ABSTRACT
Objective:To study the efficacy of low-intensity focused ultrasound (LIFU) on neuropathic pain (NP) in mice, and its effect on the activation of astrocytes and the expression of pro-inflammatory cytokines were discussed.Methods:Thirty-six male C57BL/6J mice were randomly divided into three groups: sham operation (Sham) group and chroinc constriction injury (CCI) model group and treatment (CCI+ LIFU) group, 12 mice in each group.NP model was established by CCI on the sciatic nerve. The group of CCI+ LIFU received LIFU treatment for the anterior cingulate cortex (ACC) on the 7th day after surgery, the mechanical withdrawal threshold (MWT) on the affected side of mice was measured at preoperation 3, 6, 12, 18, 24, and 27 days after operation, respectively, H&E staining was used to observe pathological morphological changes in the ACC region, the expression levels of ACC region AQP4 and GFAP protein were detected by Western Blot and immunofluorescence, and the expression levels of ACC region pro-inflammatory cytokines IL-1β and TNF-α were detected by enzyme-linked immunosorption assay.Results:Compared with Sham group, MWT in the CCI group decreased from the 3rd day until the 27th day after surgery( P<0.05); Compared with the CCI group, the MWT in the CCI+ LIFU group increased on the 24th day after surgery, and was significantly higher than that of the CCI group on the 24th and 27th day after surgery ( P<0.05); LIFU stimulation did not produce significant pathological changes in the ACC region; Western Blot and immunofluorescence showed that AQP4 and GFAP protein expression in the ACC region were upregulated ( P<0.05) after peripheral nerve injury, while AQP4 and GFAP protein expression was downregulated after LIFU treatment ( P<0.05); Enzyme-linked immunosorbents showed that the expression of pro-inflammatory cytokines IL-1β and TNF-α in the region of ACC was upregulated ( P<0.05) after peripheral nerve injury, while the expression of IL-1β and TNF-α was downregulated after LIFU treatment ( P<0.05). Conclusions:LIFU can effectively relieve mechanical pain sensitivity symptoms in mice induced by CCI, possibly by inhibiting activation of astrocytes and neuro-inflammatory responses.