Abstract: Differences in the social behavior of monogamous and polygamous rodents may be related to estrogen receptor subtypes (ERs). The distribution of estrogen receptor α (ERα) and β (ERβ) immunoreactivity in polygamous rats and mice, and ERα immunoreactivity in the central nervous system of monogamous male prairie voles, have been reported, but no data on the ERβ distribution in monogamous voles is available. In the present study, the numbers of ERα and ERβ immunoreactive (IR) cells in the forebrain of male and female mandarin voles (Microtus mandarinus) were compared using immunocytochemistry. We found that ERα-IR and ERβ-IR cells were mainly found in nuclei in mandarin voles. ERα-IR and ERβ-IR cells were widely distributed throughout the forebrain and expression overlaps in many forebrain areas. However, the number of cells and degree of receptor expression per cell were different for each ER subtype. In the medial preoptic nucleus (MPN), bed nucleus of the stria terminalis (BNST) and medial amygdaloid nucleus (MeA) females had a higher ERα density than did males. The opposite pattern was found in the MPN and BNST where males had a higher ERβ density than did females. These results provide an important neuroanatomical basis for enhancing our understanding of how estrogens work through ERα and ERβ to regulate important processes including social behavior.

Key words: Estrogen receptor α (ERα), Estrogen receptor β (ERβ), Mandarin vole, medial preoptic nucleus (MPN), bed nucleus of the stria terminalis (BNST)

摘要： 单配制和多配制动物社会行为有差异，这些差异可能与雌激素受体类型有关（ERs）。虽然多配制大鼠和小鼠中枢神经雌激素受体α（ERα）和β（ERβ）免疫反应在大脑的分布已有报道，单配制雄性草原田鼠中枢神经ERα的分布也有报道，但单配制田鼠ERα和（或）ERβ在雌性和雄性分布差异未见报道。本研究对雄性和雌性棕色田鼠前脑区域ERα和ERβ免疫反应（IR）细胞数量进行比较。研究结果表明：（1）免疫反应主要分布在细胞核中。 （2）ERα-IR和ERβ-IR细胞广泛分布于整个雌性和雄性前脑区域，在许多脑区表达有重叠。然而，不同受体在雌雄不同脑核中的分布数量是不同的。（3）ERα 和ERβ的分布存在性别差异。例如，雌性ERα在视前核中部（MPN），终纹床和（BNST）和杏仁内侧核（MeA）比雄性多，相反雄性ERβ在MPN和BNST比雌性多。这些研究结果可能为我们理解如何通过ERα和ERβ调节动物的社会行为，及雌性和雄性社会行为的差异提供一个重要的神经解剖学基础。

关键词: 雌激素受体α, 雌激素受体β, 前脑；单配制田鼠, 棕色田鼠