Developmental expression of estrogen receptor beta in the brain of prairie voles (Microtus ochrogaster)

Here, for the first time, the expression of estrogen receptor beta (ER) is characterized in the brains of the highly prosocial prairie vole (Microtus ochrogaster). ER immunoreactivity was compared in weanlings (postnatal Day 21) and adult males and females. The results indicate several major findings. First, unlike ER, ER expression is not sexually dimorphic. Second, the adult pattern of ER-IR is established at the time of weaning, as there were no age-dependent effects on distribution. Finally, ER does not appear to be as widely distributed in voles compared with rats and mice. High levels of ER-IR were observed in several regions/nuclei within the medial pre-optic area, ventrolateral pre-optic nuclei, and in the hypothalamus, especially in the paraventricular and supraoptic nuclei. The visualization of ER in prairie voles is important as the socially monogamous prairie vole functions as a human relevant model system for studying the expression of social behavior and social deficit disorders. Future studies will now be able to determine the effect of treatments on the expression and/or development of ER in this highly social species. (c) 2015 Wiley Periodicals, Inc. Dev Psychobiol 58: 223-230, 2016.