title: Individual differences in chronically defeated male mice: behavioral, endocrine, immune, and neurotrophic changes as markers of vulnerability to the effects of stress.
abstract: This study aimed to analyze different behavioral profiles in response to chronic social defeat using the sensorial contact model. We hypothesized that a passive profile, unlike an active one, would be associated with behavioral and physiological characteristics related to depression. Six-week-old OF1 male mice were subjected to defeat for 21 consecutive days. A combination of cluster and discriminant analyses of the behavior exhibited during confrontation on Day 21 established two behavioral profiles: active (n = 22) and passive (n = 34). Passive mice, with a high level of immobility and low non-social exploration, had higher plasma corticosterone concentrations than active mice after 21 days of defeat. Three days after the last defeat, passive mice had lower corticosterone levels than manipulated-control mice (n = 11). Higher levels of interleukin-6 and tumor necrosis factor-α (TNF-α) in the spleen and lower hippocampal brain-derived neurotrophic factor levels were observed in passive mice in comparison with those in active mice and the manipulated controls. The only differences observed in active mice in relation to the manipulated control were higher plasma corticosterone (Day 21) and TNF-α levels. The results show that different behavioral profiles in response to chronic defeat are associated with different physiological profiles, and that the passive profile presents physiological characteristics previously associated with depression.
authors: Department of Basic Psychological Processes and Their Development, Basque Country University, San Sebastián, Spain.
authors: Eneritz
authors: E
authors: Gómez-Lázaro
authors: Amaia
authors: A
authors: Arregi
authors: Garikoitz
authors: G
authors: Beitia
authors: Oscar
authors: O
authors: Vegas
authors: Arantza
authors: A
authors: Azpiroz
authors: Larraitz
authors: L
authors: Garmendia
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology; D001522:Behavior, Animal / Q000502:physiology*; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D049109:Cell Proliferation; D003345:Corticosterone / Q000097:blood*; D004291:Dominance-Subordination; D006624:Hippocampus / Q000502:physiology; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007206:Individuality; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D051379:Mice; D010913:Pituitary-Adrenal System / Q000502:physiology; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D013315:Stress, Psychological / Q000097:blood* / Q000276:immunology; D013550:Swimming; D013601:T-Lymphocytes / Q000166:cytology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D003345:Corticosterone