Early-life adversity and adult cognition: the starling as an experimental model.

在早年经历过恶劣环境的人-例如，出生体重低，家庭贫困或家庭破裂-更有可能在成年后经历抑郁，成瘾和行为问题。这表明，严酷的早期条件会诱发一种认知方式，包括增加悲观和冲动。人类对这种影响的证据必然是相互关联的。为了通过实验证明存在因果关系，需要动物模型。在这个项目中，我们将开发一种新的动物模型，用于研究早期生活条件对成年认知的影响，使用欧洲椋鸟。椋鸟有很多优点，它们是长寿的野生动物，在实验室中已经开发了认知措施。最重要的是，我们可以在自然环境中实验性地操纵早期环境的严酷性，通过将巢中的雏鸟数量减少到2只或增加到7只。我们将在诺森伯兰郡的农场建立32个扩大的和32个缩小的巢，并从每个巢中取出一只小鸡进入实验室，在那里我们将使用既定的认知任务来检查悲观和冲动。这些任务涉及动物必须将模糊的刺激解释为积极或消极（对于悲观主义），并且必须在立即和延迟奖励之间进行选择（对于冲动）。我们还将研究一个积极的电流环境可以在多大程度上补偿早期生活的恶劣条件，通过在测试阶段将一半的鸟类安置在贫瘠的环境中，另一半则安置在丰富的环境中。此外，我们将使用一些生物学措施来探索早期生活条件对成人表型的影响的机制。这些是生长曲线，应激激素皮质酮的反应性，氧化应激和端粒长度。每一个都与早期事件如何影响成年人，人类以及其他动物有关。这项研究将构成早期生活事件对成年人悲观主义和冲动性影响的第一个实验证据，并将开始阐明相关机制。这些结果对于理解贫困社区中抑郁、成瘾和行为障碍的过度负担的原因具有重要意义，并将有助于理解积极的成人环境在多大程度上可以减轻早期生活环境的影响。

People who experience a harsh environment in early life - for example, low birthweight, family poverty or family disruption - are more likely to experience depression, addictions and behavioural problems years later when they are adults. This suggests that harsh early conditions induce a cognitive style involving increased pessimism and impulsivity. The human evidence for such effects is necessarily correlational. To show experimentally that there is a causal relationship, an animal model is required. In this project, we will develop a novel animal model for studying the effects of early-life conditions on adult cognition, using European starlings. Starlings have many advantages; they are long-lived, wild animals, for whom cognitive measures in the laboratory have already been developed. Most importantly, we can experimentally manipulate the harshness of the early environment in a natural setting, by either reducing the number of chicks in a nest to 2, or increasing to 7. We will create 32 enlarged and 32 reduced nests at farms in Northumberland, and take one chick from each into the laboratory, where we will use established cognitive tasks to examine pessimism and impulsivity. These tasks involve the animal having to interpret an ambiguous stimulus as either positive or negative (for pessimism), and having to choose between immediate and deferred rewards (for impulsivity). We will also examine the extent to which a positive current environment can compensate for harsh conditions in early-life, by housing half of our birds in barren and half in enriched conditions during the testing phase. In addition, we will use a number of biological measures to explore the mechanisms underlying the impact of early-life conditions on adult phenotype. These are growth profile, responsivity of the stress hormone corticosterone, oxidative stress and telomere length. Each of these has been implicated in how early events impact on adults, in humans as well as other animals. This study will constitute the first experimental evidence for an impact of early-life events on adult pessimism and impulsivity, and will begin to elucidate the mechanisms involved. The results have important implications for understanding the causes of the excess burden of depression, addictions and conduct disorder in deprived communities, and will help understand the extent to which a positive adult environment can mitigate the effects of early-life environment.