Oxytocin, Vasopressin, and Social Behavior: From Neural Circuits to Clinical Opportunities

Abstract

Oxytocin and vasopressin are peptide hormones secreted from the pituitary that are well known for their peripheral endocrine effects on childbirth/nursing and blood pressure/urine concentration, respectively. However, both peptides are also released in the brain, where they modulate several aspects of social behaviors. Oxytocin promotes maternal nurturing and bonding, enhances social reward, and increases the salience of social stimuli. Vasopressin modulates social communication, social investigation, territorial behavior, and aggression, predominantly in males. Both peptides facilitate social memory and pair bonding behaviors in monogamous species. Here we review the latest research delineating the neural circuitry of the brain oxytocin and vasopressin systems and summarize recent investigations into the circuit-based mechanisms modulating social behaviors. We highlight research using modern molecular genetic technologies to map, monitor activity of, or manipulate neuropeptide circuits. Species diversity in oxytocin and vasopressin effects on social behaviors are also discussed. We conclude with a discussion of the translational implications of oxytocin and vasopressin for improving social functioning in disorders with social impairments, such as autism spectrum disorder.

Keywords: autism; neuropeptides; oxytocin; social behavior; social communication; vasopressin.

Figure 1.

Neural circuits (inputs and outputs) of oxytocin (OXT) and arginine vasopressin (AVP). Blue arrows indicate OXT and AVP neuronal inputs, while red arrows indicate OXT and AVP neuronal outputs. Combined blue and red arrows indicate regions that share both inputs and outputs. HYP refers to hypothalamic regions outside the paraventricular nucleus (PVN) and supraoptic nuclei (SON) of the hypothalamus. A, PVN and SON OXT neurons. B, PVN and SON AVP neurons. C, Sexually dimorphic AVP neurons within the bed nucleus of the stria terminalis (BNST) and medial amygdala (MeA).

Figure 2.

Oxytocin (OXT) and arginine vasopressin (AVP) circuits that regulate social behavior. The paraventricular nucleus (PVN) and bed nucleus of the stria terminalis (BNST) contain OXT and AVP cell bodies that directly influence specific social behaviors: social recognition, social approach and reward, social communication, sexual behavior, parental behavior, and pair bonding and mate choice. A, PVN and BNST OXT circuits. B, PVN and BNST AVP circuits. Some contributions of AVP sources and sites of action are unknown, indicated by a short black arrow and “?”. All systems are not depicted for clarity.