Decrease in ER ɑ within the BNST of sexually naïve male rats following an encounter with a novel female

Behav Brain Res. 2023 Aug 16:114626. doi: 10.1016/j.bbr.2023.114626. Online ahead of print.ABSTRACTTestosterone and its metabolites facilitate male-typical social behaviors in sexually experienced animals. The metabolite estradiol acts on estrogen receptors (ERs) within the bed nucleus of the stria terminalis (BNST) to facilitate socio-sexual behaviors. While circulating testosterone does not increase in naïve males, aromatase-expressing neurons within the BNST of naïve males are necessary for sex recognition, suggesting that local estradiol production may be responsible. In the present study, we examined ERɑ-immunoreactive (ir) cell number within the brain of sexually naïve male rats 24hours after an encounter with a novel animal. As expected, males investigated females more than males. Additionally, males that encountered females had fewer ERɑ-ir cells within both anterior and posterior BNST compared to those who encountered a novel male or a non-social control. There were no changes within the AVPV, MPN, or MeA. The decrease in ERɑ-ir cell number within the posterior BNST only occurred in males that encountered estrus females whereas the decrease in the anterior BNST occurred only in males that encountered non-estrus females. Additionally, anogenital investigations were correlated with fewer ERɑ-ir cells in the posterior BNST, while cage sniffing correlated with the number ERɑ-ir cells in the anterior BNST. There were no differences in serum testosterone 45minutes ...

Source: Behavioural Brain Research - August 18, 2023 Category: Neurology Authors: Brianna M Bembenek Julia E Meyers-Manor Robin M Forbes-Lorman Source Type: research