A narrative review of motor control dual pathways: the corticospinal and reticulospinal tracts in synergy and differentiation

The corticospinal tract (CST) and reticulospinal tract (RST) represent the core descending pathways within the central nervous system for motor control. This review elucidates the anatomical and functional interplay. Anatomically, the CST and RST fibers are spatially proximate within the spinal cord and are integrated into a continuous regulatory axis via the corticoreticular pathway. Functionally, they exhibit both synergy and specialization: the CST primarily governs contralateral distal limb fine motor control, whereas the RST, operating in a bilateral mode, regulates axial and proximal body movements, postural stability, and adaptation to strength training. Notably, following CST damage (e.g., stroke or spinal cord injury), the RST demonstrates remarkable plasticity and serves as a critical substrate for functional compensation and recovery. Furthermore, an imbalance in CST-RST function has been implicated in the pathophysiology of conditions such as post-stroke spasticity and multiple sclerosis. Therapeutic strategies targeting the CST-RST network, including neuromodulation and molecular interventions aimed at promoting axonal regeneration and modulating network excitability, present promising new directions for the treatment of neurological disorders. Future research should focus on deciphering the specific interactions at the spinal interneuron level to advance the development of precise rehabilitation strategies.