title: Peripheral administration of oxytocin increases social affiliation in the naked mole-rat (Heterocephalus glaber).
abstract: The neuropeptide oxytocin regulates a wide variety of social behaviors across diverse species. However, the types of behaviors that are influenced by this hormone are constrained by the species in question and the social organization that a particular species exhibits. Therefore, the present experiments investigated behaviors regulated by oxytocin in a eusocial mammalian species by using the naked mole-rat (Heterocephalus glaber). In Experiment 1, adult non-breeding mole-rats were given intraperitoneal injections of either oxytocin (1mg/kg or 10mg/kg) or saline on alternate days. Animals were then returned to their colony and behavior was recorded for minutes 15-30 post-injection. Both doses of oxytocin increased huddling behavior during this time period. In Experiment 2, animals received intraperitoneal injections of either oxytocin (1mg/kg), an oxytocin-receptor antagonist (0.1mg/kg), a cocktail of oxytocin and the antagonist, or saline across 4 testing days in a counterbalanced design. Animals were placed in either a 2-chamber arena with a familiar conspecific or in a small chamber with 1week old pups from their home colony and behaviors were recorded for minutes 15-30 post-injection. Oxytocin increased investigation of, and time spent in close proximity to, a familiar conspecific; these effects were blocked by the oxytocin antagonist. No effects were seen on pup-directed behavior. These data suggest that oxytocin is capable of modulating affiliative-like behavior in this eusocial species.
authors: University of Toronto Mississauga, Department of Psychology, 3359 Mississauga Road, Mississauga, Ontario L5L 1C6, Canada. Electronic address: Skyler.mooney@utoronto.ca.
authors: Skyler J
authors: SJ
authors: Mooney
authors: University of Toronto Mississauga, Department of Psychology, 3359 Mississauga Road, Mississauga, Ontario L5L 1C6, Canada.
authors: Natasha R
authors: NR
authors: Douglas
authors: University of Toronto Mississauga, Department of Psychology, 3359 Mississauga Road, Mississauga, Ontario L5L 1C6, Canada; University of Toronto, Department of Cell & Systems Biology, 25 Harbord Street, Toronto, Ontario M5S 3G5, Canada.
authors: Melissa M
authors: MM
authors: Holmes
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001892:Camphanes / Q000008:administration & dosage / Q000494:pharmacology*; D004291:Dominance-Subordination; D005260:Female; D008297:Male; D019577:Mole Rats / Q000502:physiology*; D010121:Oxytocin / Q000008:administration & dosage / Q000494:pharmacology*; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D018045:Receptors, Oxytocin / Q000037:antagonists & inhibitors*; D012919:Social Behavior
chemical_list: D001892:Camphanes; D010879:Piperazines; D018045:Receptors, Oxytocin; D010121:Oxytocin; C086206:L 368899
keywords: Eusociality; Heterocephalus glaber; Huddling; L-368,899®; Naked mole-rats; Oxytocin; Oxytocin antagonist; Social investigation; Social proximity