title: The protective effects of social bonding on behavioral and pituitary-adrenal axis reactivity to chronic mild stress in prairie voles.
abstract: Positive social interactions may protect against stress. This study investigated the beneficial effects of pairing with a social partner on behaviors and neuroendocrine function in response to chronic mild stress (CMS) in 13 prairie vole pairs. Following 5 days of social bonding, male and female prairie voles were exposed to 10 days of CMS (mild, unpredictable stressors of varying durations, for instance, strobe light, white noise, and damp bedding), housed with either the social partner (paired group) or individually (isolated group). Active and passive behavioral responses to the forced swim test (FST) and tail-suspension test (TST), and plasma concentrations of adrenocorticotropic hormone (ACTH) and corticosterone, were measured in all prairie voles following the CMS period. Both female and male prairie voles housed with a social partner displayed lower durations of passive behavioral responses (immobility, a maladaptive behavioral response) in the FST (mean ± SEM; females: 17.3 ± 5.4 s; males: 9.3 ± 4.6 s) and TST (females: 56.8 ± 16.4 s; males: 40.2 ± 11.3 s), versus both sexes housed individually (females, FST: 98.6 ± 12.9 s; females, TST: 155.1 ± 19.3 s; males, FST: 92.4 ± 14.1 s; males, TST: 158.9 ± 22.0 s). Female (but not male) prairie voles displayed attenuated plasma stress hormones when housed with a male partner (ACTH: 945 ± 24.7 pg/ml; corticosterone: 624 ± 139.5 ng/ml), versus females housed individually (ACTH: 1100 ± 23.2 pg/ml; corticosterone: 1064 ± 121.7 ng/ml). These results may inform understanding of the benefits of social interactions on stress resilience. Lay Summary: Social stress can lead to depression. The study of social bonding and stress using an animal model will inform understanding of the protective effects of social bonds. This study showed that social bonding in a rodent model can protect against behavioral responses to stress, and may also be protective against the elevation of stress hormones. This study provides evidence that bonding and social support are valuable for protecting against stress in humans.
authors.affiliation: a Department of Psychology , Northern Illinois University , DeKalb , IL , USA.
authors.forename: Neal
authors.initials: N
authors.lastname: McNeal
authors.affiliation: b Department of Psychology , Bournemouth University , Poole , UK.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Appleton
authors.affiliation: c Departments of Psychological and Brain Sciences, Pharmacology , and Health and Human Physiology, The University of Iowa , Iowa City , IA , USA.
authors.forename: Alan Kim
authors.initials: AK
authors.lastname: Johnson
authors.affiliation: a Department of Psychology , Northern Illinois University , DeKalb , IL , USA.|d Department of Psychiatry and Brain-Body Center , University of Illinois at Chicago , Chicago , IL , USA.
authors.forename: Melissa-Ann L
authors.initials: ML
authors.lastname: Scotti
authors.affiliation: a Department of Psychology , Northern Illinois University , DeKalb , IL , USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Wardwell
authors.affiliation: a Department of Psychology , Northern Illinois University , DeKalb , IL , USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Murphy
authors.affiliation: a Department of Psychology , Northern Illinois University , DeKalb , IL , USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Bishop
authors.affiliation: a Department of Psychology , Northern Illinois University , DeKalb , IL , USA.
authors.forename: Alison
authors.initials: A
authors.lastname: Knecht
authors.affiliation: a Department of Psychology , Northern Illinois University , DeKalb , IL , USA.
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Grippo
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000818:Animals; D003411:Arvicolinae; D001522:Behavior, Animal / Q000502:physiology*; D003345:Corticosterone / Q000097:blood*; D003863:Depression / Q000503:physiopathology; D005260:Female; D008297:Male; D010913:Pituitary-Adrenal System / Q000503:physiopathology*; D012919:Social Behavior; D013315:Stress, Psychological / Q000503:physiopathology*; D013550:Swimming
chemical_list: D000324:Adrenocorticotropic Hormone; D003345:Corticosterone
keywords: Chronic mild stress; hypothalamic-pituitary-adrenal axis; prairie vole; sex difference; social buffering; social isolation