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

雄激素等类固醇对生物体的行为和繁殖成功有什么影响？ 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，对环境的反应行为变化可能很快，因此先于循环雄激素的变化。 这就提出了一个问题，即脑源性雄激素在调节行为方面是否很重要。一个特别迷人的现象是在蓝带虾虎鱼（Lythrypnus dalli），珊瑚居住的鱼，栖息在卡塔利纳岛海岸的沃茨。 这些鱼表现出一个haremic社会结构，其中一个大的男性主导一组女性。 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。 雄性通过扇起卵并保护它们免受捕食者的侵害来提供父爱。这项研究将解决大脑雄激素在调节两个生命史阶段中的作用：生殖转化和男性养育。 先进的资源将促进一个综合的，生物体水平的方法，包括生物化学，雄激素植入，脑药理注射，和激素测量，所有的背景下，在深入的行为观察野生捕捞的鱼在半自然的实验室环境中使用。 研究结果有望揭示，大脑（而不是性腺）是升高的雄激素的主要来源，用于调节生活史转变过程中的刻板行为模式。这些实验的结果将为理解社会行为以及类固醇驱动的细胞和分子机制奠定基础。 这项工作将涉及本科少数民族学生谁将学习宝贵的实验室技术和批判性思维技能的参与。 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、箭牌环境研究所和格鲁吉亚水族馆分享。

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.