Serotonin 1A agonism decreases affiliative behavior in pair-bonded titi monkeys

• Published in: Hormones and behavior Vol. 86; pp. 71 - 77
• Main Authors: Larke, Rebecca H., Maninger, Nicole, Ragen, Benjamin J, Mendoza, Sally P., Bales, Karen L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2016; Elsevier BV
• Subjects: 8-Hydroxy-2-(di-n-propylamino)tetralin - pharmacology; 8-OH-DPAT; Animal behavior; Animals; Behavior, Animal - drug effects; Callicebus; Cortisol; Female; Hydrocortisone - blood; Male; Males; Monkeys & apes; Monogamy; Oxytocin; Oxytocin - blood; Pair Bond; Pair-bonding; Pitheciidae - physiology; Pitheciidae - psychology; Primate; Receptor, Serotonin, 5-HT1A - metabolism; Serotonin; Serotonin - pharmacology; Serotonin 5-HT1 Receptor Agonists - pharmacology; Social Behavior; Vasopressin; Vasopressins - blood; Social behavior; Oxytocin; Monogamy; Primate; Cortisol; Pair-bonding; Vasopressin; 8-OH-DPAT
• ISSN: 0018-506X; 1095-6867; 1095-6867
• DOI: 10.1016/j.yhbeh.2016.10.001

Relatively little is known about serotonergic involvement in pair-bonding despite its putative role in regulating social behavior. Here we sought to determine if pharmacological elevation of serotonin 1A (5-HT1A) receptor activity would lead to changes in social behavior in pair-bonded male titi monkeys (Callicebus cupreus). Adult males in established heterosexual pairs were injected daily with the selective 5-HT1A agonist 8-OH-DPAT or saline for 15days using a within-subjects design. Social behavior with the female pair-mate was quantified, and plasma concentrations of oxytocin, vasopressin, and cortisol were measured. When treated with saline, subjects showed reduced plasma oxytocin concentrations, while 8-OH-DPAT treatment buffered this decrease. Treatment with 8-OH-DPAT also led to decreased plasma cortisol 15minutes post-injection and decreased social behavior directed toward the pair-mate including approaching, initiating contact, lipsmacking, and grooming. The reduction in affiliative behavior seen with increased activity at 5-HT1A receptors indicates a substantial role of serotonin activity in the expression of social behavior. In addition, results indicate that the effects of 5-HT1A agonism on social behavior in adulthood differ between rodents and primates. •Agonism of 5-HT1A receptors decreases adult social behavior in titi monkeys.•Serotonin activity plays an important role in social behavior within the pair-bond.•Effects of 5-HT1A agonism on social behavior differ between rodents and primates.