Female dominance hierarchies influence responses to psychosocial stressors

• Published in: Current biology Vol. 33; no. 8; pp. 1535 - 1549.e5
• Main Authors: Smith-Osborne, Lydia, Duong, Anh, Resendez, Alexis, Palme, Rupert, Fadok, Jonathan P.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 24.04.2023
• Subjects: Animals; Anxiety; corticosterone; dominance hierarchy; elevated plus maze; Female; Hierarchy, Social; Male; Mice; open field test; paraventricular thalamus; Phenotype; psychosocial stress; rearing; Social Dominance; social instability; Social Isolation; social isolation; rearing; psychosocial stress; dominance hierarchy; elevated plus maze; paraventricular thalamus; female; open field test; corticosterone; social instability
• ISSN: 0960-9822; 1879-0445; 1879-0445
• DOI: 10.1016/j.cub.2023.03.020

Social species form dominance hierarchies to ensure survival and promote reproductive success. Traditionally studied in males, rodent hierarchies are considered despotic, and dominant social rank results from a history of winning agonistic encounters. By contrast, female hierarchies are thought to be less despotic, and rank is conferred by intrinsic traits. Both social buffering and elevated social status confer resilience to depression, anxiety, and other consequences of chronic stress. Here, we investigate whether female social hierarchies and individual traits related to social rank likewise influence stress resilience. We observe the formation of dyadic female hierarchies under varying conditions of ambient light and circadian phase and subject mice to two forms of chronic psychosocial stress: social isolation or social instability. We find that stable female hierarchies emerge rapidly in dyads. Individual behavioral and endocrinological traits are characteristic of rank, some of which are circadian phase dependent. Further, female social rank is predicted by behavior and stress status prior to social introduction. Other behavioral characteristics suggest that rank is motivation-based, indicating that female rank identity serves an evolutionarily relevant purpose. Rank is associated with alterations in behavior in response to social instability stress and prolonged social isolation, but the different forms of stress produce disparate rank responses in endocrine status. Histological examination of c-Fos protein expression identified brain regions that respond to social novelty or social reunion following chronic isolation in a rank-specific manner. Collectively, female rank is linked to neurobiology, and hierarchies exert context-specific influence upon stress outcomes. •Behavior and endocrinology can predict female rank in future social pairings•Female rank attributes are context dependent and influenced by circadian phase•Social status influences phenotypes arising from chronic psychosocial stressors•Rank informs neuronal activation patterns after chronic stress and social encounters Smith-Osborne et al. demonstrate that in female mouse dyads, there exists a motivation difference by rank that is stress-sensitive and engages various behavioral, endocrinological, and neurobiological responses to maintain homeostasis. The findings support the consideration of female social identity in rodent models of neurologic disease.