1. Department of Neurological Surgery and Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA.
2. International Collaboration on Repair Discoveries, Department of Orthopedics, University of British Columbia (UBC), Vancouver, British Columbia, Canada.
3. Research Resources Facilities, University of Louisville, Louisville, Kentucky, USA.
4. Vancouver Spine Surgery Institute, Department of Orthopedics, University of British Columbia (UBC), Vancouver, British Columbia, Canada.
5. Research Service, Robley Rex Veterans Affairs Medical Center, Louisville, Kentucky, USA.