Neuroendocrinology laboratory, GIGA Neurosciences, University of Liège, B-4000 Liège, Belgium.
Neuroendocrinology laboratory, GIGA Neurosciences, University of Liège, B-4000 Liège, Belgium.
Horm Behav. 2020 Sep;125:104827. doi: 10.1016/j.yhbeh.2020.104827. Epub 2020 Aug 14.
Estrogens play a key role in the sexual differentiation of the brain and behavior. While early estrogen actions exert masculinizing effects on the brain of male rodents, a diametrically opposite effect is observed in birds where estrogens demasculinize the brain of females. Yet, the two vertebrate classes express similar sex differences in the brain and behavior. Although ERα is thought to play a major role in these processes in rodents, the role of ERβ is still controversial. In birds, the identity of the estrogen receptor(s) underlying the demasculinization of the female brain remains unclear. The aim of the present study was thus to determine in Japanese quail the effects of specific agonists of ERα (propylpyrazole triol, PPT) and ERβ (diarylpropionitrile, DPN) administered at the beginning of the sensitive period (embryonic day 7, E7) on the sexual differentiation of male sexual behavior and on the density of vasotocin-immunoreactive (VT-ir) fibers, a known marker of the organizational action of estrogens on the quail brain. We demonstrate that estradiol benzoate and the ERβ agonist (DPN) demasculinize male sexual behavior and decrease the density of VT-ir fibers in the medial preoptic nucleus and the bed nucleus of the stria terminalis, while PPT has no effect on these measures. These results clearly indicate that ERβ, but not ERα, is involved in the estrogen-induced sexual differentiation of brain and sexual behavior in quail.
雌激素在大脑和行为的性别分化中起着关键作用。虽然早期雌激素对雄性啮齿动物的大脑有雄性化作用，但在鸟类中却观察到了相反的效果，雌激素使雌性的大脑去雄性化。然而，这两种脊椎动物类群在大脑和行为中表现出相似的性别差异。尽管 ERα 被认为在这些过程中在啮齿动物中起着主要作用，但 ERβ 的作用仍存在争议。在鸟类中，雌激素受体（s）在雌性大脑去雄性化中起作用的身份仍不清楚。因此，本研究的目的是确定在日本鹌鹑中，ERα 的特定激动剂（丙基吡唑三醇，PPT）和 ERβ（二芳基丙腈，DPN）在敏感时期（胚胎第 7 天，E7）开始时对雄性性行为的性别分化和血管加压素免疫反应（VT-ir）纤维密度的影响，VT-ir 纤维是雌激素对鹌鹑大脑的组织作用的已知标志物。我们证明，苯甲酸雌二醇和 ERβ 激动剂（DPN）使雄性性行为去雄性化，并降低中前脑核和终纹床核中 VT-ir 纤维的密度，而 PPT 对这些测量没有影响。这些结果清楚地表明，ERβ 而不是 ERα 参与了鹌鹑大脑和性行为中雌激素诱导的性别分化。
