1998 Volume 12 Issue 2 Pages 123-144
Schwann cells (SCs) have been shown to effectively promote axonal regeneration in both peripheral nervous system and central nervous system. We are testing the ability of Scs to enhance regeneration in adult rat spinal cord when they are present in guidiance channels grafted into transected cords. And we performed detailed kinematic analysis of recovery process using a computerized motion analysis system after Schwann cell transplantation into midthoracic area. SCs were purified in culture from adult rat sciatic nerve, suspended in Matrigel : DMEM (30 : 70), and seeded into semipermeable PAN/PVC guidance channels (2.6 mm ID x 8mm long, 50kDa MW cutoff) at a final density of 120 x 10^6 cells/ml. Adult Fischer rat spinal cords were transected at T8 and the T9 segment, the spinal cord was removed to create a 4 mm gap. The rostral and caudal stumps of the cord were each inserted 1 mm into the channel. One month after grafting, a vascularized tissue cable was present within the channel bridging the two ends of the spinal cord. Within the cable, numerous myelinated and unmyelinated axons were observed. Fast Blue retrograde tracing showed that the majority of neurons whose axons regenerated into the channel were located in spinal cord gray matter. The labeling could be traced 9 segments rostrally to C7 and 9 segments caudally to L5. Axons from dorsal root ganglion neurons also regenerated into the channel. Lack of immunostaining for serotonin (5-HT) and dopamine beta hydroxylase (DBH) indicated that supraspinal axons from raphe nuclei (5-HT immunoreactivity) did not grow into the channel. We conclude that SCs in guidance channels serve as a cellular bridge that stimulates axonal regeneration of both ascending and descending spinal cord neurons. And we confirmed restored gait after transplantation with computerized motion analysis system.
