Differentiation And Behavioral Effects Of Human GABA Energy Precursor Cells Graft In Normal Rats

Objective: To study the implantation of human GABA-energic spinal precursor cells in normal rats.Methods: GABA-energic spinal precursor cells were transplanted on the thoracic spinal cord of female SD rats.Then body weights after transplantation were recorded.Changes in motor function were assessed by BBB and ladder scores.The threshold of pain retraction in the lower extremities was measured by IITC at 1.5m and 3m time after transplantation,and the H-reflex was evaluated by EMG and the spasm was observed by frequency-dependent inhibition.Immunofluorescence staining was used to determine the proportion of survival,migration distance and degree of differentiation of transplanted cells.By intraperitoneal injection of CNO,the receptor of transplanted cells was activated and the cells were stimulated to secrete GABA transmitters,further verifying the influence of pain and spasm on normal rats.Results: After 1.5 months of transplantation,the cells survived successfully,with survival rate and migration distance.90% of cells still expressed DCX in large quantity at 1.5 month,while only about 12% cells expressed Neu N,a mature neuronal marker.There was no difference in pain threshold between sham group,vehicle group and graft group at 1.5 months,and there was no significant difference before and after CNO.EMG H reflex showed no difference between the groups,and did not change after CNO.By recording the body weight,it was found that the body weights of SD rats were all above 80% of the baseline value.There was no significant difference in BBB score among the three groups.The ladder error rate showed no significant difference between sham group,vehicle group and graft group.Three months after transplantation,more than 90% of the transplanted cells began to express mature neuron marker Neun.The cells begin to grow immature axons.A few of cells expressed the astrocyte marker SOX9.There was no difference in pain among the 3 groups,and no difference before and after CNO.There was also no difference in H reflex among the three groups,and no difference before and after CNO.Conclusion: In normal rats,transplantation of GABA-energic precursor cells can survive and differentiation,according to endogenous development program of neural precursor cells.The mature of neurons last for 3 months,and the survival of neurons has no obvious influence on the physiological function of normal rats itself.The survived cells had not changed the pain threshold the H reflex.The possible reason is that under normal circumstances,the rat's own loop structure and synaptic function is complete with marginal effects by transplantation of GABA-energic precursor cells.