Effect of cyclosporin A on functional recovery in the spinal cord following contusion injury

Considerable evidence has shown that the immunosuppressant drug cyclosporin A (CsA) may have neuroprotective properties which can be exploited in the treatment of spinal cord injury. The aim of this study was to investigate the cellular environment within the spinal cord following injury and determine whether CsA has an effect on altering cellular interactions to promote a growth-permissive environment. CsA was administered to a group of rats 4 days after they endured a moderate contusion injury. Functional recovery was assessed using the Basso Beattie Bresnahan (BBB) locomotor rating scale at 3, 5 and 7 weeks post-injury. The rats were sacrificed 3 and 7 weeks post-injury and the spinal cords were sectioned, stained using histological and immunohistochemical methods and analysed. Using stereology, the lesion size and cellular environment in the CsA-treated and control groups was examined. Little difference in lesion volume was observed between the two groups. An improvement in functional recovery was observed within CsA-treated animals at 3 weeks. Although we did not see significant reduction in tissue damage, there were some notable differences in the proportion of individual cells contributing to the lesion. CsA administration may be used as a technique to control the cell population of the lesion, making it more permissive to neuronal regeneration once the ideal environment for regeneration and the effects of CsA administration at different time points post-injury have been identified.