Population Differentiation in the Neural Substrates of Behavior

North Carolina State University, Raleigh NC

Investigators

Abstract

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.