Nestin mRNA expression after chronic compressive spinal cord injury in adult rats

Objective To investigate the regeneration of neural precursor cells in adult rats after chronic compressive spinal cord injury by analyzing the expressions of nestin and nestin mRNA. Methods Wistar rats (n=50) weighing 280~320 g were drilled at the root of spinous process of T12. The models of moderate and severe chronic compressive spinal cord injury as well as models at days 3 and 10 after decompression of severe chronic compressive spinal cord injury were made. Normal adult rats were used as control group. The slices of spinal cord tissues 5 mm from the edge of compression margin were used to observe the proliferation of neural precursor cells through immunohistochemical stain of nestin and nestin mRNA expression examined by In Situ Hybridization as well as quantitative computer image analysis. Results At moderate injury, severe injury and 3 days after decompression, nestin expressed significantly in white matter, gray matter and ependymal cells of the central canal (P0.05=. The nestin expressed the most significantly in the severe compression group (P0.01=. At severe injury and 3 days after decompression, nestin mRNA expressed significantly in ependymal cells of the central canal of spinal cord, nestin mRNA positive cells were widespread in white matter and gray matter, especially aggregating in the subventricular area, in Rexed's lamina Ⅸ and posterior horn (P0.05=. At moderate compression, nestin mRNA were predominantly expressed in Rexed's lamina Ⅸ and ependymal cells of the central canal of spinal cord (P0.05=. Moreover, nestin mRNA expression was also observed in the region of pial endfeet of the radial glial cells in white matter at moderate compression. Compared with normal rats, the nestin mRNA expression in the gray matter at 10 days after decompression was indistinctive (P0.05). There was no nestin mRNA expressed in controls. Conclusion Nestin mRNA expression in the spinal cord after spinal cord injury in adult rats demonstrates similar characteristics at developmental stages.