PROJECT SUMMARY Over the last two decades there have been tremendous advances in in vivo neurophotonic technologies, which allow neuroscientists to visualize molecular, cellular and systems-level brain physiology and functions. For the last ten years, these technological efforts have been greatly facilitated by the BRAIN Initiative. However, this fast growth has widened the gap between the developers and the neuroscience community in need. This is because to properly use these novel tools, it is important to understand the underlying physical principles and have the practical skills in data collection and quantitative statistical analysis. Furthermore, each technique comes with its limitations, and understanding these limitations is critical for avoiding unconscious bias. The adoption and utilization of these neurophotonic technologies is, by nature, an interdisciplinary enterprise, forged between neuroscience, engineering, and the data sciences. As such, it also represents an ideal discipline around which to build a new training paradigm that incorporates team science, interdisciplinary thinking, communication, and business understanding. The mission of our Neurophotonics Research Training Program is to create the preeminent neurophotonics training program that will produce the next-generation of investigators capable of rigorously and creatively developing and applying photonics methods across a wide array of neuroscience sub- fields to advance our understanding of the brain in health and disease. Our trainees will gain the foundational knowledge of the field that will permit them to continue to grow with the field after their training, and efficiently translate their breakthroughs from the academic lab to real world applications. Our training program will fully support the broad range of exciting careers open to scientists today. In addition to building a field-defining neurophotonics curriculum, combining technical training, computational / data analysis, and critical thinking skills, we will provide robust training in the professional and operational skills required for success in this highly interdisciplinary field.