An-Najah Staff

Preweanling rats exhibit components of maternal behavior (MB) after brief periods of contact with neonates; the latency of onset of MB rises considerably after weaning. Oxytocin (OXT) stimulates MB in adult rats. The effects of intracisternal (IC) administration of OXT (2 micrograms) on pup-directed and other behaviors in preweanling and postweanling juvenile rats were tested. Compared with saline and no treatment, OXT significantly increased active holding of pups in preweanling but not postweanling juvenile rats. No other components of adultlike MB were stimulated by OXT. OXT also decreased inactive touching of pups and robustly increased selfgrooming in juveniles at all ages tested. It is concluded that OXT facilitation of active pup-holding and licking in preweanling rats may be an extension of OXT-induced self-grooming to pups and may also be related to OXT activation of MB in adult rats.