Electroacupuncture remodels brain functional connectivity and improves bone metabolism in ovariectomized rats

Electroacupuncture has demonstrated established efficacy in treating postmenopausal osteoporosis, yet the central mechanisms underlying its action via the brain-bone axis remain incompletely understood. This study employed multimodal resting-state functional magnetic resonance imaging to investigate neurofunctional changes induced by electroacupuncture in a rat model of postmenopausal osteoporosis. Twenty-four female Sprague-Dawley rats were randomly allocated to electroacupuncture, sham, and model (ovariectomized) groups. The electroacupuncture group received an 8-week intervention at acupoints GB30, GB34, and GB39. We assessed brain function through amplitude of low-frequency fluctuation, regional homogeneity, and region-of-interest functional connectivity, while simultaneously measuring serum bone turnover markers via enzyme-linked immunosorbent assay. Our results demonstrated that electroacupuncture significantly improved bone microstructure and reduced bone resorption marker levels. Neuroimaging revealed enhanced cerebellar neural activity which correlated negatively with bone resorption, alongside decreased neural synchronization in the entorhinal cortex. Furthermore, strengthened functional connectivity between entorhinal and visual cortices positively correlated with bone formation markers, while weakened somatosensory-cerebellar connectivity correlated with reduced bone resorption. Bayesian mediation analysis provided strong statistical evidence for the role of the entorhinal-visual pathway involvement in bone formation regulation and cerebellar mediation of bone resorption suppression. These findings systematically reveal the association between electroacupuncture-induced brain functional reorganization and bone metabolic improvements, offering new insights into the role of the brain-bone axis in osteoporosis management.