The influence of early-life stress on behaviour, physiology and fitness in the wild.

早期生活压力对野外行为、生理和健康的影响。

• 批准号: RGPIN-2014-05400
• 负责人: Newman, Amy
• 金额: $ 1.89万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611619
• 关键词: influence; early; life; stress; behaviour

My research tests the persistent effects of the early-life environment on individual physiology, behavior and fitness by integrating ecological and physiological methods in wild populations. Early-life conditions can have profound and lasting effects throughout an individual’s lifetime, however, the downstream influences on behaviour, physiology and fitness are not well understood. Stress and glucocorticoids have well-known and important effects on the development and function of the nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. Moreover, the HPA axis is a key physiological mechanism connecting an organism to its environment, through both acute responses and long-term adaptation, yet how stress influences fitness in wild populations is virtually unknown. Recent laboratory studies indicate that pre- or postnatal stress and/or glucocorticoid treatment have detrimental effects on the brain, behaviour and HPA axis in adult offspring. Although, if parents are adapting offspring to best match future environmental conditions, these apparent detrimental effects may, in fact, facilitate survival and reproduction in a stressful environment. To investigate the manifestation of early life stress in adulthood and the persistence across generations requires the ability to follow marked individuals within long-term populations. My students and I will work to understand the ecological and physiological long term effects of the early life environment by conducting experimental field studies in two populations. First, using a long-term marked population of Savannah sparrows (Passerculus sandwichensis) on Kent Island NB, we will investigate the effect of the early environment on physiology, song behaviour and fitness by measuring natural individual variation among chicks in their hormonal profiles (glucocorticoids, testosterone, estradiol), stress physiology, and body condition. In individuals that survive and return to breed on the island, we will measure adult stress physiology, song behaviour, survival, and reproductive output. Our second general study is a marked population of deer mice (Peromyscus maniculatus) in Algonquin Park, Ontario, where we will test hypotheses related to natal population density, maternal behaviour and downstream effects on offspring behaviour and physiology. Recent work in small mammals has demonstrated that population density is positively correlated with maternal stress hormone levels and that maternal behaviour is affected by population density. And while it is known that behavioural effects in offspring due to the maternal environment are epigenetically transmitted and F1s have an altered HPA axis in adulthood, it is not clear whether these effects persist across multiple generations and, importantly, what the consequences are for offspring fitness. In both of these populations, we will also use published genomic information for closely related conventional lab animals (zebra finch and lab mice) to develop cutting edge epigenetic tools to investigate a novel mechanism for the multigenerational transmission of signatures of the pre- and post-natal environment. Overall, these are rare opportunities to test unique predictions related to physiological and fitness consequences of early life stress. Further, because the HPA axis is a primary mediator of an organism’s response to its environment, understanding the mechanisms by which maternal stress affects HPA axis development and function is critical as more and more wild populations are being exposed to anthropogenic factors that may affect HPA function and influence fitness.

我的研究测试早期生活环境对个人生理，行为和健身的持续影响，通过整合生态和生理方法在野生种群。早期生活条件可以在个人的一生中产生深远而持久的影响，然而，对行为，生理和健康的下游影响还没有得到很好的理解。应激和糖皮质激素对神经系统和下丘脑-垂体-肾上腺（HPA）轴的发育和功能具有众所周知的重要影响。此外，HPA轴是通过急性反应和长期适应将生物体与其环境联系起来的关键生理机制，但压力如何影响野生种群的适应性几乎是未知的。最近的实验室研究表明，出生前或出生后的压力和/或糖皮质激素治疗对成年后代的大脑，行为和HPA轴有不利影响。虽然，如果父母正在调整后代以最好地适应未来的环境条件，这些明显的有害影响实际上可能有助于在压力环境中的生存和繁殖。要研究成年后早期生活压力的表现及其在几代人中的持续性，需要能够长期跟踪群体中的标记个体。 我和我的学生将通过在两个人群中进行实验性的实地研究，来了解早期生活环境对生态和生理的长期影响。首先，使用一个长期的显着人口的萨凡纳麻雀（Passerculus pastichensis）的肯特岛NB，我们将调查的影响，早期环境的生理，歌曲的行为和健身通过测量自然的个体差异小鸡在他们的激素配置文件（糖皮质激素，睾酮，雌二醇），应激生理和身体状况。在存活并返回岛上繁殖的个体中，我们将测量成年应激生理学，歌曲行为，生存和生殖输出。我们的第二个一般性研究是一个显着的人口鹿小鼠（Peromyscus maniculatus）在阿尔冈琴公园，安大略，在那里我们将测试假设纳塔尔人口密度，母亲的行为和下游影响后代的行为和生理。最近对小型哺乳动物的研究表明，种群密度与母体应激激素水平呈正相关，母体行为受种群密度的影响。虽然已知母体环境对后代的行为影响是表观遗传传递的，并且F1在成年期具有改变的HPA轴，但尚不清楚这些影响是否会持续多代，重要的是，对后代健康的影响是什么。 在这两个群体中，我们还将使用已发表的密切相关的传统实验室动物（斑胸草雀和实验室小鼠）的基因组信息来开发尖端的表观遗传工具，以研究产前和产后环境的多代传递的新机制。总的来说，这些都是难得的机会来测试与早期生活压力的生理和健康后果相关的独特预测。此外，因为HPA轴是一个生物体的反应，其环境的主要介质，了解母亲的压力影响HPA轴的发展和功能的机制是至关重要的，因为越来越多的野生种群被暴露于人为因素，可能会影响HPA功能和影响健身。