Estradiol (17β-estradiol, E₂) is a crucial estrogen hormone that regulates sexual, cognitive, social and affective behaviors in various species. However, complex central nervous system (CNS) effects of E₂, including its activity in males, remain poorly understood. The zebrafish (Danio rerio) is rapidly becoming a powerful novel model system in translational neuroscience research. Here, we evaluate the effects of a single 24-h exposure to 20 μg/L of E₂ on behavioral and endocrine (cortisol) responses in adult male zebrafish. Overall, E₂ exerted pro-social effect in the social preference test, reduced whole-body cortisol levels, elevated exploration in the novel tank test and increased the shoal size in the shoaling test, indicative of an anxiolytic-like profile of this hormone in male zebrafish. Supporting mounting human and rodent evidence on the role of E₂ in behavioral regulation, the observed pro-social and anxiolytic-like effects of E₂ in male zebrafish reinforce the use of this aquatic organism in studying steroid-mediated CNS mechanisms of complex affective and social behaviors.

雌二醇（17β-雌二醇，E ₂）是一种重要的雌激素，可调节各种物种的性，认知，社交和情感行为。然而，对E _2的复杂中枢神经系统（CNS）效应，包括其在男性中的活性，仍然知之甚少。斑马鱼（Danio rerio）正在迅速成为转化神经科学研究中功能强大的新型模型系统。在这里，我们评估了成年雄性斑马鱼单次24小时暴露于20μg/ L E ₂对行为和内分泌（皮质醇）反应的影响。总体而言，E ₂在社会偏好测试中发挥了亲社会作用，降低了全身皮质醇的水平，在新型水箱测试中提高了探索度，并且在浅滩测试中增加了浅滩的大小，这表明这种激素在雄性斑马鱼中具有抗焦虑作用。支持安装人类和啮齿类动物证据E的作用₂在行为调节，观察到的亲社会和抗焦虑E对₂雄性斑马鱼加强使用这种水生生物的研究复杂情感的类固醇介导的中枢神经系统的机制和社会行为。