Brainstem circuit may explain how acupuncture helps stroke patients swallow

A mouse study suggests electroacupuncture at the neck acupoint Lianquan (CV23) can improve swallowing after stroke by acting through the hypoglossal nucleus, a brainstem motor center tied to tongue movement. The findings, published Aug. 25, 2025 in Acupuncture Research, could help explain a treatment already used for post-stroke dysphagia and point to new rehabilitation targets.

Why it matters: - Post-stroke dysphagia affects nearly half of stroke patients and can lead to malnutrition, pneumonia or death. - The study offers a biological explanation for why electroacupuncture at Lianquan (CV23) is used in swallowing rehabilitation. - The work points to the hypoglossal nucleus (12N) as a possible target for future swallowing therapies.

What happened: - Researchers from Guangzhou University of Chinese Medicine studied electroacupuncture at Lianquan (CV23) in a mouse model of post-stroke dysphagia. - The study was published in Acupuncture Research on Aug. 25, 2025. - The team used viral tracing, chemogenetic inhibition and laryngoscopy to map the circuit behind the treatment effect. - The researchers also examined upstream brain regions that project to 12N.

The details: - Lianquan (CV23) sits on the anterior midline of the neck above the hyoid bone, in a region closely tied to tongue movement and swallowing. - The hypoglossal nucleus sends direct, monosynaptic projections to tissues around Lianquan (CV23). - In stroke mice, one 15-minute electroacupuncture session at Lianquan (CV23) improved vocal cord movement cycles. - The same treatment increased swallowing-related muscle electrical activity, measured by electromyography. - The stimulation parameters were 2 Hz and 1 mA. - When researchers silenced the hypoglossal nucleus in healthy mice, swallowing muscle activity dropped. - In stroke mice, silencing the hypoglossal nucleus reduced the benefit of electroacupuncture. - Vocal cord movement slowed when 12N was inhibited, and muscle activity fell back toward impaired levels. - Retrograde tracing identified several upstream inputs to 12N, including the nucleus tractus solitarii, intermediate reticular nucleus, spinal trigeminal nucleus caudalis and lateral paragigantocellular nucleus. - The nucleus tractus solitarii is a core part of the brainstem swallowing central pattern generator. - The study describes 12N as an output gate for electroacupuncture’s effect on post-stroke dysphagia. - The research was funded by the General Program of the National Natural Science Foundation of China, grant numbers 82374573 and 82474623. - The article lists DOI 10.13702/j.1000-0607.20250444 as the source identifier.

Between the lines: - The results suggest Lianquan (CV23) may work through a defined brainstem motor pathway rather than through a vague local reflex. - The findings also narrow the focus for swallowing rehab research toward hypoglossal nucleus–based neuromodulation. - Hypoglossal nerve stimulation is already used for obstructive sleep apnea, but not yet established for swallowing disorders. - The study strengthens the case for testing whether central swallowing circuits can be targeted more precisely in post-stroke care.

What's next: - The researchers want to understand how the needle signal travels back up to the brain. - Future work may test hypoglossal nerve–based neuromodulation for swallowing rehabilitation. - Further studies will likely examine the upstream brainstem inputs to 12N, including the nucleus tractus solitarii and intermediate reticular nucleus.

The bottom line: - A single acupoint, Lianquan (CV23), may improve swallowing after stroke by engaging a specific brainstem motor circuit centered on the hypoglossal nucleus.