Actions of sciatic nerve ligature on sexual behavior of sexually experienced and inexperienced male rats: effects of frontal pole decortication.

The action of the hyperalgesia produced by the loose ligature of the sciatic nerve on the sexual behavior of two groups of sexually experienced and inexperienced male rats was studied. The putative changes in the behavior induced by this manipulation were attempted to be counteracted by the removal of the anterior frontal cortex. Independently of the sexual experience, the ligature of the sciatic nerve did not modify any parameter of the sexual behavior, except for a slight prolongation of the intromission latency. Surprisingly, the removal of the cortical frontal pole resulted in drastic changes in the sexual behavior of sexually inexperienced male rats such as an increase in the intromission and ejaculation latencies and the postejaculatory interval. These changes were not observed in the sexually experienced group. Interestingly, the sciatic nerve ligature prevented the changes in the copulatory behavior produced by the frontal cortex removal. These results suggest that the hyperalgesia induced by the sciatic nerve ligature was unable to alter the sexual behavior. By contrast, the frontal cortex removal produced important changes in the sexual behavior that depend upon the previous sexual experience. All results are discussed on the bases of the neural control underlying the possible relationships between algesia and male sexual behavior.