Electroacupuncture alleviates pain in rats with Cervical Spondylotic Radiculopathy by promoting M2 polarization of spinal macrophages through suppression of Piezo1 protein expression.

Researchers investigated whether electroacupuncture could relieve nerve pain caused by cervical spondylotic radiculopathy (CSR), a condition where compressed nerves in the neck create pain and movement problems. Using a rat model, scientists created CSR by inserting material into the spinal canal to compress nerve roots, then treated some animals with electroacupuncture at specific points (LI4 and LR3) for 20 minutes daily over seven days.

The study found that electroacupuncture significantly improved both movement difficulties and pain sensitivity in rats with CSR. The researchers discovered that this pain relief occurred through a specific biological mechanism: electroacupuncture reduced the expression of a protein called Piezo1 in the spinal cord, which in turn changed how immune cells called macrophages behaved. Specifically, the treatment shifted macrophages from an inflammatory state (M1) that promotes pain to an anti-inflammatory state (M2) that reduces pain and supports healing.

To confirm this mechanism, researchers gave some rats a chemical called Yoda1 that activates Piezo1. When Piezo1 was artificially activated, it reversed the beneficial effects of electroacupuncture, proving that suppressing this protein was essential for pain relief.

For patients suffering from cervical radiculopathy, this research provides scientific evidence that electroacupuncture may offer real pain relief by changing how the body's immune system responds to nerve injury. The study suggests electroacupuncture doesn't just mask symptoms but actually modulates inflammation at the cellular level. If you're considering electroacupuncture for neck-related nerve pain, consult with a licensed acupuncturist who has experience treating neurological conditions.

This study investigated electroacupuncture's mechanism in alleviating cervical spondylotic radiculopathy (CSR) pain through a rat model with surgically induced nerve root compression. Following successful modeling confirmed by gait scoring and thermal threshold testing on day 6, rats received 20-minute EA treatments at bilateral LI4 and LR3 daily for seven days starting day 7. Behavioral assessments, histopathology, immunofluorescence, Western blot, and ELISA were employed.

EA significantly improved motor function and thermal pain thresholds while suppressing spinal Piezo1 expression and M1 markers (CD86, iNOS, IL-6, NF-κB, p-NF-κB) and upregulating M2 markers (CD206, Arg1, TGF-β, IL-10). Administration of Piezo1 agonist Yoda1 (1.5 mg/kg IP) reversed EA's therapeutic effects, confirming Piezo1's mechanistic role. The study demonstrates that EA alleviates CSR neuropathic pain by downregulating the mechanosensitive channel Piezo1, thereby promoting anti-inflammatory M2 macrophage polarization over pro-inflammatory M1 phenotype in spinal tissue. This provides evidence for EA's immunomodulatory mechanism in treating radicular pain conditions.