Objective      To explore the characteristics of oligodendrocyte precursor cells in cuprizone (CPZ)-induced demyelination models.       Methods      Eight-week old male C57BL/6 mice were randomly divided into a control group

a demyelination group (CPZ 6 weeks) and a remyelination group (CPZ 6 weeks + normal diet 2 weeks). The mice of the control group were fed with normal diet

and those of the demyelination group and remyelination group were fed with mix diet containing 0.2% CPZ for 6 weeks. Then the mice of the remyelination

group were given normal diet instead of CPZ for another 2 weeks. Luxol fast blue (LFB) staining and  transmission electron microscopy were used to test the  myelin sheath of corpus callosum (CC) in the brain. The expression levels of neuron-glial antigen 2 (NG2)

oligodendrocyte transcription factor 2 (Olig2) and glial fibrillary acidic protein (GFAP) in brain tissues were detected by immunohistochemistry and immunofluorescence.       Results      Compared with the control group

the myelin sheath significantly reduced

and the expression levels of Olig2

GFAP and NG2 in CC were significantly higher in the demyelination group (

P

0.01). The expression of NG2 in lateral septal nucleus (LSD) were higher than that in CC (

P

0.05). The expression levels of Olig2 and GFAP in the remyelination group were significantly higher than that in the control group (

P

0.05)

but were significantly lower than that in the demyelination group (

P

0.05).       Conclusion      Oligodendrocyte precursor cells cannot migrate to the site of injury in time. Sustained high level of astrocytes and reduction of Olig2 may be the influencing factors for myelin sheath repair disorder at the repair stage.