Exercise Engages Coordinated Neuron-Glia Signaling to Shape Spinal Cord Plasticity

Physical activity induces systemic benefits for brain and muscle function, but how the healthy spinal cord adapts to exercise remains largely unknown. Here, we combine bulk proteomics, single-nucleus RNA sequencing, and cellular communication inference to map exercise- induced molecular adaptations in the mouse lumbar spinal cord. Endurance training elicited robust baseline remodeling, dominated by glial transcriptional changes. Acute exhaustive exercise triggered biphasic responses: widespread metabolic and synaptic gene upregulation at 6 h followed by balanced suppression at 24 h, with trained animals exhibiting enhanced amplitude and faster resolution. Cell-cell communication analysis revealed that exercise reshaped signaling networks in both magnitude and composition. While glia emerged as primary transcriptional responders, cholinergic neurons--despite minimal transcriptional changes--were central signaling hubs, engaging various pathways with astrocytes, oligodendrocyte precursor cells, and oligodendrocytes in a training-dependent and temporally restricted manner. Glial-derived communication further diversified these responses, with astrocytes, oligodendrocytes, and microglia shifting toward pathways supporting synaptic remodeling, axon guidance, and growth factor signaling while dampening inflammatory cues. Together, these findings identify neuron-glia communication as potential driver of spinal cord adaptation to exercise, suggesting pathways through which glial plasticity may serve as a key mediator linking motor activity to spinal cord resilience. Significance StatementExercise confers broad benefits for neural and motor system health, yet how the healthy spinal cord adapts to physical activity is poorly understood. Using multi-omic profiling, we show that endurance training and acute exercise elicit coordinated transcriptional and signaling responses in spinal cord glia, with cholinergic neuron-glia communication emerging as a key upstream driver. These findings identify glial plasticity and neuron-glia crosstalk as a potential mechanism of spinal cord adaptation, providing a foundation for leveraging exercise-based strategies in neurological health and disease.