DRG慢性痛信号产生的细胞兴奋性分型及离子通道机制  

The classification of excitability and its ion channel mechanism in DRG neurons underlying chronic pain signal

作　　者：解柔刚[1] 段建红[1] 王文挺[1] 刘一辉[1] 邢俊玲[1] 胡三觉[1] 

机构地区：[1]第四军医大学神经生物学教研室,西安710032

出　　处：《神经解剖学杂志》2010年第3期261-267,共7页Chinese Journal of Neuroanatomy

基　　金：国家自然科学基金重点项目(305302600);国家自然科学基金面上项目(30870829)

摘　　要：目的:研究Hodgkin提出的兴奋性分型是否存在于背根神经节(Dorsal Root Ganglion,DRG),并对该分型及介导该分型的离子通道电流的变化在慢性痛信号产生中的重要作用进行探讨。方法:本研究通过制备背根节慢性压迫模型(chronic compression of DRG,CCD),在整节消化后的DRG大中细胞进行全细胞膜片钳记录。结果:依照神经元受刺激后产生动作电位的特征,79只大鼠的311例神经元可分为三种类型。在正常对照组(n=179),1、2、3型神经元所占比例分别为13%、27%和60%;在CCD组(n=134)比例则分别为27%、33%和40%。统计分析显示慢性压迫损伤后,1型神经元分型比例明显增加,而3型神经元分型比例显著减少(P<0.05)。正常DRG神经元中,持续钠电流(INaP)的幅值在1、2型神经元中比3型神经元明显要高(P<0.05)。CCD术后INaP在1、2型神经元中均增加,但仅在1型神经元有显著性差异(P<0.05)。结论:DRG大中细胞在慢性压迫损伤后,神经元兴奋性分型中1、2型神经元的比例增多和1、2型神经元上INaP电流的增加,共同造成了由DRG向更高级中枢的信息传递的加强。Objective： To demonstrate the exist of neuronal excitability proposed by Hodgkin and explore the possible role of its ratio change as well as the ion channel mechanism after the CCD model. Methods： Chronically compressed dorsal root ganglion （DRG） model was established. After digestion, the DRG preparation was used for whole-cell patch clamp. Results： According to neuron＇s property responding to the current injection, 311 DRG large neurons of 79 rats were classified into 3 classes. In neurons （n = 179）from normal rats, the ratio was 13%, 27% and 60% respectively for class 1,2 and 3 neurons, while in CCD group（ n = 134） the ratios of class 1,2 and 3 neurons were 27% , 33% and 40% correspondingly. Comparing to normal group, a dramatic increase of class 1 and decrease of class 3 were observed in CCD group （ P 〈 0.05 ）. In normal group, the persistent sodium current （ INaP ） were recorded to have larger amplitude on the class 1 and class 2 than those of class 3 （P 〈0.05）. And after CCD, the current amplitude were increased in both class 1 and 2 group, while only have significant difference in class 1 neurons （ P 〈 0.05 ）. Conclusion： The increase of the ratio in class 1 and class 2 after CCD model, accompanied by the amplitude increase of INaP in these 2 classes, contribute to the strengthening transmission from DRG to upper brain central.

关 键 词：兴奋性分型 背根神经节 阈下膜电位振荡 持续钠电流 

分 类 号：R363[医药卫生—病理学]