Overview
- The study, published Nov. 13, 2026, reports a complete body-part-specific topography inside the mouse secondary motor cortex (M2) that was previously overlooked.
- Researchers used high-speed wide-field optical imaging of intrinsic resting-state fluctuations to detect small M2 zones whose spontaneous activity synchronized with known sensory-cortex body maps.
- Two-color wide-field mapping separated corticospinal neurons from other cortical populations and confirmed the signals originate within M2 rather than leaking from primary motor cortex (M1).
- Anatomical circuit tracing showed each M2 subregion is structurally connected to its matching sensory-cortex representation, and those M2 zones fire together during coordinated multi-effector movements.
- Authors say the methods and map could guide follow-up work on stroke and injury biomarkers, tests of circuit integrity, and biologically informed designs for dexterous robotics.