Oxytocin in the rat caudate nucleus influences pain modulation

► Intra-CdN microinjection of OXT receptor antagonist decreased the pain threshold. ► Intra-CdN microinjection of OXT increased the pain threshold. ► OXT receptor antagonist can attenuate the analgesic role induced intra-CdN administration of OXT. ► Pain stimulation could increase OXT concentration in CdN perfusion liquid. ► OXT in the CdN was involved in pain modulation via OXT receptors.