05/08/2026
Acupuncture neuromodulation begins at the site of needle insertion, where mechanical stimulation of acupoints directly activates primary afferent nerve fibers. These include myelinated Aβ and Aδ fibers as well as unmyelinated C fibers, with the specific fiber types recruited depending on the modality and intensity of stimulation. Electroacupuncture (EA) preferentially activates A fibers at intensities sufficient to produce analgesia, while manual acupuncture (MA) activates both A and C fibers depending on the depth and tissue layer stimulated. 
Functional neuroimaging studies consistently demonstrate that acupuncture modulates activity across a distributed set of brain regions, including the somatosensory cortices, limbic system (amygdala, hippocampus, cingulate cortex), thalamus, hypothalamus, basal ganglia, brainstem nuclei (periaqueductal gray [PAG], nucleus raphe magnus [NRM]), and cerebellum.
Acupuncture also promotes peripheral nerve regeneration through retrograde transport of neurotrophic factors such as NGF, BDNF, and GDNF.
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Fan Z, Dou B, Wang J, Wu Y, Du S, Li J, Yao K, Li Y, Wang S, Gong Y, Guo Y, Xu Z. Effects and mechanisms of acupuncture analgesia mediated by afferent nerves in acupoint microenvironments. Front Neurosci. 2024 Feb 7;17:1239839. doi: 10.3389/fnins.2023.1239839. PMID: 38384495; PMCID: PMC10879281.
Yang Y, Rao C, Yin T, Wang S, Shi H, Yan X, Zhang L, Meng X, Gu W, Du Y, Hong F. Application and underlying mechanism of acupuncture for the nerve repair after peripheral nerve injury: remodeling of nerve system. Front Cell Neurosci. 2023 Oct 24;17:1253438. doi: 10.3389/fncel.2023.1253438. PMID: 37941605; PMCID: PMC10627933.
