The Experimental Study Of Peripheral Nerve And Neural Stem Cells' Transplantation On Injured Spinal Cord

Objective: To study the affecting factors and curative effects by transplantation of peripheral nerve and heterologous embryonic neural stem cells, and to discuss some inconclusive problems which include: the appropriate animal model with injured spinal cord for peripheral nerve transplantation, proper source of peripheral nerve, the linking manners, the suitable environmental conditions for regeneration of focal injured spinal cord, the influence of neural nutritious factor, the transplanted neural stem cell's survival, differentiation and migration in the focal injured spinal cord, and the influence on the neural functions. Also to establish an effective treating method on injured spinal cord. Methods: 1. The transplantation of peripheral nerve: Hemisection models of spinal cords were fulfilled by cutting 4mm long spinal tissue from T8 to T9 of SD rats, and then exposed the intercostal nerves under the bilateral 9th, 10th ribs, the lesion of the spinal tissue was repaired using 6 to 8 intercostal nerves according to the different linking manners( proximal white matter to distal gray matter and proximal white matter to distal white matter). Absorbable glutin sponge was used in the control group instead of intercostal nerve. Some nerve growth factors and brain-derived neural nutritious factors were employed in the early stage after operation. The spinal regeneration of operated rats were observed functionally?and structurally in cage including, behavioral observations, slanting board tests and improved Tarlor's scores. The spinal sensory and motorial potential cc transmissions were monitored by somatosensory evoked potential and motor evoked potential. The structure of the transplanted nerve was observed by conventional histological slice, light microscope, scanning and transmission electron microscope. Axon's growth and functional recovery were monitored with a neural tracer (wheat germ agglutinin horseradish peroxidase). Positive cells of glial fibriooary acidic protein and S1~ protein were detected by immunohistological method. The operated region cell constitution was studied by cell density from imaging analysis. And the spinal structure was also observed by MR. 2. The transplantation of neural stem cell: neural stem cells were cultured from the brain tissue of hippocampal gyrus of the 14 days old SD rats, and then transplanted to the injured spinal cord hit by the different weight (Allen method) after passaging which labeled with 5- Bromodeoxyuridine and identification. The transplanted neural stem cell抯 survival, differentiation and migration in the injured spinal cord and the influence on the neural functional recovery were observed using the same methods above. Results: 1. The neural functional recovery after peripheral nerve transplantation is better than that of control groups, and there is no significant difference between the two operational manners, the spinal sensory and motorial potential can reach the end of injured spinal core, the tracer can be transit the proximal and distal section of the operated region, the transplanted nerves were fused with spinal core, and the neurons grew into the spinal core through anastomosis and transit the proximal and distal section. 2. The neural stem cell can survive in the injured spinal cord, differentiate into neurons and glia. established communi...