Lesions of the sexually dimorphic area disrupt mating and marking in male gerbils.

At the border between the medial preoptic area (MPOA) and the anterior hypothalamus (AH), gerbils have a sexually dimorphic area (SDA) that accumulates and responds to gonadal steroids. To assess the role of the SDA in the hormonal control of two sexually dimorphic behaviors, masculine sexual behavior and ventral scent marking, we studied changes in these behaviors in male gerbils after lesioning the lateral SDA or the entire SDA. Lateral SDA lesions disrupt openfield scent marking, at least temporarily, and produce long-lasting deficits in, but do not abolish, mating behavior. Lesioning both the medial and the lateral SDA produces more profound deficits in mating and marking. Similar lesions anterior or posterior to the SDA also impair these behaviors, but their effects are less severe. Thus the SDA is more important than other parts of the MPOA-AH in the control of mating and marking in male gerbils.