine, and immunological profiles of the vulnerable and resilient animal, which may have important implications for mental health and stress research.
BACKGROUND: The current study explored the underlying behavioral, endocrine, and immune markers of vulnerability to stress-induced depression, and the impact of rearing environments on adult functioning. METHOD: Adult Sprague-Dawley rats (n=195) were reared in either Maternal Separation (MS), Early Weaning and Isolation (EWI), or Non-Handled (NH) conditions. Anxiety behavior was assessed using the emergence test at mean postnatal day (PND) 60. Stress-induced depressive behavior was measured at mean PND 86 using an intermittent cold water swim stress and swim escape test (SET) paradigm. Immediately following the SET, and in a sample of naïve controls (N=31), trunk blood was collected to assay for serum corticosterone (CORT) and spleens were removed for determination of Concanavalin A (Con-A) stimulated T-cell proliferation. RESULTS: Stress vulnerable rats (top tertile of SET swim time) were characterised by increased anxiety-like behavior, greater post-stress CORT concentrations, and a significantly higher Con-A induced T-cell proliferative response compared to stress resilient rats (bottom tertile of SET swim time). The EWI rearing condition was a contributing factor in predicting total swim escape time, however MS was not. MS offspring did have double the basal level of CORT than NH offspring, suggestive of a hyperfunctioning HPA axis. CONCLUSION: The swim stress animal model enabled observation of stress vulnerability and resilience; results point towards the existence of distinct behavioral, endocrine, and immunological profiles of the vulnerable and resilient animal, which may have important implications for mental health and stress research.
Authors: Nadine Provençal; Matthew J Suderman; Claire Guillemin; Renaud Massart; Angela Ruggiero; Dongsha Wang; Allyson J Bennett; Peter J Pierre; David P Friedman; Sylvana M Côté; Michael Hallett; Richard E Tremblay; Stephen J Suomi; Moshe Szyf Journal: J Neurosci Date: 2012-10-31 Impact factor: 6.167
Authors: Lei Cao-Lei; Renaud Massart; Matthew J Suderman; Ziv Machnes; Guillaume Elgbeili; David P Laplante; Moshe Szyf; Suzanne King Journal: PLoS One Date: 2014-09-19 Impact factor: 3.240
Authors: Marith Van Schrojenstein Lantman; Marlou Mackus; Leila S Otten; Deborah de Kruijff; Aurora Jae van de Loo; Aletta D Kraneveld; Johan Garssen; Joris C Verster Journal: J Multidiscip Healthc Date: 2017-03-21
Authors: Chantal M Sanchez; David J Titus; Nicole M Wilson; Julie E Freund; Coleen M Atkins Journal: J Neurotrauma Date: 2020-09-16 Impact factor: 5.269