中文摘要：

目的探讨不同浓度M胆碱能受体激动剂Oxotremorine—M（Oxo—M）对大鼠脊髓Ⅱ板层甘氨酸能神经元自发抑制性突触后电流（sIPSCs）和微小抑制性突触后电流（mIPSCs）的影响。方法健康雄性清洁级SD大鼠15只，周龄3～4周，体重160～180g，取L1-5，脊髓节段制备脊髓薄片，采用全细胞膜片钳技术，依次持续灌注终浓度为1、3、5、10μmol／L Oxo—M，分别记录不同浓度Oxo-M作用前后脊髓Ⅱ板层甘氨酸能神经元sIPSCs和mIPSCs的频率及幅度。结果3—10μmol／L Oxo-M可增加脊髓Ⅱ板层甘氨酸能神经元sIPSCs频率，其中3μmol／L Oxo-M作用最明显，但3～10μmol／L Oxo—M对sIPSCs幅度无影响。2μmol／L甘氨酸受体特异性阻断剂士可宁可完全阻断记录到的sIPSCs，2μmol／L阿托品可完全阻断Oxo-M增加sIPSCs频率的效应。1～10μmol／L Oxo—M对mIPSCs的频率及幅度均无影响。结论Oxo-M可通过激活大鼠脊髓Ⅱ板层甘氨酸能神经元胞体上的M胆碱能受体增加甘氨酸能神经元递质的释放，但不呈剂量依赖性。

英文摘要：

Objective To investigate the effect of the musearinic aeetylcholine receptor （mAChR） agonist Oxo-trernorine-M （Oxo-M） on glycinergic spontaneous inhibitory postsynaptic currents （sIPSCs） and microinhibitory postsynaptie currents （mIPSCs） in lamina Ⅱ neurons in the spinal cord of rats. Methods Glycinergie IPSCs （sIPSCs and mIPSCs） in lamina Ⅱ neurons of spinal slices were recorded using the whole-cell voltage-clamp method. The non-selective mAehR agonist Oxo-M was applied through bath perfusion. The effects of Oxo-M 1, 3, 5 and 10μmol/L on sIPSCs and mIPSCs were examined. Results Oxo-M at the concentrations of 3-10 μmol/L significantly increased the frequency of sIPSCs without changing the amplitude in 16 lamina Ⅱ neurons tested. Interestingly, when the concentration of Oxo-M was increased to 10 μmol/L, the potentiating effect of Oxo-M on the frequency of slPSCs was decreased as compared with 3 μmol/L Oxo-M in the above 16 neurons. The sIPSCs were completely abolished by 2 μmol/L stryehnine. Atropine, the specific mAChR antagonist, completely blocked the effect of Oxo-M on the frequency of sIPSCs. In 9 additional lamina Ⅱ neurons, 1-10μmol/L oxo-M failed to alter significantly the frequency and amplitude of glycinergic mIPSCs. Conclusion Activation of mAChRs in the somatodendritic site of glycinerglc interneurons increases the synaptic glycine input to spinal dorsal horn neurons,but not in a dose-dependent manner.