Project Summary Sleep is thought to play a significant contribution in the consolidation of multiple forms of memories during development. Transient disruptions of sleep often lead to delays and losses in learned skilled behaviors. While research has made great progress in understanding the role of sleep in the hippocampal dependent learning of explicit memories, how sleep influences the synaptic circuits involved in learning perceptual and procedural memories is still poorly understood. Songbirds provide an unmatched opportunity to study sleep based consolidation of skilled motor behaviors. Juvenile songbirds learn their courtship song through extensive daily practice, producing tens of thousands of renditions by adulthood. Daily, auditory-feedback guided improvements in song are hypothesized to be consolidated nightly during sleep, enabling renewed vocal exploration and continued refinement of song performances through development. My predoctoral research seeks to identify the synaptic circuits involved in sleep-based consolidation of song and the long-term impact of transient disruptions in these circuits during song development. By combining in vivo pharmacological manipulations with machine learning-based approaches for segregating and analyzing changes in singing behavior, I have identified at least one nuclei governing the sleep-based consolidation of complex motor behaviors. Remaining work to be done during the F99 phase will focus on the specific contributions of individual premotor synaptic circuits using synapse-specific pharmacology in conjunction with pathway specific chemogenetics. Also during the F99 phase, I will follow up on unexpected findings to determine the evolutionary relevance of song diversity in mate choice. The K00 phase of this proposal will provide a specific plan to find an ideal mentor and research environment for enhancing my knowledge and technical skills of neuroinvasion and propagation of viruses leading to generation of novel viral vectors for the effective dissection of neural circuits. Together, the research and training detailed in the two phases of this proposal will allow me to achieve my long-term goal of engineering sophisticated tools to understand the molecular, cellular, and synaptic basis of learned complex motor behaviors as a tenured principal investigator.