Project Summary Dr. Bond’s primary career goal is to run her own independent academic research group broadly investigating how principles of brain development can be used to understand and manipulate adult brain plasticity and regeneration. To accomplish this goal, Dr. Bond must gain training in single-cell biology techniques and advance her career development. The proposed research and career development plan has been specifically designed to fulfill Dr. Bond’s unmet training and prepare her for the next independent stage of her career. The plan includes research training in new technical skills, including ex-vivo time-lapse imaging, single-cell RNA-sequencing, and bioinformatic analysis of large-scale omics datasets, as well as career development training, including grant writing, lab management, mentoring, and scientific communication skills. The proposed research will be conducted at the University of Pennsylvania’s Perelman School of Medicine under the direct mentorship of Dr. Hongjun Song, a professor in the Department of Neuroscience and a world-renowned expert in neural stem cell biology. The Perelman School of Medicine boasts exceptional resources for trainees, including expansive core facilities, state-of-the-art laboratory space, and significant career development training and resources, which will together serve as the ideal environment for carrying out the proposed research and career development plan. The main objective of the proposed research is to understand the developmental process and molecular mechanisms that promote dentate gyrus neural stem cell quiescence and maintenance beyond development. A multipronged approach, including single-cell, candidate gene, and transcriptome-wide methods, will be used. First, clonal lineage tracing and time-lapse imaging experiments in Aim 1 will determine the timing and cellular behaviors that predict neural stem cell transition into quiescence during neonatal development. Then, genetic deletion experiments in Aim 2 will investigate how β1-integrin signaling is required for proper establishment of the quiescent neural stem cell pool during neonatal development, which could subsequently have long-term effects on adult neurogenesis. Finally, in Aim 3, single-cell RNA-sequencing of neural stem cells across neonatal development will reveal the molecular cascade that drives neural stem cell quiescence and maintenance during neonatal dentate gyrus development. The proposed research is well-aligned with the National Institute of Mental Health’s interest in basic research aimed at understanding the complex biological processes that direct neurodevelopment. Results from the proposed project will advance our understanding of neural stem cell maintenance and will have long-term applications for enhancing neural plasticity and neuroregeneration.