title: Behavioral and neurobiological characteristics influencing social hierarchy formation in female cynomolgus monkeys.
abstract: Socially housed monkeys have been used as a model to study human diseases. The present study examined behavioral, physiological and neurochemical measures as predictors of social rank in 16 experimentally naïve, individually housed female cynomolgus monkeys (Macaca fascicularis). The two behavioral measures examined were novel object reactivity (NOR), as determined by latency to touch an opaque acrylic box placed in the home cage, and locomotor activity assessed in a novel open-field apparatus. Serum cortisol concentrations were evaluated three times per week for four consecutive weeks, and stress reactivity was assessed on one occasion by evaluating the cortisol response to adrenocorticotropic hormone (ACTH) following dexamethasone suppression. Measures of serotonin (5-HT) function included whole blood 5-HT (WBS) concentrations, cerebrospinal fluid (CSF) concentrations of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) and brain 5-HT transporter (SERT) availability obtained using positron emission tomography (PET). After baseline measures were obtained, monkeys were assigned to four social groups of four monkeys per group. The two measures that correlated with eventual social rank were CSF 5-HIAA concentrations, which were significantly higher in the animals who eventually became subordinate, and latency to touch the novel object, which was significantly lower in eventual subordinate monkeys. Measures of 5-HT function did not change as a consequence of social rank. These data suggest that levels of central 5-HIAA and measures of novel object reactivity may be trait markers that influence eventual social rank in female macaques.
authors.affiliation: Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1083, USA.
authors.forename: N V
authors.initials: NV
authors.lastname: Riddick
authors.forename: P W
authors.initials: PW
authors.lastname: Czoty
authors.forename: H D
authors.initials: HD
authors.lastname: Gage
authors.forename: J R
authors.initials: JR
authors.lastname: Kaplan
authors.forename: S H
authors.initials: SH
authors.lastname: Nader
authors.forename: M
authors.initials: M
authors.lastname: Icenhower
authors.forename: P J
authors.initials: PJ
authors.lastname: Pierre
authors.forename: A
authors.initials: A
authors.lastname: Bennett
authors.forename: P K
authors.initials: PK
authors.lastname: Garg
authors.forename: S
authors.initials: S
authors.lastname: Garg
authors.forename: M A
authors.initials: MA
authors.lastname: Nader
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D001596:Benzylamines / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D002247:Carbon Isotopes / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D004291:Dominance-Subordination; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology; D006854:Hydrocortisone / Q000097:blood; D006897:Hydroxyindoleacetic Acid / Q000134:cerebrospinal fluid; D008252:Macaca fascicularis / Q000378:metabolism / Q000502:physiology* / Q000523:psychology*; D009043:Motor Activity / Q000502:physiology; D049268:Positron-Emission Tomography / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D012701:Serotonin / Q000097:blood; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism; D013997:Time Factors
chemical_list: D001596:Benzylamines; D002247:Carbon Isotopes; D005938:Glucocorticoids; C420885:N,N-dimethyl-2-(2-amino-4-cyanophenylthio)benzylamine; D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone