Experimental Study Of Treatment Of Spinal Cord Injury With Transplantation Of Lineage-restricted Neural Precursors In Rats

Background: Ever since the famous neuroanatomist Ramon y Cajal wrote in the early 20th century that the central nervous system does not regenerate once it is injured, this theory has been popularly accepted. However this concept changed as neural stem cells were segregated from fetal rat and adult rat's striatum, and as theirs multi-directional differentiation potential was detected. But, the defects of neural stem cell were recognized gradually as the study went deeply, such as poor survivorship and mainly differentiate into glial cells in non-neurogenesis regions. So, nowadays foreign scholars have transferred there study emphasis from neural stem cell into neutral precursor cell.Objectives: To investigate the therapeutic effectiveness of lineage- restricted neural precursors(NRP/GRP) transplanted into rat spinal cord after moderate contusion.Methods: Forty-eight adult female SD rats were randomly divided into four groups as operated control group(Group A), contused control group(Group B), culture medium control group(Group C), NRP/GRP engrafted group(Group D). Injury models were established by self-designed electronic impact device with the impacting force of 5g×10cm. BBB scale, inclined plane test and cortical somatosensory evoked potential (CSEP) was observed. Survival, migration and differentiation of engrafted NRP/GRP labelled with BrdU were also detected at 4 days, 2 weeks and 5 weeks after transplantation.Results: BBB scores and inclined plane scores of Group D were statistically higher at 4 weeks and 5 weeks respectively post-engraftment (P<0.05). CSEP wave of Group D showed no significant recovery at 5 weeks post-engraftment. Survival, migration and differentiation of engrafted cells in Group D were illustrated at 4 days, 2 weeks, and 5 weeks after transplantation respectively. At the last time-point, integrity of injured region for group D was improved, showing more optimal result than control groups.Conclusion: The lineage-restricted neural precursors can survive, migrate and differentiate into mature phenotypes:neuron, astrocyte and oligodentrocyte, after immediate transplantation into moderately contused rat spinal cord. Transplantation with NRP/GRP could facilitate recovery and reorganization of nerve fibre in moderate SCI models.