Secondary Motor Cortex Transforms Spatial Information into Planned Action During Navigation

Abstract

Fluid navigation requires constant updating of planned movements to adapt to evolving obstacles and goals. A neural substrate for navigation demands spatial and environmental information and the ability to effect actions through efferents. Secondary motor cortex is a prime candidate for this role given its interconnectivity with association cortices that encode spatial relationships and its projection to primary motor cortex. Here we report that secondary motor cortex neurons robustly encode both planned and current left/right turning actions across multiple turn locations in a multi-route navigational task. Comparisons within a common statistical framework reveal that secondary motor cortex neurons differentiate contextual factors including environmental position, route, action sequence, orientation, and choice availability. Despite significant modulation by context, action planning and execution are the dominant output signals of secondary motor cortex neurons. These results identify secondary motor cortex as a structure integrating environmental context toward the updating of planned movements.