The effects of oxytocin on social behavior and eye gaze: Insights from dog-human partnership.

Oxytocin (Oxt) plays a crucial role in forming stable social bonds and promoting social interactions in both humans and animals. During the long history of domestication, dogs have evolved advanced social communication, empathy, and a remarkable ability to perceive and respond to human emotions. Given the effective and intimate social interactions between dogs and humans, the laboratory Beagle dogs have been utilized to model mental disorders such as autism spectrum disorder (ASD). Indeed, ASD-associated Shank3 mutant dogs show impaired social interaction with both conspecifics and heterospecific humans, compromised face processing, and eye avoidance, faithfully recapitulating that in autistic individuals. Furthermore, exogenous Oxt ameliorates impaired social behaviors and visual attention in the ASD dog model, in support of studies in autistic individuals. As exogenous Oxt poorly penetrates blood-brain barrier, we speculate that combining exogenous Oxt administration with upregulation of the endogenous Oxt signaling might produce a better rescue effect of ASD symptoms. Further studies on animal models including dogs hold promise to better define Oxt-involved neural circuits underlying social behaviors.