The reward generated by social interactions is critical for promoting prosocial behaviors. Here Hung and colleagues present evidence that oxytocin release in the ventral tegmental area, a key component of the brain’s reward circuitry, is necessary to elicit social reward. During social interactions, activity in paraventricular nucleus oxytocin neurons was observed to be increased. Direct activation of these neurons in the paraventricular nucleus or their terminals in the ventral tegmental area also enhanced prosocial behaviors. Conversely, inhibition of paraventricular oxytocin axon terminals in the ventral tegmental area decreased social interactions. Specifically, oxytocin increased excitatory drive onto reward-specific ventral tegmental dopamine neurons. This report demonstrates that oxytocin promotes prosocial behavior through direct effects on dopamine neurons, providing insight into how social interactions can generate rewarding experiences.
Hung LW, Neuner S, Polepalli JS, Beier KT, Wright M, Walsh JJ, Lewis EM, Luo L, Deisseroth K, Dölen G, Malenka RC: Gating of social reward by oxytocin in the ventral tegmental area. Science 357(6358): 1406-1411 (2017).