Enhaced D2-type receptor activity facilitates the development of conditioned same-sex partner preference in male rats

Conditioned same-sex partner preference in male rats is facilitated by oxytocin and dopamine: Effect on sexually dimorphic brain nuclei

“…Sexual training and surgery. As in our previous studies [17,18] males that functioned as stimulus received at least 10 trials of multi-ejaculatory sexual experience with receptive females prior to the start of the experiment, whereas experimental males were sexually naïve. In those previous studies we observed that cohabitation between two sexually naive males results in a strong same-sex socia preference, but less robust sexual preference.…”

“…For example, stimuli associated with nurture and juvenile play are rewarding only during periods of early development and can facilitate the crystalization of partner preferences that will be displayed after puberty [6][7][8][9][10]. In adulthood, other stimuli such as sexual reward [2,[11][12][13][14], cohabitation [15], mild stress [16] or even pharmacological manipulations [16][17][18][19] may function as reinforcers.…”

“…If repeated cohabitation occurs between two male rats and one of them is treated with QNP, a strong conditioned same-sex socio/sexual preference develops towards the cagemate in a subsequent drug-free preference test [17,18]. In our studies, same-sex partner preference occurs many days after the last pharmacological manipulation, and it is inferred when a male displays more social and sexual behaviors towards the male he previously cohabited with even if a sexually receptive female rat is concurrently available as a partner choice [17,18]. For example, conditioned males from previous studies preferred a male over a female as he spent more time together (70% of the time), displayed more visits, body contacts, and genital investigations.…”

Neurobiology of social attachments

“…One was a sexually receptive female and the other was the familiar male they cohabited with. Our results indicated that QNP-treated male rats (but not saline-treated) displayed a very robust social-sexual preference for the male, and ignored the receptive female, which demonstrates the powerful effect of the D2-type receptors activity on the development of intraspecific attachments (Cibrian-Llanderal et al, 2012).…”

“…monogamous vs. polygamous voles). Nevertheless, repeated exposure to social recognition paired with some types of reward can sensitize similar neural areas as observed in polygamous rats that express conditioned partner preferences after a period of learning (Coria-Avila et al, 2005Coria-Avila, 2007;Paredes-Ramos et al, 2011;Cibrian-Llanderal et al, 2012;Coria-Avila, 2012;Paredes-Ramos et al, 2012).…”