TRIGEMINAL LESIONS AND MATERNAL-BEHAVIOR IN NORWAY RATS .3. EXPERIENCE WITH PUPS FACILITATES RECOVERY

In lactating rats, upper snout desensitization by trigeminal denervati on severely impairs maternal behavior, with substantial recovery 12-24 hr later. The potential effects of interaction with pups on this reco very was investigated. Dams were subjected to bilateral infraorbital d enervation or sham surgery on Day 5 postpartum and observed for 30 min with 6 foster pups 24 hr later, after separation from pups for 4 or 2 4 hr. Long separation reduced likelihood of retrieval and nursing beha vior, infraorbital denervation reduced duration of pup licking, and th ese deprivations combined greatly increased latencies of pup sniffing and durations of facial self-grooming. Both conditions, and especially their combination, prolonged retrieval duration, the retrieval sequen ce being interrupted by other pup contact, such as licking. Thus, inte raction with pups and adequate trigeminal stimulation maintain normal maternal behavior These findings are possibly relevant to the normal d ecline of maternal responsiveness during late lactation and to other l esion-induced deficits. (C) 1997 John Wiley & Sons, Inc.