Objective:To investigate the effect of microenvironment of normal neurons and neurons expressing seizure-like discharge induced by free-magnesium extracellular fluid culture on the differentiation of oligodendrocyte precursor cells(OPCs)

and to explore the influence of epileptic seizure on the remyelination. Methods:OPCs were purified on the 3rd day or the 4th day of proliferating phase. According to the proportion of additional neuronal medium in which neurons survived in the total medium

objects were divided into three levels:1/8

1/4

1/2;and each level was subdivided into three groups:OPC differentiation medium(ODM)group

OPC differentiation medium +corresponding proportion of induced seizure discharge neuron medium(ODM +INM) group

OPC differentiation medium +corresponding proportion of normal neuron medium(ODM+NNM)group. PDGFRα

CNPase and MBP transcription expressions of oligodendrocyte cells on the 3rd day

5th day

7th day of differentiation phase were detected by q RT-PCR.Results:There were significant differences in MBP transcription expressions between ODM group and ODM+1/2NNM group at the differentiation phase;MBP transcription expressions were higher in ODM+1/2NNM group than in ODM group on the 3rd day(P<0.05)and 5th day(P<0.05)of differentiation

while lower in ODM+1/2NNM group than in ODM group on the 7th day of differentiation(P <0.05). There were also significant differences in MBP transcription expressions between ODM +1 /2NNM group and ODM+1/2INM group at the differentiation phase;MBP transcription expressions were higher in ODM+1/2INM group than in ODM+1/2NNM group on the 3rd day of differentiation(P<0.05)

while lower in ODM+1/2INM group than in ODM+1/2NNM group on the 5th day(P<0.05)and 7th day(P<0.05)of differentiation. Conclusion:The neuronal microenvironment has significant effect on the differentiation of OPCs. The normal neuronal microenvironment can promote OPC differentiation

and the induced seizure-like discharge neuronal microenvironment can inhibit OPC differentiation.