Abstract: Objective To observe the postnatal development characteristics of NG2 cells in spinal cord of rats. Method Immunohistochemistry(IHC) was applied to examine the morphologic characteristics of NG2 cells. Western blot was used to observed the expression of NG2 in spinal cord during the different postnatal developmental stages. Result IHC showed NG2 cells persistently existed during different postnatal developmental stages in spinal cord. There were a great number of NG2 cells with few processes and round or oval cell bodies at P1d. At P7d, a few NG2 cells can be detected with short processes in spinal cord. But at P21d,few NG2 cells were examined in the spinal cord. At P60d,NG2 cells with irregular cell bodies and 1~3 short processes were revealed. Compared with the cerebral cortex in the corresponding stages,NG2 cells in spinal cord possessed bigger soma, shorter and thin processes.Western blot showed that NG2 expression was highest at P1d ,declined at P7d and reduced significantly lowest at P21d,but increased atP60d.Conclusion The NG2 cells persistently exist in spinal cord and are different in cell number and morphology at the different postnatal development stages. It may start myelination from P7d to P21d.NG2 cells in spinal cord may be at an earlier stage in oligodendrocyte lineage.

Key words: NG2, spinal cord, development, rat