Collaborative Research: Does responding to stressors prime greater resilience? Testing the long-term effects of challenges on behavior, physiology, epigenetic state, and fitness.

当面临重大挑战时——恶劣的天气、捕食者的攻击、受伤——生物体会产生协调的生理和行为应激反应。这种反应对于生存和从直接威胁中恢复至关重要。该项目将测试激活压力反应系统是否还有另一个被忽视的好处，即在更长的时间尺度上运行：为系统更好地应对未来的挑战做好准备。协同实验将解决一些基本问题，比如环境挑战何时以及如何增强应对未来挑战的能力，并检验这些影响是否会持续几代人。这项研究还将适应和改进新开发的传感器技术，该技术可以对自由生活的动物进行无创心率监测，这是一种可以在各个领域取得重大进展的工具。更全面地了解挑战的持续影响也将对其他领域有价值，包括保护和人类健康。此外，该团队将领导一个职业发展计划，该计划将实地研究实习（学生参与解决本提案中概述的研究目标）与实验室和课堂为基础的技能发展计划相结合，该计划面向对STEM领域的职业感兴趣的代表性不足群体的学生。这个机会旨在促进来自小型文理学院和大型研究型大学的学生之间的互动。这个项目将检验这样一个假设，即成年期经历的短暂挑战会为未来的挑战带来更大的弹性或稳健性，定义为回归或保持稳定状态的能力。研究将使用一个长期研究的树燕（Tachycineta bicolor）种群，其中可以从自由生活的个体中收集大规模的行为和生理数据。在研究的第一年，成年雌性将暴露于生态相关的挑战或模拟糖皮质激素应激反应。在接下来的几年中，将测量表型性状的多样性，以及与环境相关的表现和适合度。本研究设计将能够比较暴露于挑战的直接影响与暴露于对该挑战的反应的中介的影响。这些实验还将揭示应激源对行为、生理和适应性的长期影响是否由糖皮质激素和糖皮质激素诱导的DNA甲基化变化介导。本研究还将测试父母的暴露史是否会在挑战后的一年内影响后代的表型和适合度。通过在自由生活人群中进行有针对性的实验，结合行为、生理和表观遗传评估的综合方法，该项目将为开发和修订压力和表型可塑性的概念模型提供重要的见解。它还将扩大我们对行为机制的理解，生物体是如何被环境塑造的，以及亚生物体反应如何促进生物体的弹性和健壮性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

When faced with a major challenge – severe weather, the attack of a predator, an injury – organisms mount a coordinated physiological and behavioral stress response. This response can be vital for surviving and recovering from immediate threats. This project will test whether activating the stress response system has another overlooked benefit that operates over much longer time-scales: priming the system to respond better to future challenges. Coordinated experiments will address fundamental questions about when and how environmental challenges prime greater resilience to future challenges, and examine whether those effects persist across generations. This study will also adapt and refine newly developed sensor technology that enables non-invasive monitoring of heart rate in free-living animals – a tool that could yield considerable advances across fields. A more comprehensive understanding of the lingering impacts of challenges will also be valuable for other fields, including conservation and human health. Additionally, the team will lead a career development program that combines a field research internship – in which students participate in addressing the research objectives outlined in this proposal – with a laboratory- and classroom-based skills development program for students from underrepresented groups who are interested in careers in STEM fields. This opportunity is designed to foster interactions among students from a small liberal arts college and from a large research-intensive university.This project will test the hypothesis that transient challenges experienced in adulthood prime greater resilience or robustness to future challenges, defined as the ability to return to or maintain a stable state. Research will use a long-term study population of tree swallows (Tachycineta bicolor) in which large-scale behavioral and physiological data can be collected from free-living individuals. In the first year of study adult females will be exposed to either an ecologically relevant challenge or a simulated glucocorticoid stress response. In the following year(s) a diversity of phenotypic traits, and context-dependent performance and fitness, will be measured. This study design will enable comparison of the direct effects of exposure to a challenge with the effects of exposure to a mediator of the response to that challenge. These experiments will also reveal whether the long-term effects of stressors on behavior, physiology, and fitness are mediated by glucocorticoids and by glucocorticoid-induced changes in DNA methylation. This research will also test whether parental exposure history carries over to affect the phenotype and fitness of offspring produced in the year(s) after the challenge. By combining targeted experiments in a free-living population with integrative methods of behavioral, physiological, and epigenetic assessment this project will provide insights important for developing and revising conceptual models of stress and phenotypic plasticity. It will also broaden our understanding of the mechanisms of behavior, how organisms are shaped by their environments, and how sub-organismal responses contribute to organismal resilience and robustness.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.