DISSERTATION RESEARCH: The role of neural androgens in the behavioral regulation of life-history transitions

像雄激素这样的类固醇对生物体的行为和繁殖成功率有什么影响？传统上，性腺被认为是循环雄激素的来源，从而调节行为。然而，通常情况下，对环境反应的行为变化可能很快，因此先于循环中的雄激素变化。这就提出了脑源性雄激素在调节行为中是否重要的问题。蓝带虾虎鱼（Lythrypnus dalli）是一种特别迷人的现象，它是一种栖息在圣卡塔利娜岛海岸附近水域的珊瑚栖鱼。这些鱼表现出一种双性恋的社会结构，在这种结构中，一只大的雄性鱼统治着一群雌性鱼。如果雄性离开群体，最具统治力的雌性会戏剧性地增加她的攻击性和领土行为，并转变为雄性。雄性通过扇卵和保护它们免受捕食者的侵害来提供父亲的照顾。本研究将探讨脑雄激素在调节两个生活史阶段的作用：生殖转化和男性养育。先进的资源将促进综合的、生物水平的方法，包括生物化学、雄激素植入、脑药理学注射和激素测量，所有这些都用于在半自然实验室环境中对野生捕捞鱼类进行深入的行为观察。研究结果有望揭示，大脑（而不是性腺）是在生活史转变过程中调节刻板行为模式的雄激素升高的主要来源。这些实验的结果将为理解类固醇驱动的社会行为以及细胞和分子机制奠定基础。这项工作将涉及少数民族本科生的参与，他们将学习有价值的实验室技术和批判性思维技能。通过教育推广活动，这项研究的结果将与行为神经科学中心、瑞格利环境研究所和乔治亚水族馆共同分享。

What effects do steroids like androgens have on the behavior and reproductive success of organisms? Traditionally, gonads are assumed to be the source of circulating androgens, thereby regulating behavior. Often, however, behavioral changes in response to the environment can be rapid and thus precede changes in circulating androgens. This raises the question as to whether brain-derived androgens are important in regulating behavior. A particularly fascinating phenomenon is seen in Bluebanded Gobies (Lythrypnus dalli), coral-dwelling fish that inhabit waters off the coast of Santa Catalina Island. These fish exhibit a haremic social structure, in which one large male dominates a group of females. If the male leaves the group, the most dominant female dramatically increases her aggressive and territorial behavior, and transforms into the male. The male provides paternal care by fanning eggs and defending them against predators. This research will address the role of brain androgens in regulating two life-history stages: reproductive transformation and male parenting. Advanced resources will facilitate an integrative, organism-level approach, including biochemistry, androgen implants, brain pharmacological injections, and hormone measurements, all used within the context of in-depth behavioral observations of wild-caught fish in a semi-natural laboratory setting. Findings are expected to reveal that the brain (rather than gonads) is the predominant source of elevated androgens for the regulation of stereotyped behavioral patterns during life-history transitions.The results of these experiments will lay a foundation for understanding social behavior as well as cellular and molecular mechanisms driven by steroids. This work will involve the participation of undergraduate minority students who will learn valuable lab techniques and critical thinking skills. Through education outreach activities, findings of this research will be shared in association with the Center for Behavioral Neuroscience, Wrigley Institute for Environmental Studies and the Georgia Aquarium.