Behavioral and neural mechanisms of learning in groups of a social cichlid fish

As animals navigate through their environment, they must integrate external stimuli with previous experience to guide behavioral decisions. In group living animals, these decisions are embedded in a social context that influences their interactions, access to resources, and ultimately, their behavior. To acquire and learn new information that is vital to their survival, individuals must successfully navigate social interactions that are often embedded in dominance hierarchies. Such hierarchies arise from dyadic relationships between dominant and subordinate individuals and confer fitness benefits to those of high rank. A great deal is known regarding the ultimate underpinnings of dominance, especially as it pertains to differences between dominant and subordinate individuals (reviewed in Chapter 1, along with a summary of the social learning field). However, we have much to learn regarding the neurobiological mechanisms through which individuals navigate these social hierarchies in order to learn and acquire new information that is critical for their survival, such as finding food. To begin to address this knowledge gap in understanding the neurobiology of learning in dynamic social groups, I conducted a series of experiments using the African cichlid fish, Astatotilapia burtoni. Males of this species form dominance hierarchies which are vital for gaining territories and access to reproductive opportunities. In chapter 2, I examined the unique social traits that differentiate dominant and subordinate males in social groups, and how these traits influence group learning and decision-making. In chapter 3, I examined the neural activity patterns that drive learning in a social and asocial context by quantifying immediate-early gene expression at different time points during the learning process. Finally, in chapter 4, I examined how these neural activity patterns in key brain regions, the putative homologues of the basolateral amygdala and hippocampus, vary with the extent of social stability during the learning process. Taken together, my research offers important new insights into the behavioral and neural mechanisms underlying social learning and suggests several directions for future study