Behavioural Endocrinology and Sexual Dimorphism of Brain and Behaviour

像身体的其他部分一样，由于性激素的作用，神经系统呈现出男性或女性的形态和功能。探索这些差异有助于我们了解神经系统是如何运作、专门化和自我重塑的。为了研究激素、神经系统和行为之间的相互关系，我们问了三个基本问题：(1)性激素如何作用于神经系统结构，使其呈现男性或女性形态？我们正在进行的研究计划重点放在脊髓、脑干和小脑的模型系统上，我们之前已经将这些系统与男性的性相关行为和性类固醇睾丸素的作用联系在一起。在拟议的研究中，我们将探索睾丸素对活跃在性环境中的交流行为的神经和基因控制的影响。此外，我们还将绘制之前未被充分研究的男性性回路脑干成分的性别差异图。在我们工作的基础上进行的其他研究表明，增塑剂双酚A(BPA)改变了脊髓中对性激素敏感的神经元的结构--接下来，我们将研究其他大脑区域的影响，并检查似乎具有类固醇作用的BPA替代物质的影响。我们还将研究这些物质对大脑结构的影响如何通过表观遗传修饰传递给后代。(2)睾酮等雄激素是如何调节行为过程的？几个拟议的实验探索了雄激素在产生超声波发声中的作用，超声波发声是大鼠的一种重要交流行为。我们感兴趣的是它们的信号特性，以及与荷尔蒙暴露所决定的社会和性发育的关系。在其他工作中，我们计划深入探索新的方法，通过模拟类固醇来改变大鼠认知、情感和性行为中正常性别差异的表达。(3)颠倒这种关系，行为和社交暗示如何改变性激素？主要转向人类，我们感兴趣的是生态上重要的环境因素--如优势竞争、人际关系、社会环境和生殖机会--如何引发男性和女性睾丸素释放的变化。据推测，这种机制是一种古老的适应机制，它协调生理和神经机制与环境机会。拟议的研究探索内分泌反应对社会输入的反应，如竞争、团队合作、社会排斥和配偶刺激。我们还将系统地评估性别认同在决定社会内分泌反应方面的影响，以及更传统的性别差异。

Like the rest of the body, the nervous system takes on a male or female form and function due to the actions of sex hormones. Exploring these differences helps us learn about how the nervous system functions, specializes and remodels itself. To study the reciprocal relationships between hormones, the nervous system, and behaviour, we ask three basic questions: (1) How do sex hormones act on neural structures to cause them to take on male or female form? Our on-going research program focuses on model systems in the spinal cord, brainstem, and cerebellum, that we have previously linked to masculine sex-related behaviour and the actions of the sex steroid testosterone. In proposed research we will explore testosterone's influence on neural and genetic control of communicative behaviours active in sexual contexts. Additionally, we will map sex differences in previously understudied brainstem components of the male sexual circuitry. Other studies build on our work showing that the plasticizer bisphenol A (BPA) alters the structure of sex steroid-sensitive neurons in the spinal cord – next, we will study effects in additional brain regions, and examine effects of BPA replacement substances that appear to have steroid-like actions of their own. We will also study how the effects of these substances on the structure of the brain are passed on to subsequent generations through epigenetic modification. (2) How do androgens like testosterone regulate behavioural processes? Several proposed experiments probe the role of androgens in the production of ultrasonic vocalizations, an important communicative behaviour in rats. We are interested in their signalling qualities, and relation to social and sexual development as determined by hormone exposure. In other work, we plan to thoroughly explore novel ways in which plasticizers, by mimicking steroids, alter the expression of normal sex differences in cognitive, emotional, and sexual behaviours in rats. (3) Reversing the relationship, how do behaviours and social cues alter sex hormones? Turning mostly to humans, we are interested in how ecologically-important environmental cues – like dominance competitions, relationships, social settings, and reproductive opportunities – provoke changes in testosterone release in men and women. Presumably, this mechanism is an ancient adaptation that coordinates physiology and neural mechanisms with environmental opportunities. Proposed studies probe endocrine reactivity in response to social inputs likes competition, teamwork, social exclusion, and mate stimuli. We will also systematically evaluate the impact of gender identity in determining social endocrine reactivity, alongside more traditional sex differences.*** *** *** **