Pulsed magnetic fields enhance the rate of recovery of damaged nerve excitability

Abstract

Pulsed magnetic fields (PMFs) have well-known beneficial effects on nerve regeneration. However, little research has examined the nerve conduction characteristics of regenerating peripheral nerves under PMF. The main goal of this study was to examine the conduction characteristics of regenerating peripheral nerves under PMFs. The sucrose-gap recording technique was used to examine the conduction properties of injured sciatic nerves of rats exposed to PMF. Following the injury, peripheral nerves were very sensitive to repetitive stimulation. When the stimulation frequency was increased, the amplitude of the compound action potential (CAP) decreased more at 15 days post-crush injury (dpc) than at 38 dpc. PMF treatment for 38 days after injury caused significant differences in the conduction of CAPs. Moreover, application of PMF ameliorated the abnormal electrophysiological activities of nerves such as hyperpolarizing afterpotentials and delayed depolarizations that were revealed by 4-aminopyridine (4-AP). Consequently, characteristic findings in impulse conduction of recovered nerves under PMF indicate that the observed abnormalities in signaling or aberrant ion channel functions following injury may be restored by PMF application.

Neural circuit repair by low-intensity magnetic stimulation requires cellular magnetoreceptors and specific stimulation patterns

“…These are restricted in high-intensity rTMS for technical reasons (heating) and safety considerations [pain and seizures; ( 2 )]. In contrast, low-field stimulation uses a wide range of frequencies and patterns to modulate neuronal excitability ( 3 , 5 ), neuroplasticity ( 6 ), neuron survival ( 7 , 8 ), and calcium signaling ( 9 ). Nevertheless, it is unknown how these weak fields induce their diverse physiological effects.…”

The change of HCN1/HCN2 mRNA expression in peripheral nerve after chronic constriction injury induced neuropathy followed by pulsed electromagnetic field therapy

“…Pulsed magnetic field (PMF) has been used to treat the peripheral nerve injury for years, for it can accelerate the functional recovery of injured peripheral nerve [25]. PMF can ameliorate the hyperpolarization of after potentials and delayed depolarization of nerves [26]. PMF can also promote peripheral nerve regeneration in different experimental animal models [27; 28], because axons of neuron are sensitive to electrical and magnetic stimulation [24].…”

Does Pulsed Magnetic Field Therapy Influence Nerve Regeneration in the Median Nerve Model of the Rat?

“…Gunay and Mert assessed the influence of conduction characteristics of a regenerating peripheral nerve in a sciatic crush lesion model in the rat over a 15- and 38-day period. Here, abnormalities in signaling and aberrant ion channel functions were time-dependently restored by the pulsed magnetic field therapy [27]. Another in vitro study could show that neurite growth was influenced by the direction of the magnetic field applied by nanoparticles [28, 29].…”