The role of stress in natural populations

生存的基本现实之一是需要科普压力。它每天都在影响我们，可能损害健康，增加死亡率，并加速衰老速度。自然界中的动物可能也会受到类似的影响，尽管它们非常适合处理许多压力源。压力轴是神经内分泌系统的一个关键部分，它整合了环境变化，并通过它实现了繁殖、生长或储存能量的生活史决定。当今最具活力的研究领域之一是神经科学领域，特别是压力如何影响大脑和身体。几乎所有这些研究都建立在实验室大鼠和小鼠模型的基础上，但在自然界中，存在问题有许多解决方案。我的研究计划的目标是承担压力的作用，以帮助理解动物在真实的世界中应对压力情况的适应性，当这些不足时会发生什么（即当慢性自然压力源通过母体效应对生理学，生殖，大脑组织和人口统计学产生负面影响时），以及压力反应的变化有多快。因此，尽管我的发现可能也与人类的状况有关，但我的主要动机是了解压力轴在自然世界中为动物提供生活条件的作用，以及压力源如何改变它们的反应。这在北方尤其重要，因为那里由于全球变暖而发生了迅速变化。我的研究在加拿大各地进行，包括育空地区，并建立在我对野生哺乳动物的丰富经验之上。它针对五个关键领域：1）慢性压力对母体编程和压力轴表观遗传变化的作用; 2）压力对人口统计学的影响; 3）压力轴对繁殖成功的影响; 4）肾上腺在与冬季生存（间隔行为和冬眠）相关的生活史过程中的作用;以及5）压力轴的演变。

One of the fundamental realities of existence is the need to cope with stress. It impacts us all daily, can compromise health, increase the rates of mortality, and can accelerate the rate of aging. Animals in nature may be similarly affected, though they are exquisitely adapted to deal with many stressors. The stress axis is a pivotal part of the neuroendocrine system that integrates environmental change and through which life history decisions to reproduce, to grow, or to put energy into storage are implemented. One of the most vigorous areas of research today is the field of neuroscience and particularly how stress impacts the brain and body. Virtually all this research rests on a foundation of the laboratory rat and mouse models, yet in nature there are many solutions to the problem of existence. The objective of my research program is to bring to bear laboratory findings on the role of stress to help to understand the adaptations that animals in real world have in coping with stressful situations, what happens when these are insufficient (i.e. when chronic natural stressors negatively impact physiology, reproduction, brain organization, and demography through maternal effects), and how rapidly changes in the stress response can evolve. Thus though my findings may also have relevance to the human condition, my primary motivation is to understand the role of the stress axis in equipping animals for life in the natural world and how stressors modify their response. This is particularly relevant in the north, given the rapid changes occurring there because of global warming. My research takes place throughout Canada, including the Yukon, and builds on my extensive experience with wild mammals. It targets five key areas 1) the role of the chronic stress on maternal programming and epigenetic changes in the stress axis; 2) the impact of stress on population demography; 3) the impact of stress axis on reproductive success; 4) the role of the adrenals in life history processes associated with winter survival (spacing behavior and hibernation); and 5) the evolution of the stress axis.