Intravenous infusion of mesenchymal stem cells increased axonal signal intensity in the rubrospinal tract in spinal cord injury.

Limited spontaneous recovery occurs after spinal cord injury (SCI). However, current knowledge indicates that multiple forms of axon growth in spared axons can lead to circuit reorganization. Intravenous infusion of mesenchymal stem cells (MSCs) provides functional improvements after SCI with an increased axonal network. In this study, we examined how intravenous infusion of MSCs facilitates axonal connections in the rubrospinal tract (RST), one of the significant descending tracts, using AAV neuronal tracing techniques. Our finding demonstrated that infused MSCs significantly enhanced axonal signal intensity in the RST, not only around the injury site but also in the rostral and caudal regions, suggesting that neural circuit reorganization is facilitated.