Heterosexual experience prevents the development of conditioned same-sex partner preference in male rats

• Published in: Behavioural processes 2017-03, Vol.136, p.43-49
• Main Authors: Ramírez-Rodríguez, Rodrigo, Tecamachaltzi-Silvaran, Miriam B., Díaz-Estrada, Victor X., Chena-Becerra, Florencia, Herrera-Covarrubias, Deissy, Paredes-Ramos, Pedro, Manzo, Jorge, Garcia, Luis I., Coria-Avila, Genaro A.
• Format: Article
• Language: English
• Subjects: Animals; Conditioned stimulus; Conditioning; Conditioning (Psychology) - drug effects; Conditioning (Psychology) - physiology; Copulation; Copulation - drug effects; Copulation - physiology; Dopamine Agonists - administration & dosage; Dopamine Agonists - pharmacology; Experience; Gays & lesbians; Homosexual; Male; Males; Mating Preference, Animal - drug effects; Mating Preference, Animal - physiology; Preferences; Quinpirole; Quinpirole - administration & dosage; Quinpirole - pharmacology; Rats; Rats, Wistar; Receptors, Dopamine D2 - agonists; Sex; Sexual behavior; Studies
• ISSN: 0376-6357; 1872-8308
• DOI: 10.1016/j.beproc.2017.01.010

•Conditioned same-sex partner preference can develop in sexually-naïve male rats.•Here we conditioned same-sex preference in males with prior heterosexual experience.•Only sexually-experienced males failed to develop conditioned same-sex preference.•We discuss the effects of sexual experience on the prevention of same-sex preference. Sexual partner preferences can be strengthened, weakened or even drastically modified via Pavlovian conditioning. For example, conditioned same-sex partner preference develops in sexually-naïve male rats that undergo same-sex cohabitation under the effects of quinpirole (QNP, D2 agonist). Here, we assessed the effect of prior heterosexual experience on the probability to develop a conditioned same-sex preference. Naïve or Sexually-experienced males received either Saline or QNP and cohabited during 24h with a male partner that bore almond scent on the back as conditioned stimulus. This was repeated every 4days for a total of three trials and resulted in four groups (Saline-naïve, Saline-experienced, QNP-naïve, QNP-experienced). Social and sexual preference were assessed four days after the last conditioning trial in a drug-free test in which experimental males chose between the scented familiar male and a novel sexually receptive female. Results showed that Saline-naïve, Saline-experienced and QNP-experienced displayed a clear preference for the female (opposite-sex). By contrast, only QNP-naïve males displayed a same-sex preference. Accordingly, QNP-experienced males were not affected by the conditioning process and continued to prefer females. We discuss the effects of copulation and D2 agonists on the facilitation and/or disruption of conditioned partner preferences