Electroacupuncture Relieves Fibromyalgia Pain in a Female Mouse Model by Augmenting Cannabinoid Receptor 1 Expression and Suppressing Astrocyte and Microglial Activation in Nociceptive Pathways.

Fibromyalgia causes widespread chronic pain that's difficult to treat, affecting millions of people, predominantly women. Researchers used a female mouse model to investigate whether electroacupuncture could relieve fibromyalgia pain and how it works in the body. The study created fibromyalgia-like symptoms in mice using intermittent cold stress, which caused increased sensitivity to both touch and heat—similar to what human fibromyalgia patients experience.

The researchers found that electroacupuncture effectively reduced both types of pain sensitivity. They discovered it works by increasing the expression of cannabinoid receptor 1 (CB1) in multiple pain-processing areas of the nervous system, including the spinal cord and brain regions. CB1 receptors naturally occur in the body and help regulate pain signals by calming overactive nerve cells.

The study also showed that electroacupuncture reduced inflammation in the nervous system by calming overactive immune cells called microglia and astrocytes, which contribute to chronic pain when activated. When researchers blocked CB1 receptors, electroacupuncture lost its pain-relieving effects, confirming that activating these receptors is essential for the treatment to work. Conversely, injecting a CB1-activating substance at acupuncture points partially reproduced the pain relief.

These findings suggest electroacupuncture may offer a promising treatment option for fibromyalgia by naturally activating the body's own pain-control systems through the cannabinoid pathway. This is particularly relevant as fibromyalgia remains challenging to treat with conventional medications. If you're considering acupuncture for fibromyalgia, consult with a licensed acupuncturist experienced in treating chronic pain conditions.

This study investigated electroacupuncture's mechanism of action in a female mouse fibromyalgia model induced by intermittent cold stress (ICS). Mice exhibited mechanical allodynia (von Frey test) and thermal hyperalgesia (Hargreaves test). Electroacupuncture significantly attenuated both pain modalities while upregulating cannabinoid receptor 1 (CB1) expression in dorsal root ganglia, spinal cord, hypothalamus, and periaqueductal gray matter. EA treatment suppressed reactive gliosis (microglia and astrocyte activation) and downregulated the TLR4-MyD88-TRAF6 inflammatory signaling pathway. Trpv1 gene deletion mitigated ICS effects, implicating TRPV1 in fibromyalgia pathophysiology. Critically, acupoint injection of CB1 agonists partially replicated EA's antinociceptive effects, while CB1 antagonists abolished them, establishing CB1 activation as necessary for therapeutic efficacy. Clinical implications suggest electroacupuncture modulates endogenous cannabinoid systems and neuroinflammation in central and peripheral nociceptive pathways, offering a mechanism-based rationale for fibromyalgia treatment. The female-specific model enhances translational relevance given fibromyalgia's sex predilection.