One of the most important tasks of the nervous system is the generation of specific forms of movement as behavioral output, allowing animals or humans to interact with their surroundings appropriately according to motor plans and/or in response to influence from the environment. The motor system is broadly distributed across the nervous system, including areas close to actual motor program execution in the spinal cord, all the way up to regions of the nervous system involved in decision making and planning of motor acts. The brainstem is a key intermediary structure between higher motor centers and spinal circuits, and we have hypothesized that distinct subpopulations of brainstem neurons mediate selective motor programs. The goal of this work is to unravel key defining features of brainstem neurons involved in the regulation of diverse forms of movement, and to understand how a particular behavior is chosen over others. Our project will contribute to uncovering organizational principles of neuronal circuits in the motor output system of mice, as well as the contributions of these circuits to behavioral function.