GIGA Neurosciences, University of Liège, 15 Avenue Hippocrate (Bat. B36), 4000 Liège, Belgium.
GIGA Neurosciences, University of Liège, 15 Avenue Hippocrate (Bat. B36), 4000 Liège, Belgium.
Horm Behav. 2023 Sep;155:105410. doi: 10.1016/j.yhbeh.2023.105410. Epub 2023 Aug 9.
Behavioral neuroendocrinology has largely relied on mammalian models to understand the relationship between hormones and behavior, even if this discipline has historically used a larger diversity of species than other fields. Recent advances revealed the potential of avian models in elucidating the neuroendocrine bases of behavior. This paper provides a review focused mainly on the contributions of our laboratory to the study of sexual differentiation in Japanese quail and songbirds. Quail studies have firmly established the role of embryonic estrogens in the sexual differentiation of male copulatory behavior. While most sexually differentiated features identified in brain structure and physiology result from the different endocrine milieu of adults, a few characteristics are organized by embryonic estrogens. Among them, a sex difference was identified in the number and morphology of microglia which is not associated with sex differences in the concentration/expression of neuroinflammatory molecules. The behavioral role of microglia and neuroinflammatory processes requires further investigations. Sexual differentiation of singing in zebra finches is not mediated by the same endocrine mechanisms as male copulatory behavior and "direct" genetic effect, i.e., not mediated by gonadal steroids have been identified. Epigenetic contributions have also been considered. Finally sex differences in specific aspects of singing behavior have been identified in canaries after treatment of adults with exogenous testosterone suggesting that these aspects of song are differentiated during ontogeny. Integration of quail and songbirds as alternative models has thus expanded understanding of the interplay between hormones and behavior in the control of sexual differentiation.
行为神经内分泌学在很大程度上依赖于哺乳动物模型来理解激素与行为之间的关系，即使这一学科在历史上使用的物种多样性比其他领域更多。最近的进展揭示了鸟类模型在阐明行为的神经内分泌基础方面的潜力。本文主要综述了我们实验室在研究日本鹌鹑和鸣禽的性分化方面的贡献。鹌鹑研究有力地证实了胚胎雌激素在雄性交配行为的性分化中的作用。虽然在大脑结构和生理学中确定的大多数性分化特征都源于成年期不同的内分泌环境，但有一些特征是由胚胎雌激素组织的。其中，鉴定出小胶质细胞的数量和形态存在性别差异，但与神经炎症分子的浓度/表达无关。小胶质细胞的行为作用和神经炎症过程需要进一步研究。斑马雀的鸣唱性分化不是由与雄性交配行为和“直接”遗传效应相同的内分泌机制介导的，已确定其不是由性腺类固醇介导的。还考虑了表观遗传贡献。最后，在成年期用外源性睾酮处理金丝雀后，鉴定出了这些鸟类在特定鸣唱行为方面的性别差异，这表明这些鸣唱行为方面在个体发育过程中是有差异的。因此，将鹌鹑和鸣禽作为替代模型进行整合，扩展了对激素和行为在控制性分化中的相互作用的理解。
