Parental stress & offspring effects: exploring new models

暴露于剥夺或不利的早期养育环境，通常被称为“早期逆境”，已被证明对个人如何应对压力和学习有持久的影响。基于现有的动物模型，我们知道其中一些影响是直接由于大脑在发育的重要早期阶段发生的变化。例如，不断地将幼鼠从它们的母亲身边带走，会导致处理压力的神经激素系统（HPA轴）发生物理变化。具体来说，位于大脑区域的压力激素受体告诉身体“关闭”压力反应，在母亲分离的大鼠中减少。这种变化的最终结果是，这些动物更焦虑，可能更容易生病，并且随着年龄的增长，学习能力可能会受损。我建议在两个相对较新的动物模型中研究早期逆境的影响：尤卡坦小型猪（迷你猪）和欧洲八哥。迷你猪将作为一个有趣的对比，充分研究大鼠幼崽，因为小猪有更成熟的大脑在出生时。此外，猪学习各种空间任务的速度比老鼠更快，它们的学习过程可能与人类更相似。鸟类，如欧洲椋鸟，是一个有趣的比较时，调查如何“产前”的压力经历了母亲后来影响她的后代。这是因为，与哺乳动物不同，母鸟体内的应激激素只能在下蛋前形成蛋时直接影响雏鸟。因此，小型猪和鸟类模型使我们能够研究产前（生理）和产后（母亲）护理因素影响后代发育的方式的各自差异。这项研究可能会对从动物福利（例如，商业猪生产中的畜牧业），人类保健（例如，产前糖皮质激素治疗的建模效果），和儿童发育（例如，模拟儿童忽视或次优护理对学习和记忆过程的影响）。

Exposure to a deprived or adverse early rearing environment, often called "early adversity", has been shown to have lasting effects on how individuals both react to stress and learn. Based on existing animal models, we know that some of these effects are directly due to changes in the brain that occur during important early stages of development. For example, continually removing rat pups from their mothers causes physical changes in the neurohormonal system that deals with stress- the HPA axis. Specifically, receptors for stress hormones, located in brain regions that tell the body to "turn off" a stress response, are reduced in maternally-separated rats. The end effect of this change is that these animals are more anxious, may be more susceptible to disease, and may have impaired learning abilities as they age. I propose to study the effects of early adversity in two relatively new animal models: the Yucatan miniature pig (mini-pig) and the European Starling. The mini-pig will serve as an interesting contrast to the well-studied rat pup, since piglets have more mature brains at birth. As well, pigs learn various spatial tasks more quickly than rats, and their learning processes may be more similar to humans. Birds, such as the European Starling, are an interesting comparison when investigating how "prenatal" stress experienced by a mother later affects her offspring. This is because, unlike in mammals, stress hormones in the mother bird can only affect her chicks directly when she is forming the egg before it is laid. Thus, the mini-pig and bird models allow us to study the respective differences in the ways that prenatal (physiological) and postnatal (maternal) care factors influence offspring development. This research will potentially be of interest to areas ranging from animal welfare (e.g., livestock husbandry in commercial pig production), human healthcare (e.g., modeling effects of prenatal glucocorticoid therapy), and child development (e.g., modeling effects of child neglect or suboptimal care on learning and memory processes).