Same-sex cohabitation under the effects of quinpirole induces a conditioned socio-sexual partner preference in males, but not in female rats

Pharmacol Biochem Behav. 2011 Oct;99(4):604-13. doi: 10.1016/j.pbb.2011.06.006. Epub 2011 Jun 16.

Abstract

The effects of the dopamine D2-type receptor agonist quinpirole (QNP) were examined on the development of conditioned same-sex partner preference induced by cohabitation in rats. In Experiment 1, males received either saline or QNP (1.25mg/kg) and cohabited during three trials with almond-scented stimulus males that were sexually naïve. In Experiment 2, males received six trials, and in Experiment 3 received three trials with sexually expert stimulus males. During a final drug-free preference test, males chose between the familiar or a novel male partner. In Experiments 1, 2 and 3 only QNP-treated males displayed a social preference for the familiar male, observed with more time spent together. In Experiment 3 males also displayed a sexual preference observed with more non-contact erections when were exposed to their male partner. In Experiment 4 we tested the effects on OVX, E+P primed females that received 1 systemic injection of either saline or QNP during three conditioning trials. In Experiment 5, females received 2 injections 12-h apart during each trial. Results indicated that both saline and QNP-treated females failed to develop partner preference. These data demonstrate that enhanced D2-type receptor activity during cohabitation facilitates the development of conditioned same-sex partner preference in males, but not in female rats. We discuss the implications for same-sex partner preferences.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Copulation / drug effects
  • Cues
  • Dopamine Agonists / pharmacology*
  • Estradiol / pharmacology
  • Female
  • Homosexuality / psychology*
  • Male
  • Odorants
  • Ovariectomy
  • Penile Erection / drug effects
  • Play and Playthings
  • Progesterone / pharmacology
  • Quinpirole / pharmacology*
  • Rats
  • Rats, Wistar
  • Receptors, Dopamine D1 / drug effects
  • Receptors, Dopamine D2 / drug effects
  • Sex Characteristics
  • Sexual Behavior, Animal / drug effects*
  • Sexual Partners
  • Smell / physiology
  • Social Behavior

Substances

  • Dopamine Agonists
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Quinpirole
  • Progesterone
  • Estradiol