RESUMO
To what extent does the reward value of sexual stimulation in females depend on ovarian hormones? The effects of estradiol benzoate (EB) and progesterone (P) were examined on the acquisition and expression of sexual reward induced by paced copulation and clitoral stimulation (CLS) in ovariectomized (OVX) rats. In experiment 1 we examined the expression of a pacing-induced conditioned place preference (CPP). Ovariectomized, hormone-primed rats were given experience with paced copulation associated with one side of a CPP apparatus. Changing hormonal status prior to the final CPP test did not alter pacing-induced CPP. However, subsequent partial extinction of CPP was observed only in rats primed with EB+P, a treatment previously shown to induce sexual desire and receptivity. In Experiment 2, significant CLS-induced CPP developed in ovariectomized rats regardless of hormone priming. Our results show that the expression of the sexual reward state induced by paced copulation, and CLS in particular, is independent of hormone priming. We propose that ovarian hormones sensitize sensory and motor pathways necessary for sexual behavior and stimulation to induce reward.
Assuntos
Hormônios Esteroides Gonadais/fisiologia , Recompensa , Comportamento Sexual Animal/fisiologia , Animais , Comportamento de Escolha/efeitos dos fármacos , Comportamento de Escolha/fisiologia , Copulação/efeitos dos fármacos , Copulação/fisiologia , Feminino , Hormônios Esteroides Gonadais/metabolismo , Hormônios Esteroides Gonadais/farmacologia , Aprendizagem , Ovariectomia , Ovário/metabolismo , Condicionamento Físico Animal/fisiologia , Postura/fisiologia , Ratos , Ratos Long-Evans , Comportamento Sexual Animal/efeitos dos fármacos , Fatores de TempoRESUMO
The effects of the opioid antagonist naloxone were examined on the development of conditioned partner preference induced by paced copulation in female rats. In Experiment 1, ovariectomized, hormone-primed rats were conditioned to associate scented and unscented male rats with paced and nonpaced copulation, respectively. Female rats in Experiment 2 associated albino or pigmented male rats with paced or nonpaced copulation. Naloxone or saline was administered before each conditioning trial. During a final drug-free preference test, female rats could choose to copulate with either a pacing related or unrelated male. Saline-trained female rats in the paired group copulated preferentially with the pacing-related male rat, whereas naloxone-trained female rats did not show a preference. The authors concluded that opioids mediated the conditioned partner preference induced by paced copulation.
