title: Chronic non-social stress affects depressive behaviors but not anxiety in mice.
abstract: The etiology of most psychiatric disorders is still incompletely understood. However, growing evidence suggests that stress is a potent environmental risk factor for depression and anxiety. In rodents, various stress paradigms have been developed, but psychosocial stress paradigms have received more attention than non-social stress paradigms because psychosocial stress is more prevalent in humans. Interestingly, some recent studies suggest that chronic psychosocial stress and social isolation affects mainly anxiety-related behaviors in mice. However, it is unclear whether chronic non-social stress induces both depression- and anxiety-related phenotypes or induces one specific phenotype in mice. In the present study, we examined the behavioral consequences of three chronic non-social stress paradigms: chronic predictable (restraint) stress (CPS), chronic unpredictable stress (CUS), and repeated corticosterone-HBC complex injection (RCI). Each of the three paradigms induced mild to severe depression/despair-like behaviors in mice and resulted in increased immobility in a tail suspension test. However, anxiety-related phenotypes, thigmotaxis and explorative behaviors, were not changed by the three paradigms. These results suggest that depression- and anxiety-related phenotypes can be dissociated in mouse stress models and that social and non-social stressors might affect brain circuits and behaviors differently.
authors: Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Korea. ; Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul 110-799, Korea.
authors: Sang Ho
authors: SH
authors: Yoon
authors: Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799, Korea.
authors: Byung-Hak
authors: BH
authors: Kim
authors: Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799, Korea.
authors: Sang-Kyu
authors: SK
authors: Ye
authors: Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Korea. ; Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul 110-799, Korea. ; Seoul National University Bundang Hospital, Seongnam 463-707, Korea.
authors: Myoung-Hwan
authors: MH
authors: Kim
keywords: Anxiety; Chronic non-social stress; Depression; Open field test; Tail suspension test