Electroacupuncture eases pain and anxiety by rebalancing a brain circuit, mouse study finds

A mouse study published Aug. 25, 2025, in Acupuncture Research says electroacupuncture reduced neuropathic pain and anxiety by activating a serotonin-based circuit linking the dorsal raphe nucleus and the basolateral amygdala. The findings point to a possible non-drug approach for treating both the physical and emotional burden of chronic nerve pain.

Why it matters: - Neuropathic pain affects nearly 10% of the global population. - Up to 60% of people with neuropathic pain also experience anxiety or other mood disorders. - Anxiety can intensify pain perception and make treatment harder. - The study suggests electroacupuncture may address pain and anxiety together instead of treating them as separate problems. - The findings could help refine non-drug therapies for chronic nerve pain and its psychiatric effects.

What happened: - Researchers from Zhejiang Chinese Medical University, affiliated hospitals, and Hangzhou Red Cross Hospital in China published a mouse study on Aug. 25, 2025, in Acupuncture Research. - The team used a partial leg nerve injury model to trigger neuropathic pain and anxiety-like behavior. - The researchers applied electroacupuncture at Zusanli (ST36) and Sanyinjiao (SP6) for 30 minutes per session, six sessions total. - The stimulation parameters were 100 Hz and 0.3 mA. - The team used viral tracing, chemogenetics, and fiber photometry to track and manipulate brain activity. - The study identified a direct circuit between the dorsal raphe nucleus (DRN) and the basolateral amygdala (BLA) that uses serotonin (5-HT) as its messenger.

The details: - In injured mice, DRN 5-HT neurons became abnormally quiet. - The same mice showed higher pain sensitivity and anxiety-like behavior, including avoiding open areas in elevated maze tests. - After six electroacupuncture sessions, pain thresholds increased significantly. - Anxiety-like behavior also declined after treatment. - Calcium imaging showed reduced activity in the DRN 5-HT-BLA circuit after injury. - Immunofluorescence analysis showed increased c-Fos expression in DRN 5-HT neurons after electroacupuncture. - The treatment also increased the proportion of c-Fos-positive CaMK II neurons in the BLA. - When researchers chemogenetically inhibited the DRN 5-HT-BLA circuit, electroacupuncture no longer relieved pain or anxiety. - The circuit suppression did not change general movement or exploratory drive. - The study says the effect was specific to the targeted circuit rather than a broad boost in activity. - The DOI is 10.13702/j.1000-0607.20250181. - The original source URL is the full paper. - The work received funding from the General Program of the National Natural Science Foundation of China, Grant No. 82074541.

Between the lines: - The key result is not just that electroacupuncture reduced symptoms, but that blocking one circuit erased the benefit. - That makes the DRN-5-HT-BLA pathway look like a required mechanism, not a side effect. - The study also gives traditional acupuncture a modern neuroscience explanation focused on emotion and sensation together. - The findings are in mice, so human benefit still needs confirmation.

What's next: - Future studies may test whether other brain circuits also interact with the DRN-5-HT-BLA pathway. - Researchers may use the circuit-level data to fine-tune stimulation settings and acupoint selection. - The results could guide follow-up work on electroacupuncture as a non-drug option for neuropathic pain with anxiety.