Comparison of sociability, parental care and central estrogen receptor alpha expression between two populations of mandarin voles (Microtus mandarinus)

Abstract

The socially monogamous mandarin vole (Microtus mandarinus) shows significant behavioral plasticity. We examined whether levels of sociability, parental care and central expression of estrogen receptor alpha differed between two populations with different ecologies. Our results show that males from the Chengcun population display significantly more amicable and less aggressive behaviors towards novel same-sex individuals compared to males from the second population of Xinzheng. Chengcun voles directed more licking behavior towards neonatal pups than did Xinzheng voles. Differences were also found in the number of estrogen receptor alpha-immunoreactive neurons. For example, Xinzheng males displayed significantly higher immunoreactivity than Chengcun males in the medial amygdala, medial preoptic area and ventromedial nucleus of the hypothalamus. Xinzheng females expressed higher levels of estrogen receptor alpha-immunoreactivity than Chengcun females in the medial preoptic area. Chengcun females exhibited significantly more estrogen receptor alpha expression than Xinzheng females in the bed nucleus of the stria terminalis. Our results indicate that mandarin voles from the Chengcun site possess monogamous traits, and animals from Xinzheng possess polygamous traits. It also appears that different social behavior and levels of parental care in these two populations may be associated with differences in estrogen receptor alpha-immunoreactive neurons.

Early Paternal Deprivation Alters Levels of Hippocampal Brain-Derived Neurotrophic Factor and Glucocorticoid Receptor and Serum Corticosterone and Adrenocorticotropin in a Sex-Specific Way in Socially Monogamous Mandarin Voles

“…Immunohistochemical and cell-counting procedures followed previous studies [35,36]. Briefly, floating sections were processed using primary antibody and streptavidin-biotin complex methods (SA1022; Boster Co., Wuhan, China).…”

Effects of castration on aggression and levels of serum sex hormones and their central receptors in mandarin voles (Microtus mandarinus)

“…Less social montane voles (Microtus montanus) display no sexual dimorphism for ERa expression. Similarly, highly social male prairie voles from Illinois and mandarin voles from Chenchun display less or no ERa than less social prairie voles from Kansas and mandarin voles from Zhengzhou in the BNST or in the MeA that regulate affiliation and aggression (Hnatczuk et al 1994;Cushing et al 2004;Wu et al 2011). The regulation of ERa may be a critical neuroendocrine factor in determining socially monogamous behavior.…”

Effects of cocaine on aggression and associated central ERα and oxytocin expression in ovariectomized and intact mandarin voles

“…Estrogen has been proven to modulate social behavior and aggressive behavior through estrogen receptor alpha (ERα) (Trainor et al 2008;Zhai et al 2008;Murakami et al 2011;Wu et al 2011). Decreased and eliminated ERα is associated with decreased aggression (Ogawa et al 1998;Cushing & Wynne-Edwards 2006;Trainor et al 2006b).…”

“…This rodent has an extended family group occupying a single burrow system, and shows a number of traits associated with a cooperative breeding system such as the delayed dispersal of juveniles and the presence of multiple successive litters within a nest (Smorkatcheva 1999;). In the lab, mandarin vole families have higher levels of social interaction via biparental, alloparental and affiliative behavior and stable pair-bonds (Wang et al 2005;Song et al 2010;Wu et al 2011Wu et al , 2013. The behavioral patterns of adult-adolescent interactions may be determined by adolescent development and prior familiarity (Wang & Tai 2012).…”

“…Male and female dominant voles engage in higher levels of approaching, investigating, self-grooming and exploring behavior than subordinates do (Qiao et al 2014). Unfamiliar female dyads display significantly more aggressive behavior and less affiliation than male dyads do (Zhai et al 2008;Wu et al 2011). Additionally, they display reinforcing effects in response to cocaine (Wang et al 2012a(Wang et al , 2012b).…”