Advisor: Robert Liu, Ph.D. (Emory University; Georgia Institute of Technology)
Joseph Manns, Ph.D. (Emory University)
Christopher Rozell, Ph.D. (Georgia Institute of Technology)
Samuel Sober, Ph.D. (Emory University)
Garrett Stanley, Ph.D. (Georgia Institute of Technology)
LEARNING INFANT ASSOCIATED SOUNDS: A BEHAVIORAL PARADIGM TO INVESTIGATE SENSORY PLASTICITY IN A SOCIAL CONTEXT
Auditory cortical representations are shaped by diverse and complex experience dependent factors. In the pursuit to understand how these dynamic representations influence social behavior, auditory cortical researchers are turning to ethological paradigms whereby rodents form auditory associations though social interactions. One such ethological paradigm is the maternal mouse communication model, which has been used to investigate plasticity in auditory cortical representations of pup ultrasonic vocalizations. However, questions have recently emerged regarding the degree for which these representations are in fact shaped by social experience. It appears that we now need the ability to ``pair'' pup interaction with a novel sound that is under experimenter control. Additionally, this method of pairing needs to be done in such a way to allow for the characterization of auditory cortical activity. The development and validation of such a behavioral paradigm is the central aim of this thesis. We have developed a pairing paradigm where we use a novel sound to guide mice to a target arm at the end of a maze where they receive a pup reward. We found that early on in training mice follow a strategy that is not random but is based on returning to the last arm they received a pup. Over training mice shift from using this initial location-based strategy to using an auditory one where they use the delivered sound to seek out and retrieve pups. By silencing auditory cortical activity in mice after they had been conditioned to approach a novel sound for pup reward, we demonstrated that performance on the task significantly drops and that the mice become more likely to use their initial location-based strategy. Finally, we found that mother mice can learn this task faster than cocaring mice. From these results, the paradigm we have developed looks to be a valuable tool for investigating how auditory cortical representations can influence behavior in social contexts.