Electrical stimulation enhances peripheral nerve regeneration after crush injury in rats

Injured peripheral nerves have the ability to regenerate; however, there is conflicting evidence with regard to whether electrical stimulation (ES) accelerates or hinders neural regeneration. To study the effect of ES on peripheral nerve regeneration following nerve crush injury, 54 Wistar rats were randomly divided into three groups (n=18/group); the control, crush and crush + ES group. Four weeks after surgery, the sciatic functional index (SFI), compound muscle action potential (CMAP) conduction velocity and amplitude in the regenerated nerve, nerve histomorphometry, and levels of myelin protein zero (PO) mRNA and protein at the crush site were assessed. The rats exposed to crush + ES had a significantly increased CMAP conduction velocity, enhanced myelin sheath thickness and increased PO mRNA and protein levels compared with the rats exposed to crush alone. However, the CMAP amplitude and axonal diameter were similar in the crush and crush + ES rats. Findings of this study demonstrated that the application of ES (3 V, 0.1 ms, 20 Hz, 1 h) immediately after nerve injury accelerates remyelination and may provide a therapeutic clinical strategy.