Modulation of biphasic pattern of cortical reorganization in spinal cord transected rats by external magnetic fields

Magnetic field induces electric field in the brain and has the potential to modulate cortical plasticity giving rise to sustained excitability as well as behavioral modifications. The present study demonstrates the effect of extremely low frequency magnetic field (ELF-MF) on cortical reorganization after SCI in complete transection rat model. The spinal cord of male albino Wistar rats was completed transected at T-13 spinal level and ELF-MF (50 Hz, 17.96 µT) exposure given either for 5 or 12 or 32 days for temporal observations. A significant functional recovery was evident in locomotor, sensorimotor and motor behavioral tests after 32 days of magnetic field exposure. This was associated with an amelioration in cortical electrical activity, decrease in the lesion area and volume and modulation of plasticity associated proteins like Nogo-A and BDNF in a biphasic pattern. The results suggest improvement of functional, electrical and morphological parameters along with upregulation of plasticity associated proteins in an in-vivo SCI rat model following ELF-MF exposure for 32 days but not after 5, 12 days exposure