Dopamine neurotransmission in the nucleus accumbens may be involved in oxytocin-enhanced grooming behavior of the rat.

Intracerebroventricular (ICV) infusion of a low dose of oxytocin enhanced novelty-induced grooming in male rats. The present experiments were undertaken to investigate whether dopamine neurotransmission in the nucleus accumbens is involved in this effect. Bilateral lesions of the nucleus accumbens by microinjections of 6-hydroxydopamine (6-OHDA) totally prevented the enhancement of grooming behavior after subsequent ICV infusion of oxytocin. Furthermore, bilateral injections of the dopamine receptor antagonist, haloperidol, into the nucleus accumbens completely suppressed grooming behavior of rats infused ICV with oxytocin. These results suggest that dopamine neurotransmission in the nucleus accumbens is involved in the behavioral response enhanced by the peptide.