PROJECT SUMMARY Sequences of neuronal activity are thought to underlie planning, preparation, and production of voluntary skilled behaviors. Dissecting how these premotor and motor sequences are functionally and synaptically integrated to support fluent, context-appropriate performance of natural behaviors is a major research challenge and a central goal of the BRAIN Initiative. The songbird premotor cortical structure HVC (letters used as proper name) has emerged as a prominent model system for studying how sparse neural sequences underlie the production of a precise, ethologically relevant behavior - birdsong. A single class of projection neurons in HVC is necessary for acute performance of birdsong. Yet, technical limitations associated with cell- type selective monitoring and manipulation of these neurons has hindered the ability to study how their neural sequences are functionally and synaptically integrated to support the planning, preparation and execution of behavior. This Diversity Supplement seeks to support the research and training of a new graduate student, Carlos Orozco, who will be working on aims 3 and 4 of the parent grant R01NS108424 (Neural sequences for planning and production of learned vocalizations). Mr. Orozco will be trainined in using calcium imaging, electrophysiological recordings and optogenetic manipulations in freely singing birds to test how diverse neural sequences in HVC underlie the planning, preparation and production of song. In addition, he will use single-cell optogenetics, calcium imaging, and circuit mapping methods to test the functional, synaptic and areal organization of this circuit. Drawing on training in a variety of cutting-edge approaches, this diversity Supplement aims to provide foundational training to a young scientist embarking on graduate school and provide insights into how diverse neural sequences are synaptically integrated to support fluent production of a voluntary skilled behavior.