Copulatory behavior of sexually naive and sexually experienced male rats following removal of the vomeronasal organ.

The question addressed was whether removal of the vomeronasal organ (VNO) of the male rat would produce observable deficits in sexual behavior. Both sexually naive and sexually experienced males were used and each animal was given more than 12 hours to mate with a receptive female. Although sexual arousal was depressed in both groups, and depressed more among naive than experienced animals, every male was eventually aroused by the receptive female and eventually ejaculated. We conclude that while the VNO contributes to arousal it is not indispensable for arousal.