Effect of whole body vibration on the myelination in the injured spinal cord of adult rats: quantification of luxol fast blue staining

Abstract

University, Varna, Bulgaria; Institute of Anatomy, Cologne University, Cologne, Germany; Email: stoyan.pavlov@mu-varna.bg)Whole-body vibration (WBV) is a relatively novel form of exercise used to improve neuromuscular performance in healthy individuals. Its usefulness as a therapy for patients with neurological disorders, in particular spinal cord injury (SCI), has received little attention in clinical settings and, surprisingly, even less in animal SCI models. We performed severe compression SCI at a low-thoracic level in Wistar rats followed by daily WBV starting 1, 7, 14 or 28 days after injury (WBV1, WBV7, WBV14 and WBV28, respectively) and continued over a 12-week post-injury period. As controls served rats euthanized in the first 2 weeks post SCI (subacute), with no WBV training (Sham), treated with passive flexion-extension (PFE) and intact animals. The changes in the average optical density (OD/µm2) of luxol fast blue stained longitudinal sections were used to assess the (re)myelination in the injured spinal cord. Three Regions of Interest (RoIs) were considered: (i) area with visible damage; (ii) proximal and distal region, adjacent to the damage (penumbra); (iii) visibly undamaged area distally and proximally to the lesion site. The average OD in the damaged areas was low in all animals as compared to intact animals; there were no differences among the treatment groups. The preliminary analysis of the ODs show that WBV7 and WBV14 enhanced remyelination in the penumbra and in the distant seemingly intact regions. Furthermore, OD in the distant regions of the WBV7 group did not differ from the OD in intact spinal cords. Further refinement of the method is needed in order to accurately evaluate this phenomenon.