Which specific ventral spared interneuron populations take part in spinal tissue reorganization after a traumatic injury (TSCI) has not been clarified yet. We hypothesize that these cells could reactivate developmental processes to be able to form new connections, and that this process could help us to characterize them after lesion. qPCR results indicated a potential re-expression of the transcription factor Vsx1, (which in a normal situation is transiently expressed at early embryonic stages in an intermediate V2 interneurons compartment and absent in the adult spinal cord) 2 weeks after TSCI. To confirm these results, thoracic contusions (t10-t11) were performed in adult transgenic mice, where the reactivation of Vsx1 after the injury (if exist) could be detected by the inducible expression of tdTomato (Vsx1-CreERT2xRosa26R-tdTomato). At day 5 post-injury, animals received a Tamoxifen treatment, to activate the Cre protein specifically in cells where the reactivation of Vsx1 would take place. One-month post-injury, results showed an increase in the number of positive tdTomato structures both rostrally and caudally to the lesion that seem to belong to V2a INs (Chx10+Zfhx3+) in comparison to sham animals (with the same genotype and receiving the same tamoxifen dosage). Thus, Vsx1 is not re activated after TSCI, but tdTomato expression can be used for the further characterization of the V2 specific subpopulations that could be implicated in neural circuitry restructuring after a TSCI. Ongoing work in the lab is focused on the confirmation of these results and additional characterization of other subpopulations maybe involved in this tissue reorganization.