Regulatory mechanism of acupuncture on neural oscillations in chronic pain patients
Chronic pain remains a major health challenge because persistent nociceptive input, central sensitization, neuroimmune activation, and affective-cognitive dysregulation jointly reshape brain networks. Neural oscillations provide a temporally precise window into these processes: gamma-band activity is often linked to nociceptive salience and cortical hyperexcitability, whereas alpha and theta rhythms are associated with sensory gating, descending control, attention, and emotional regulation. This narrative review synthesizes evidence on how acupuncture may regulate oscillatory activity in chronic pain through peripheral mechanotransduction, spinal and supraspinal network modulation, neurotransmitter balance, neuroimmune signaling, and plasticity-related molecular pathways. We also evaluate clinical neuroimaging evidence from EEG, MEG, fMRI, fNIRS, and multimodal studies, with attention to acupoint selection, stimulation parameters, sham design, pain phenotype, cross-frequency coupling (CFC), and analytical pipelines. Current evidence supports acupuncture as a multi-level neuromodulatory intervention that may normalize abnormal pain-related oscillations and improve functional connectivity among the anterior cingulate cortex, insula, thalamus, prefrontal cortex, and default-mode/limbic networks. However, many mechanistic claims remain indirect, and future studies should combine standardized acupuncture dosing, prespecified oscillatory biomarkers, longitudinal clinical outcomes, and multimodal neurophysiology. By reframing acupuncture from an empirical analgesic intervention to a candidate biomarker-guided neuromodulation strategy, this review highlights a translational route for integrating traditional medicine, neuroscience, and bioengineering in chronic pain management.