In our daily lives, we explore and learn about the world around us through body movement. For instance, to find your keys in your bag, you use your fingers to touch each object in turn. When navigating a slippery environment, you coordinate your arms and legs to maintain your balance. These are natural, everyday examples of how movement is coordinated over the body, sequenced over time, and aligned with sensory input, but the way we typically study body movement and learning in the lab is quite different. Neuroscientists including ourselves have long relied on restraining the subject, to make it easier to position recording technology around the head and to suppress task-irrelevant movement. For instance, mice are commonly head-fixed during sensory tasks, which has advanced our understanding of how specific brain regions perform specific functions. However, a more integrative and naturalistic approach is needed to understand how multiple brain areas work together to coordinate complex and whole-body behavior. Thus, in this planning project, we will integrate existing technologies for detailed measurement of brain and behavior in mice while minimally impacting free movement. Specifically, we will implement 3D tracking of body posture (Aim 1), wireless multi-area neural recording (Aim 2), and wireless optogenetics (Aim 3). We will study the large-scale dynamics of populations of individually identified neurons, defined by cell type and projection pattern, at millisecond scale. We will use our machine learning tools to understand neural dynamics in our new freely-moving behavioral paradigms that probe sensorimotor integration and whole-body coordination in complex 3D environments. Specifically, we will measure the neural signals exchanged between motor cortex and other brain regions during free behavior. Previous work has shown that movement signals are widespread in the brain; our hypothesis is that movement signals are specifically routed where needed for each behavior. Completing this R34 will enable two future TargetedBCP R01s. One will study how motor and auditory cortex exchange sensorimotor signals for active sensing of sound, and another will study how left and right motor cortex coordinate movement of both sides of the body in 3D. Our investigative team has the experience to complete this project. The PI (Rodgers) has expertise in neuroengineering, systems neuroscience, animal behavior, electrophysiology, computational analysis, and optogenetics. Dr Berman (Co-I) brings theoretical expertise on identifying the statistical structure of animal behavior. We provide letters of support from experts in 3D tracking, motor cortex, wireless neurotechnology, and cell type-specific manipulation. Our research team includes diverse perspectives that allow us to innovate and to provide an inclusive training environment. In sum, this planning project will launch a new experimental/theoretical collaboration and integrate the tools we need to study the f...