[Effect of electroacupuncture on microglial polarization and activity of α7nAChR-TLR4/MyD88/NF-κB signaling pathway in the anterior cingulate cortex of rats with chronic inflammatory pain-depression comorbidity].

Researchers studied whether electroacupuncture could help rats experiencing both chronic pain and depression together, a common condition in humans. They created inflammation-induced pain in rats and then treated some with electroacupuncture at specific points (similar to LI4 and LR3 in humans) for 20 minutes daily over two weeks. The study examined changes in a brain region called the anterior cingulate cortex, which processes both pain and emotions. The results showed that electroacupuncture significantly reduced pain sensitivity and improved depression-like behaviors compared to untreated rats. Testing revealed the treated rats showed more interest in sweet water, moved around more freely, and gave up less quickly when challenged—all signs of improved mood. The researchers found that electroacupuncture worked by changing how immune cells in the brain (called microglia) behaved, shifting them from an inflammatory state to a healing state. It also reduced inflammatory chemicals like TNF-α and increased anti-inflammatory substances. Brain tissue examination showed less nerve cell damage in treated rats. This study suggests electroacupuncture may help people suffering from both chronic pain and depression by reducing brain inflammation and protecting nerve cells through specific biological pathways. If you're considering acupuncture for chronic pain with depression, consult a licensed acupuncturist experienced in treating these combined conditions.

This rat study (n=36) investigated electroacupuncture's effects on chronic inflammatory pain-depression comorbidity via the α7nAChR-TLR4/MyD88/NF-κB pathway in the anterior cingulate cortex. Complete Freund's adjuvant induced the condition; bilateral LI4 and LR3 received EA (1.5 Hz, 1 mA, 20 min daily × 14 days) starting day 14 post-modeling. EA significantly improved mechanical withdrawal threshold, thermal latency, sucrose preference, open field activity, and forced swim test performance (all P<0.05). Mechanistically, EA upregulated α7nAChR expression, promoted M2 microglial polarization (increased CD206/Iba-1, IL-4, IL-10), suppressed M1 polarization (decreased CD86/Iba-1), reduced pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and downregulated TLR4/MyD88/NF-κB signaling pathway activation. Histopathology showed reduced neuronal damage. Clinical relevance: EA demonstrates dual analgesic-antidepressant effects through cholinergic anti-inflammatory pathway modulation and microglial phenotype shifting, supporting its use for comorbid pain-depression presentations.