Parental stress & offspring effects: exploring new models

暴露在缺乏或不利的早期养育环境中，通常被称为“早期逆境”，已被证明对个体对压力和学习的反应都有持久的影响。基于现有的动物模型，我们知道其中一些影响是由于大脑在重要的早期发育阶段发生的变化直接造成的。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--的生理变化。具体地说，压力荷尔蒙的受体，位于大脑中告诉身体“关闭”压力反应的区域，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，可能更容易患上疾病，随着年龄的增长，学习能力可能会受到损害。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：尤卡坦微型猪(迷你猪)和欧洲八哥。迷你小猪将与研究充分的小鼠形成有趣的对比，因为小猪出生时大脑更成熟。此外，猪学习各种空间任务比老鼠更快，它们的学习过程可能更类似于人类。在研究母亲经历的“产前”压力对后代的影响时，像欧洲八哥这样的鸟类是一个有趣的比较对象。这是因为，与哺乳动物不同，母鸟体内的压力荷尔蒙只有在产卵前形成蛋的时候才能直接影响到她的雏鸟。因此，迷你猪和小鸟模型使我们能够研究产前(生理)和产后(母体)护理因素影响后代发育的方式的各自差异。这项研究可能会对动物福利(例如，商品猪生产中的畜牧业)、人类医疗保健(例如，产前糖皮质激素治疗的模拟影响)和儿童发展(例如，忽视儿童或次优护理对学习和记忆过程的模拟影响)等领域产生潜在的兴趣。

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).