LESIONS IN MEDIAL PREOPTIC AREA AND BED NUCLEUS OF STRIA TERMINALIS -DIFFERENTIAL-EFFECTS ON COPULATORY-BEHAVIOR AND NONCONTACT ERECTION IN MALE-RATS

The goal of these studies was to assess the regulatory roles of the me dial preoptic area (MPOA) and the bed nucleus of the stria terminalis (BST) in sexual arousal, inferred from noncontact erection (NCE) evoke d in male rats by remote cues from estrous females. NCE and copulatory behavior were recorded before and after quinolinic acid or radiofrequ ency (RF) lesions were made in the MPOA (Experiments 1-3) or RF lesion s were made in the BST (Experiment 4). All males with MPOA lesions, pa rticularly in the rostral region, displayed severe deficits in copulat ion but little or no decrement in NCE. in contrast, BST lesions caused relatively moderate deficits in copulation, but they severely impaire d NCE. Animals with larger BST lesions, including rostral and caudal m edial regions, had more deficits in both copulatory behavior and NCE t han did males with smaller lesions confined to the rostral medial BST. These results suggest that (1) the MPOA is critical for copulatory be havior but not for NCE, (2) males that stop copulating after MPOA lesi ons are still sexually aroused by estrous females, and (3) the BST pla ys an important role in mediating NCE.