Stimulation of regeneration of the rat sciatic nerve by 50 Hz sinusoidal magnetic fields.

The effect of sinusoidal magnetic field stimulation on regeneration of the rat sciatic nerve was studied. Rats were exposed, after crush lesioning of the nerve, between a pair of Helmholtz coils to a 50 Hz magnetic field of 0.2 mT or 0.4 mT, respectively. Regeneration of the sciatic nerve was measured by the "pinch test," or by immunocytochemical staining for neurofilaments 1 to 6 days after the crush lesion. Intermittent stimulation (4 h/day) at 0.2 mT did not affect regeneration, while continuous stimulation with the same field enhanced regeneration distances measured at Days 1, 2, and 3. Intermittent stimulation with 0.4 mT increased regeneration distances in 3-day regenerated nerves. In the rats exposed continuously to 0.4 mT regeneration was higher in all groups (1, 2, 3, 4, and 6 days). This field enhanced the regeneration velocity by 21%. Pretreatment for 7 days with continuous stimulation either at 0.2 mT or at 0.4 mT did not affect regeneration of the sciatic nerve after a crush lesion.