Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan.
Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan.
Neurosci Lett. 2021 Jun 11;755:135915. doi: 10.1016/j.neulet.2021.135915. Epub 2021 Apr 24.
The medial preoptic area, which plays an essential role in the control of sexual behavior in rats, contains a sexually dimorphic nucleus that consists of neurons expressing calbindin-D28 K (Calb) that is referred to as the CALB-SDN. The CALB-SDN is larger and contains more Calb neurons in males than in females. The physiological functions of the CALB-SDN are not fully understood; however, CALB-SDN neurons are activated during sexual behavior in males, suggesting that the male CALB-SDN is involved in regulation of sexual behavior. However, no information exists about the physiological functions of the female CALB-SDN. In the present study, we performed an immunohistochemical analysis of c-Fos, a neuronal activity marker, in the CALB-SDN of female and male rats that had copulated with conspecifics of the opposite sex to determine whether neurons of the female CALB-SDN are activated during copulation and whether the neuronal activity of the CALB-SDN differs between sexes. The numbers of c-Fos-immunoreactive cells with or without Calb-immunoreactivity (c-Fos/Calb and c-Fos/Calb cells) were greater in the CALB-SDN of rats that had copulated than in rats that had not copulated in each sex. Although the number of Calb cells in the CALB-SDN was smaller in females than in males, the increase in the number of c-Fos/Calb cells in the female CALB-SDN with copulation was comparable to that in the male CALB-SDN with copulation. The increase in the number of c-Fos/Calb cells in the CALB-SDN with copulation was more prominent in males than in females. These results suggest that CALB-SDN neurons are activated during copulation in both sexes. The patterns of neuronal activation in the CALB-SDN during copulation may differ between sexes.
内侧视前区在控制大鼠的性行为方面起着至关重要的作用，它包含一个性别二态核，由表达钙结合蛋白-D28K (Calb) 的神经元组成，称为 CALB-SDN。CALB-SDN 在雄性中比在雌性中更大，并且包含更多的 Calb 神经元。CALB-SDN 的生理功能尚未完全了解；然而，CALB-SDN 神经元在雄性的性行为期间被激活，这表明雄性的 CALB-SDN 参与了性行为的调节。然而，关于雌性 CALB-SDN 的生理功能尚无信息。在本研究中，我们对与异性交配的雌性和雄性大鼠的 CALB-SDN 中的神经元活性标志物 c-Fos 进行了免疫组织化学分析，以确定雌性 CALB-SDN 的神经元是否在交配期间被激活，以及 CALB-SDN 的神经元活性是否在性别之间存在差异。在每只大鼠中，与未交配的大鼠相比，已经交配的大鼠的 CALB-SDN 中具有或不具有 Calb-免疫反应性的 c-Fos-免疫反应性细胞（c-Fos/Calb 和 c-Fos/Calb 细胞）的数量更多。尽管雌性大鼠 CALB-SDN 中的 Calb 细胞数量少于雄性大鼠，但雌性大鼠 CALB-SDN 中与交配相关的 c-Fos/Calb 细胞数量的增加与雄性大鼠 CALB-SDN 中与交配相关的 c-Fos/Calb 细胞数量的增加相当。CALB-SDN 中与交配相关的 c-Fos/Calb 细胞数量的增加在雄性大鼠中比在雌性大鼠中更为明显。这些结果表明，CALB-SDN 神经元在两性的交配过程中被激活。CALB-SDN 中与交配相关的神经元激活模式可能在性别之间存在差异。
