title: Effects of discrete lesions of the sexually dimorphic nucleus of the preoptic area or other medial preoptic regions on the sexual behavior of male rats.
abstract: The sexually dimorphic nucleus of the rat medial preoptic area (SDN-POA) has a volume five times larger in the adult male compared with that of the adult female. In the present study, the effects of discrete electrolytic destruction of the SDN-POA or other specific medial preoptic (MPOA) regions on masculine sexual behavior were determined in adult, sexually experienced male rats. Small lesions encompassing the SDN-POA had no effect on the maintenance of copulatory behavior. Lesions of similar size placed within the ventral or anterio-dorsal MPOA also did not consistently affect the display of masculine sexual behavior. However, animals that received small lesions within their dorsal MPOA showed a substantial, long-term decrease in number of mounts, intromissions, and ejaculations compared to these parameters in sham-lesioned control rats, thus indicating a lesion-induced disruption of those neural mechanisms mediating these behaviors. Collectively these data suggest that the SDN-POA is not critical for a full expression of male sexual behavior and that the dorsal MPOA may be more important than other MPOA regions for copulatory behavior.
mesh_terms: D000818:Animals; D001931:Brain Mapping; D003307:Copulation / Q000502:physiology; D004542:Ejaculation; D008297:Male; D011301:Preoptic Area / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012726:Sexual Behavior, Animal / Q000502:physiology*