TRIGEMINAL LESIONS AND MATERNAL-BEHAVIOR IN NORWAY RATS .1. EFFECTS OF CUTANEOUS ROSTRAL SNOUT DENERVATION ON MAINTENANCE OF NURTURANCE AND MATERNAL AGGRESSION

Cutaneous desensitization of the upper, rostral snout by bilateral section of the infraorbital nerves in lactating Norway rat dams markedly, but transiently, disrupted retrieval and licking of pups, nursing behavior, and fighting with a strange male intruder. Removal of the mystacial vibrissae, which provide major inputs to the infraorbital nerves, or cutaneous desensitization of the chin by bilateral sectioning of the mental nerves did not disrupt these behaviors. However, cutaneous desensitization of both the upper and lower rostral snout exacerbated and prolonged the effects produced by infraorbital denervation alone. The control of maternal behavior and aggression by somatosensory reflexes and the possible bases for rapid behavioral recovery after partial trigeminal sensory denervations are discussed.