Effects of dopamine receptor antagonists on ongoing maternal behavior in rats

The effects of different peripheral doses of four dopamine (DA) receptor an tagonists on general activity and maternal behavior were examined in lactat ing female rats. Administration of the classic D1-like and D2-like Da recep tor blocker haloperidol (0.1 and 0.05 mg/kg) disrupted pup retrieval and ne st-building behaviors and reduced motor activity. Pimozide (0.5 and 0.2 mg/ kg), which has more affinity for DA D2-like receptors, mildly disrupted pup retrieval while showing no significant influence on open-field behaviors. The putative DA D-4 receptor blocker, clozapine (1.5 and 1.0 mg/kg) reduced motor activity significantly, while only 1.0 mg/kg dose significantly decr eased percent of rats displaying nest building. The DA D1-like receptor blo cker SKF-83566 (0.2 and 0.1 mg/kg) significantly reduced pup retrieval, nes t building and motor activity. These results suggest a role for DA receptor s in ongoing maternal behavior that correlates directly with general activi ty. (C) 2001 Elsevier Science Inc. All rights reserved.