Abstract: Background　Currently，acupuncture combined with traditional Chinese medicine（TCMherbs shows excellent outcomes in treating poststroke spasticity，but the mechanism remains unclear. Objective　To observe the effect of Shaoyao Gancao Decoction combined with electroacupuncture on the motor function and synaptic plasticity in the M1 cortex ofrats with poststroke spasticity. Methods　From November 2022 to June 2023，72 healthy male Sprague-Dawley（SDrats with 7 weeks old were included. Finally，60 rats were randomly divided into the blank group，model group，electroacupuncture group，baclofen group，TCM group，and electroacupuncture combined with TCM group，with 10 rats in each group. The intervention began from the first day after modeling and lasted for 6 days. Electroacupuncture was applied to the “Quchi”（GV20and “Yanglingquan”（GB34acupoints on the affected side，with a dense wave at the frequency of 100 Hz for 30 minutes daily. Daily gavage of Shaoyao Gancao Decoction at a dose of 4.2 g/kg，and 5.25 mg/kg baclofen were given in the corresponding groups. Catwalk gait analysis was tested before modeling and on the 1st，3rd and 6th day after modeling. The samples were taken on day 6， and nerve cells injury in the M1 cortex was tested by Nissl stain. The expression levels of brain-derived neurotrophic factor（BDNF）， γ-aminobutyric acid（GABA），and neurotrophin-3（NT3in M1 cortex were detected by fluorescence quantitative polymerase chain reaction（qPCR and Western blotting. Synaptic plasticity was scanned by transmission electron microscopy（TEM）. Results　Catwalk gait analysis showed a significantly higher average footprint intensity on day 3 in the model group than the blank group（P<0.05）. The percentage of four-feet stance on day 6 was significantly higher in the electroacupuncture combined with TCM group than the blank group（P<0.05）. Nissl staining showed similar neuronal damage between the electroacupuncture combined with TCM group and the blank group. QPCR showed a significantly higher mRNA level of BDNF and lower mRNA level of GABA in the electroacupuncture combined with TCM group than the blank group（P<0.05）. Western blotting showed significantly lower protein levels of GABA，NT3 and BDNF in the model group，electroacupuncture group and baclofen group than the blank group（P<0.05）. Their protein levels were significantly higher in the TCM group and electroacupuncture combined with TCM group than the model group（P<0.001）. TEM revealed relatively complete synaptic morphology，great number of vesicles，clear boundaries of the front and rear membranes，and long contact boundary，presenting a similar morphology to the blank group. Conclusion　Electroacupuncture combined with Shaoyao Gancao Decoction group is effective in treating poststroke spasticity in rats by improving synaptic plasticity.

Key words: Stroke, Electroacupuncture, Shaoyao Gancao Decoction, Synapses, Limb spasticity

摘要： 背景　目前针药结合治疗脑卒中后肢体痉挛疗效尚佳，但其机制不明。目的　观察电针联合芍药甘草汤对卒中后肢体痉挛大鼠运动功能及M1区突触重塑的影响。方法　2022年11月—2023年6月，选取健康雄性SD大鼠72只，7周龄，最终纳入60只。依据随机数字表法将大鼠分为空白组、模型组、电针组、巴氯芬组、中药组、针药组。于造模后第1天至第6天进行干预，电针组大鼠行电针患侧“曲池”“阳陵泉”，密波，100 Hz，30 min/次，1次/d。中药组予芍药甘草汤灌胃4.2 g/kg，1次/d。巴氯芬组以巴氯芬溶液灌胃，5.25 mg/kg，1次/d。针药结合组予电针联合中药灌胃，方法和剂量同上，1次/d。造模前及造模后第1、3、6天行catwalk步态分析。第6天采集数据后，取脑皮质M1区备用。尼氏染色观察M1区神经元损伤情况。荧光定量PCR技术、Western blotting法检测M1区脑源性神经营养因子（BDNF）、γ-氨基丁酸（GABA）、神经营养素3（NT3）含量。电镜观察M1区突触生长情况。结果　造模后第3天针药组大鼠足迹平均强度大于空白组，造模后第6天针药组大鼠四足支撑百分比高于空白组（P<0.05）。尼氏染色发现针药组与空白组的神经元损伤情况较为接近。荧光定量PCR结果显示，针药组大鼠GABA表达水平低于空白组，BDNF表达水平高于空白组（P<0.05）。Western blotting法结果显示，模型组、电针组、巴氯芬组大鼠GABA、NT3、BDNF相对蛋白含量低于空白组（P<0.05）；中药组、针药组大鼠GABA、NT3、BDNF相对蛋白含量高于模型组（P<0.001）。电镜发现针药组突触形态较为完整，囊泡量多，前后膜边界清晰，接触边界较长，与空白组相似度更高。结论　电针联合芍药甘草汤可以改善卒中后肢体痉挛大鼠的运动功能，其机制可能是通过改善突触可塑性。

关键词: 脑卒中, 电针, 芍药甘草汤, 突触, 肢体痉挛