THE MEDIAL AND LATERAL CELL GROUPS OF THE SEXUALLY DIMORPHIC AREA OF THE GERBIL HYPOTHALAMUS ARE ESSENTIAL FOR MALE SEX BEHAVIOR AND ACT VIA SEPARATE PATHWAYS

Male reptiles, birds and mammals do not copulate if the medial preopti c area (MPOA) is destroyed but the MPOA cell groups necessary for male sexual behavior were not known. Here, two cell groups essential for c opulation are identified in the sexually dimorphic area (SDA) of the g erbil (Meriones unguiculatus) MPOA. Bilateral cell-body lesions of eit her the medial or lateral SDA eliminated mating in sexually experience d male gerbils given testosterone. Nearby MPOA lesions did not. The me dial and lateral SDA affect sex behavior via separate pathways since l esioning the medial SDA on one side of the brain and the lateral SDA o n the other did not stop sexual behavior.