Recent advances in vasopressin signaling in the brain: from synapse to behavior to clinical translation

Arginine vasopressin (AVP) functions not only as a peripheral hormone but also as a potent neuromodulator that shapes neural activity across molecular, circuit, and behavioral levels. In the last few years, powerful tools such as optogenetics, fiber photometry, and receptor-specific imaging have revealed new dimensions of AVP signaling in synaptic plasticity, social behavior, and psychiatric vulnerability. This review integrates discoveries across three tiers, including (1) synaptic-level mechanisms that define how AVP sculpts excitatory–inhibitory balance, (2) behavioral pathways that link AVP activity to social cognition, stress, and emotion, and (3) translational advances identifying receptor-specific therapeutic and imaging strategies. Together, these findings position AVP as a key integrator of homeostatic and social functions in the brain and highlight its emerging clinical potential.