Oscillating field stimulation promotes spinal cord remyelination by inducing differentiation of oligodendrocyte precursor cells after spinal cord injury

Demyelination is part of the cascading secondary injury after the primary insult and contributes to the loss of function after spinal cord injury (SCI). Oligodendrocyte precursor cells (OPCs) are the main remyelinating cells in the central nervous system (CNS). We explored whether oscillating field stimulation (OFS) could efficiently promote OPC differentiation and improve remyelination after SCI. SD rats with SCI induced by the Allen method were randomly divided into two groups, the SCI+OFS group and SCI group. The former group received active stimulator units and the latter group received sham (inoperative) stimulator units. Additionally, rats that only received laminectomy were referred as the sham group. The electric field intensity was 600 V/mm, and the polarity was alternated every 15 minutes. The results showed that the SCI+OFS rats had significantly less demyelination and better locomotor function recovery after 12-weeks treatment. The OFS treatment significantly increased the number of Gal C-positive OPCs after 2-weeks treatment. Furthermore, these rats had higher protein expression of oligodendroglial transcription factors Olig2 and NKx2.2. These findings suggest OFS can promote locomotor recovery and remyelination in SCI rats and this effect may be related to the improved differentiation of OPCs in the spinal cord.