Combined Intrinsic and Extrinsic Neuronal Mechanisms Facilitate Bridging Axonal Regeneration One Year After Spinal Cord Injury

This study investigates methods to promote the regeneration of nerve fibers (axons) in the spinal cord after injury, even long after the initial damage. Researchers found that a combination of treatments can help these fibers regrow across the injury site. The approach involves stimulating the nerve cells themselves to grow and creating a supportive environment around the injury. This was achieved using peripheral nerve conditioning lesions, grafts of marrow stromal cells, and neurotrophic factor gradients. Importantly, the study demonstrates that these treatments can be effective even when started well after the injury, suggesting potential for therapies in chronic spinal cord injury cases. The intraneuronal molecular mechanisms recruited by delayed therapies mirror those of acute injury.

• 1
  Combinatorial therapies (peripheral nerve conditioning lesions, grafts of marrow stromal cells, and NT-3 gradients) promote axonal regeneration into and beyond a mid-cervical lesion site, even when administered 6 weeks to 15 months after SCI.
• 2
  Intraneuronal molecular mechanisms recruited by delayed therapies mirror those of acute injury, including activation of transcriptional activators and regeneration-associated genes.
• 3
  Axonal bridging beyond the lesion occurred only in animals that received combinatorial treatment with CLs, MSC grafts in the lesion cavity, and lenti-NT-3 injections.