Abstract

The long term inhibition of masculine sexual behavior after repeated ejaculations is known as sexual satiety.

To investigate the brain areas that may regulate sexual satiety, c-Fos expression was studied in different groups of sexually experienced male rats: controls not allowed to copulate, males allowed two or four ejaculations and animals allowed to reach sexual satiety.

Interestingly, males that ejaculated two or four times had similar c-Fos densities in all the evaluated brain regions, except for the suprachiasmatic nucleus.

Similarly, sexually satiated males had analogous c-Fos densities in all the evaluated brain areas independently of the number of ejaculations required to reach satiety.

Sexual activity (evidenced in males that ejaculated two or four times) increased c-Fos levels in the anteromedial bed nucleus of the stria terminalis, claustrum, entorhinal cortex, medial preoptic area, nucleus accumbens core, suprachiasmatic nucleus and supraoptic nucleus; however, sexual satiety did not modify c-Fos expression in these regions. Sexually satiated males had increased c-Fos densities in the ventrolateral septum and the anterodorsal and posteroventral medial amygdala, compared with animals allowed to copulate but that did not reach sexual satiety, and decreased c-Fos density in the piriform cortex.

These results suggest that the network that underlies sexual satiety is different from that which regulates copulation.