摘要
本研究经颧骨下缘入路建立大鼠三叉神经痛模型,运用全细胞膜片钳的方法观察大鼠三叉神经节神经元中电压门控性钾电流的变化。30只雄性Sprague-Dawley大鼠分为手术组与假手术组,通过颧骨下缘入路慢性压迫眶下神经方法,建立三叉神经痛模型。在分离培养的三叉神经节神经元上,通过全细胞膜片钳方法记录延迟外向钾电流(delayed rectifier po-tassium current,IK)和瞬时外向钾电流(transient outward potassium current,IA)的变化。手术组大鼠术侧触须垫机械痛阈在术后第6天开始明显降低,持续到第21天,于第15天为最低;手术组非术侧痛阈亦有降低;而假手术组痛阈在术后无明显改变。与假手术组相比,手术组分离培养的三叉神经节细胞IK明显减小,术侧和非术侧IA均明显降低。本实验证明了经颧骨下缘入路压迫眶下神经建立大鼠慢性三叉神经痛模型方法简便可行。此模型大鼠三叉神经节中分离培养的神经元上IA和IK明显降低,提示在三叉神经痛的形成过程中,电压门控性钾通道可能参与介导了外周机械痛阈的降低,进而与外周痛觉过敏有关。
The purpose of this study was to establish a model of trigeminal neuralgia （TN） through an approach from lower edge of cheekbone and to observe the functional changes in the voltage-gated potassium currents in the cultured trigeminal ganglion （TG） neurons. Thirty Sprague-Dawley male rats were divided into two groups, the sham-operated （sham） group and the operated group. The TN model was carried out by using a chronic constriction injury of the infraorbital nerve （ION-CCI） from lower edge of cheekbone. Peripheral pain threshold test and whole-cell patch clamp recording were used to determine the difference between sham and ION-CCI rats. The withdrawal threshold of whisker pad in operated side of ION-CCI rat was decreased significantly from 6 d after operation and then maintained until 21 d, with the lowest on the 15th day. The threshold of whisker pad in non-operated side of operated rats was also decreased significantly compared with that in the sham group. Delayed rectifier potassium current （I_K） in cultured ION-CCI TG neurons was decreased significantly compared with that in the sham group. Transient outward potassium currents （I_A） in both operated and nonoperated sides of TG neurons from ION-CCI rats were also reduced significantly compared with that in the sham group. The present study provided a new method of ION-CCI. In this model, the decrease of I_A and I_K might contribute, at least in part, to the decrease in mechanical pain threshold of whisker pad and the subsequent hyperalgia.
出处
《生理学报》
CAS
CSCD
北大核心
2009年第1期72-78,共7页
Acta Physiologica Sinica
基金
supported by the Key Program of Shanghai Science and Technology Committee (No. 08JC1405400)
关键词
三叉神经痛
钾通道
电压门控
三叉神经节
膜片钳
trigeminal neuralgia
potassium channels, voltage-gated
trigeminal ganglion
patch-clamp techniques
