TELENCEPHALIC CONNECTIONS OF THE SEXUALLY DIMORPHIC AREA OF THE GERBIL HYPOTHALAMUS THAT INFLUENCE MALE SEXUAL-BEHAVIOR

The sexually dimorphic area (SDA) of the gerbil hypothalamus is essent ial for mating in male gerbils. To determine if it affects mating thro ugh its connections with the ventral part of the lateral septal nucleu s (LSv), the caudal part of the medial bed nucleus of the stria termin alis (caudal BSTm), or the medial amygdala-amygdalohippocampal area (M A-AHi), these connections were severed. Unilateral cell-body lesions w ere made in the SDA and in the contralateral LSv, caudal BSTm, or MA-A Hi. Controls received the same lesions ipsilaterally. Other gerbils re ceived lesions in the caudal BSTm and contra- or ipsilateral MA-AHi. O nly contralateral lesions of the SDA and caudal BSTm severely impaired mating. Because contralateral lesions of the SDA and MA-AHi, or BSTm and MA-AHi, did not mimic this effect, the BSTm neurons that are neede d for male sexual behavior through their connections with the SDA do n ot simply relay information to or from the MA-AHi.