LOW-INTENSITY MAGNETIC STIMULATION EXERTS PATTERN-DEPENDENT EFFECTS ON TISSUE REPAIR AFTER SPINAL CORD INJURY

Spinal cord injury (SCI) is a devastating condition leading to permanent sensorimotor deficits below the lesion site, associated with fibroglial scar formation, neural network disruption, and a chronic inflammatory environment. Effective treatments remain limited; nevertheless, neuromodulation has emerged as a promising strategy to enhance functional recovery and promote tissue repair after SCI. Among these approaches, repetitive magnetic stimulation (rMS) is a widely used therapy in humans that non-invasively modulates neural excitability and plasticity at both cortical and spinal levels. Previous studies have shown that trans-spinal rMS at high-intensity improves motor function and tissue remodeling in rodents. In this context, our study focuses on low-intensity rMS (LIrMS) and investigates how focal spinal stimulation patterns influence spinal cord repair after injury. Wild-type mice underwent SCI, followed by two weeks of either sham or trans-spinal LIrMS with three stimulation patterns. Locomotor recovery was assessed using the Basso Mouse Scale, and spinal cord samples were collected for immunohistochemistry and RNA sequencing. Our results indicate that LIrMS induces pattern-dependent effects on fibroglial scar reorganization, inflammatory processes, and myelin debris clearance. Transcriptomic profiling revealed distinct molecular signatures depending on the stimulation pattern, involving pathways related to fibrosis, immune and inflammatory regulation, vascular dynamics, and apoptotic processes. These data identify focal trans-spinal LIrMS as a promising neuromodulatory strategy to promote spinal cord repair, and pave the way for future investigations, including validation in a rat model whose pathophysiology after SCI is closer to humans.