Oxytocin signaling regulates maternally directed behavior during early life.

Oxytocin is essential in shaping social behavior across the lifespan. Although the role of oxytocin signaling in parental care has been widely investigated, little is known about its function in social behavior during early life. We studied the role of oxytocin in mouse pup social behavior during acute separation from the mother as well as upon reunion. The activity of oxytocin neurons was increased by acute maternal separation. Behaviorally, maternally separated pups emitted more ultrasonic vocalizations upon reunion, which were further modulated by nipple attachment behavior. These effects were attenuated by blocking the oxytocin receptor during maternal separation. Optogenetic silencing of oxytocin neurons during maternal separation disrupted vocal behavior during separation and reunion. Our findings reveal an important role of oxytocin in context-dependent vocal communication in mouse pups.