Copulation-contingent aversive conditioning and sexual incentive motivation in male rats: evidence for a two-stage process of sexual behavior.

Male rats were tested for sexual incentive motivation and for copulatory behavior during acquisition of a copulation-malaise association. One group received an injection of 20 ml/kg of 0.15 M LiCl 1 min after ejaculation with a capelin oil-scented female and the other group received saline. LiCl was administered independently of copulation to this group. The subjects in the conditioned group showed reduced sexual motivation after two conditioning sessions, and copulation was almost extinguished after five sessions. At a postconditioning test with an unscented female, there was no group difference with regard to sexual motivation but the conditioned group still showed suppression of copulatory behavior. These data show that sexual incentive motivation and copulatory behavior can vary independently and that the associations copulation-malaise and scented female-malaise had been established during conditioning.