title: Stress coping style predicts aggression and social dominance in rainbow trout.
abstract: Social stress is frequently used as a model for studying the neuroendocrine mechanisms underlying stress-induced behavioral inhibition, depression, and fear conditioning. It has previously been shown that social subordination may result in increased glucocorticoid release and changes in brain signaling systems. However, it is still an open question which neuroendocrine and behavioral differences are causes, and which are consequences of social status. Using juvenile rainbow trout of similar size and with no apparent differences in social history, we demonstrate that the ability to win fights for social dominance can be predicted from the duration of a behavioral response to stress, in this case appetite inhibition after transfer to a new environment. Moreover, stress responsiveness in terms of confinement-induced changes in plasma cortisol was negatively correlated to aggressive behavior. Fish that exhibited lower cortisol responses to a standardized confinement test were markedly more aggressive when being placed in a dominant social position later in the study. These findings support the view that distinct behavioral-physiological stress coping styles are present in teleost fish, and these coping characteristics influence both social rank and levels of aggression.
authors.affiliation: Biology Department and Neuroscience Group, University of South Dakota, Vermillion, SD 57069, USA. oyvind.overli@bio.uio.no
authors.forename: Øyvind
authors.initials: Ø
authors.lastname: Øverli
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Korzan
authors.forename: Erik
authors.initials: E
authors.lastname: Höglund
authors.forename: Svante
authors.initials: S
authors.lastname: Winberg
authors.forename: Herbert
authors.initials: H
authors.lastname: Bollig
authors.forename: Michael
authors.initials: M
authors.lastname: Watt
authors.forename: Gina L
authors.initials: GL
authors.lastname: Forster
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Barton
authors.forename: Elisabeth
authors.initials: E
authors.lastname: ØVerli
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Renner
authors.forename: Cliff H
authors.initials: CH
authors.lastname: Summers
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D000374:Aggression / Q000502:physiology*; D000818:Animals; D004291:Dominance-Subordination; D005260:Female; D006608:Hierarchy, Social; D006854:Hydrocortisone / Q000097:blood; D007206:Individuality; D008297:Male; D016555:Matched-Pair Analysis; D017686:Oncorhynchus mykiss / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology*
chemical_list: D006854:Hydrocortisone