Oxytocin effects on the behavior in historical and experimental domesticated animals

Abstract

Domestication is one of the important evolutionary and genetic problems of biology. It addresses fundamental evolution aspects as well as allows us to study mechanisms of aggression, pro-social behavior and anthropogenesis. One of the potential key mechanisms of domestication may be associated with the central oxytocin (OT) system. OT has been repeatedly shown to exhibit pro-social and anxiolytic eff ects rodents, dogs, humans and other species [1]. In our study, we used intranasal OT administration on Siberian tame foxes and non-selected one. It is well-known experimental domestication model of. Th e OT eff ect on behavior had been investigated in intermale interactions (triple cage aft er adaptation) and human contact (new enclosure). OT administration increased patterns of playful (crouches on paws), affi liative (friendly) behavior, motor (fast move) and mixed activity in male-to-male interactions in tame foxes, whereas in case of unselected foxes, OT administration increased behavior patterns associated with anxiety (latent time for home cage exit, freezing, total time in home cage). In fox-human interactions, OT administration had the greatest eff ect on increasing the time tamed fox stayed at less than a meter away from a human. It is this parameter that is the defi ning one in similar tests on dogs. Th e results allow to suggest that OT has a context-dependent eff ect rather than explicitly pro-social eff ect in the tests, therefore amplifying the perception of social conditions according to the social salience hypothesis of OT. OT eff ect is associated with emotional positive and negative animal behaviors toward human that could be related to the genotype. Such OT eff ect might separate animals into more or less tolerant to humans under the same early domestication conditions.