Motor Recovery after Chronic Spinal Cord Transection: A Proof-of-Concept Study evaluating a Combined Strategy.

BACKROUND- Chronic spinal cord (SC) injury is a hostile phase for regeneration known as a period of low activity with a progressive decline in neurological function. Several strategies have been investigated in this regard with no satisfactory results. OBJECTIVE- In this proof-of-concept study, we combine scar removal plus implantation of fibrin glue impregnated with mesenchymal stem cells, and immunization with neural derived peptides was included as well. METHOD- We performed three experiments, in which Sprague Dawley rats were subjected to a complete SC transection and, sixty days after the injury, the animals were randomly allocated into two groups for therapeutic intervention (TI): control and combination treatment (Comb-Tx). Sixty-three days after TI, we carried out different evaluations. RESULTS- Comb-Tx induced a significant locomotor and electrophysiological recovery. Furthermore, Comb-Tx promoted an increase in the expression of regeneration-associated genes and in the percentage of 5-HT+ fibers at the caudal stump of SC. Finally, we found a significant correlation of locomotor recovery with electrophysiological activity, expression of GAP43 and the percentage of 5-HT+ fibers. CONCLUSION- The combination therapy promotes motor and electrophysiological recovery in the chronic stage subsequent to a complete SC-transection. Likewise, it is capable of inducing the permissive environment to promote axonal regeneration.