Repetitive transcranial magnetic stimulation suppresses glia-associated neuroinflammation and promotes peripheral nerve recovery in neuropathic pain

BackgroundNeuropathic pain (NP) is a chronic condition caused by peripheral nerve damage and is characterized by persistent neuroinflammation and limited treatment options. Repetitive transcranial magnetic stimulation (rTMS) has been reported to modulate neuroinflammation in the brain.

However, it remains unclear whether rTMS also influences inflammatory responses in the spinal cord and peripheral nerve structures.MethodsA rat NP model was established by unilateral sciatic nerve ligation, and the effects of rTMS were evaluated through behavioral testing and molecular, histological, and ultrastructural analyses of the spinal cord and sciatic nerve.ResultsNP induced thermal hyperalgesia and mechanical allodynia, whereas rTMS significantly alleviated these pain-related behaviors (p < 0.05). In the spinal cord, NP increased the expression of pro-inflammatory markers including CD40, CD86, ionized calcium-binding adapter molecule-1 (Iba-1), and transient receptor potential cation channel subfamily V member 1 (TRPV1) (p < 0.05 for TRPV1; p < 0.01 for the others).

rTMS significantly attenuated the increases in CD86, Iba-1, and TRPV1 (p < 0.01 for Iba-1; p < 0.05 for the others), while CD40 showed a decreasing trend without statistical significance.