Septal regulation of male sexual behavior in rats.

Involvement of septal nuclei in modulation of male sexual behavior in rats was investigated. Sexually active Wistar male rats were assigned to intact, sham, lateral septal nuclei lesioned (LSL), and medial septal nuclei lesioned (MSL) groups. All male rats were tested for sexual behavior in an arena in the presence of a sexually receptive female. Intromission and ejaculation latencies were increased, and mount, intromission, and ejaculation frequencies were decreased in the LSL group compared to the intact group. In contrast, mount and intromission latencies were decreased, and pursuit and mount frequencies were increased in the MSL group compared to the intact group. The results indicate that medial septal nuclei may inhibit and lateral septal nuclei may facilitate male sexual behavior in rats.