精准医学杂志 (Jun 2023)

ANALGESIC EFFECT OF TRANSCRANIAL DIRECT CURRENT STIMULATION ON CHRONIC PAIN IN A RAT MODEL OF OSTEOARTHRITIS AND ITS MECHANISM

  • YE Yinshuang, XU Jiawei, WANG Lin, LI Tieshan

DOI
https://doi.org/10.13362/j.jpmed.202303017
Journal volume & issue
Vol. 38, no. 3
pp. 264 – 267

Abstract

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Objective To investigate the analgesic effect of transcranial direct current stimulation (tDCS) on chronic pain in a rat model of monosodium iodoacetate (MIA)-induced osteoarthritis (OA) and its mechanism. Methods Healthy male Sprague-Dawley rats were randomly divided into sham-operation group, MIA group, tDCS group, and sham-tDCS group, with 9 rats in each group. The rats in the sham-operation group were given intra-articular injection of normal saline into the left knee joint, and those in the MIA group, the tDCS group, and the sham-tDCS group were given MIA injection at the same site to establish a model of chronic pain in OA. On day 21 after MIA injection, the rats in the tDCS group and the sham-tDCS group were treated with real or sham tDCS, respectively, for 8 d. The pain behavioral test was performed for the rats in each group on day 1, 2, and 7 after treatment; the periaqueductal gray (PAG) of rats were collected on day 2 after treatment and Western blot was used to measure the expression of brain-derived neurotrophic factor (BDNF). Results The pain behavioral test showed that compared with the sham-tDCS group, the tDCS group had a significantly longer thermal paw withdrawal latency at each time point after treatment (F=11.25-21.48,P<0.01) and a significantly higher mechanical paw withdrawal threshold at each time point after treatment (F=54.42-186.40,P<0.01). Western blot showed that compared with the sham-tDCS group, the tDCS group had a significant reduction in the protein expression of BDNF in PAG tissue (F=24.70,P<0.01). Conclusion This study shows that tDCS can effectively alleviate chronic pain in rats with MIA-induced OA, and such therapeutic effect can last till day 7 after treatment; tDCS exerts an analgesic effect possibly by downregulating the expression of BDNF and reducing neuronal excitability in PAG tissue of rats with MIA-induced OA.

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