Population Differentiation in the Neural Substrates of Behavior

这个项目将研究大脑进化的详细性质。具体地说，大脑中调节求爱行为的部分将在一种研究得很好的鱼类--特立尼达孔雀鱼--的对比种群中进行研究。在自然界中，一些孔雀鱼种群存在于其他鱼类的存在，这些鱼是成年孔雀鱼的强大捕食者，而在屏障瀑布上方的其他种群则没有这些强大的捕食者。在强大的捕食者的存在下，雄性的颜色比较单调，求偶相对较少，但在没有这些捕食者的情况下，雄性的颜色更鲜艳，求偶的次数更多。由于早期的野外移植实验，已知当孔雀鱼从高度捕食环境转移到低捕食环境时，这些特征会迅速进化，但导致行为变化的大脑变化尚不清楚。为了解决这一进化变化的神经机制，将使用分子生物学和神经生物学方法对产生对脊椎动物求偶至关重要的激素(精氨酸血管催产素)的细胞进行比较。这项研究的具体目标是评估精氨酸催产素在使求偶行为适应当地捕食者环境中的可能作用。这项研究的总体目标是了解导致动物行为差异的大脑变化的详细性质。这里采用的研究方法将有助于将在理解影响动物行为的环境因素方面的进展与我们对大脑功能的理解方面的进展联系起来。鉴于我们对行为的基因组和神经基础的理解取得了快速进展，该项目产生的知识也可能有助于改善家养鱼类的繁殖性能。

This project will investigate the detailed nature of brain evolution. Specifically, the part of the brain that mediates courtship behavior will be studied in contrasting populations of a well-studied fish species, the guppy of Trinidad. In nature, some guppy populations exist in the presence of other fish that are strong predators on adult guppies, while other populations above barrier waterfalls are free of those strong predators. In the presence of the strong predators, males are drably colored and court relatively little, but in the absence of these predators, males are more brightly colored and court more. Because of earlier field transplant experiments, these characteristics are known to evolve rapidly when guppies are moved from a high-predation to a low-predation environment, but the brain changes that cause the change in behavior are not known. To address the neural mechanism of this evolutionary change, the cells which produce a hormone (arginine vasotocin) that is critical for courtship in vertebrate animals, will be compared using molecular biological and neurobiological methods. The specific goal is to assess a possible role for arginine vasotocin in adapting courtship behavior to the local predator environment.The general goal of this research is to understand the detailed nature of changes in the brain that underlie differences in animal behavior. The research approach taken here will help to link the progress in understanding the environmental factors shaping animal behavior with advances in our understanding of the functioning of the brain. Given rapid advances in our understanding of the genomic and neural bases of behavior, the knowledge generated by this project may also be useful in improving the reproductive performance of domestically grown fish.