Chapter 28 - Decision-Making in Fish: Genetics and Social Behavior

Abstract

In evolution, social behavior has been a potent selective force in shaping brains to control action. Social animals interact with others and their environment to survive and reproduce. To be successful, animals must acquire, evaluate, and translate information about their social and physical environments to decide what to do next. The resulting decisions can profoundly alter an animal's behavior and physiology, producing a diverse array of cellular and molecular responses. Clearly the brain controls behavior but how does an animal's behavior sculpt its brain? Using a particularly suitable fish model system with complex social interactions, we report how the social context of behavior shapes the brain and alters the behavior and neural circuitry of interacting animals. We have shown that social opportunities produce rapid changes in gene expression in key nuclei in the brain and these genomic responses prepare the individual to modify its behavior moving into a different social niche. Both social success and failure produce changes in neuronal cell size and connectivity in key brain nuclei. Understanding mechanisms through which social information is transduced into cellular and molecular changes provides a deeper understanding of the brain systems responsible for animal decisions.