Oxytocin as a modulator of adaptive behavior: integrating ingestive and social mechanisms

Oxytocin (OXT) is synthesized in the hypothalamus and has well established roles in many physiological functions. OXT acts on G-protein-coupled receptors in the brain to influence a range of adaptive behaviors, including eating, social behavior and closely linked stress-related behaviors. The underlying mechanisms by which OXT influences these behaviors are still not well understood. Recent frameworks suggest that OXT may influence multiple adaptive behaviors at once to promote a contextually appropriate behavioral outcome. It is possible that this highly conserved neuropeptide subserves an evolutionary mechanism to promote behaviors that fulfill current homeostatic need and ultimately to promote survival. Here, we discuss the literature on OXT in ingestive behavior and consider overlapping mechanisms for OXT effects on social behavior. We highlight interactions between OXT and the hypothalamic melanocortin system and mesolimbic dopamine system as potential mechanisms for context-dependent behavioral selection. Finally, we suggest that OXT effects on behavior result at least in part from a positive shift in reward value of the stimuli that will fulfill the strongest homeostatic need at the time. Considering how these systems interact to influence behavior, particularly when multiple competing behavioral outcomes are possible, may facilitate the development of therapeutic targets across ingestive, social, and stress-related behaviors.