辣椒素处理对电针“四白”穴诱导三叉神经脊束核尾侧亚核c-fos表达的影响

目的:探讨四白穴针刺效应的传入途径。方法:SD大鼠36只,随机分成空白组、假手术组、辣椒素组、溶媒组、电针"四白"穴+辣椒素组、电针"四白"穴+溶媒组。游离一侧眶下神经,辣椒素组将浸泡有1.5%辣椒素的棉条包绕在眶下神经上。溶媒组用浸泡在溶媒中的棉条包绕在眶下神经上。采用免疫组化技术观察三叉神经脊束核尾侧亚核(cSTN)的c-fos表达。结果:空白组在cSTN各层可见到零星、散在的阳性细胞。溶媒组、辣椒素组以及假手术组cSTN的c-fos阳性细胞数与空白组相似。电针"四白"穴+溶媒组c-fos在cSTN内主要集中在浅层(Ⅰ-Ⅱ层),其阳性细胞的数量明显多于其余各组(P<0.01);cSTN的深层(Ⅲ-Ⅳ层)c-fos数量多于空白组、溶媒组和假手术组(P<0.01,P<0.05,P<0.05)。电针"四白"穴+辣椒素组cSTN的Ⅰ-Ⅱ板层的c-fos阳性细胞数与电针"四白"穴+溶媒组相比明显减少(P<0.01),但cSTN的Ⅲ-Ⅳ板层的c-fos阳性细胞数与电针"四白"穴+溶媒组相比无明显变化(P>0.05)。结论:C纤维可能是四白穴针刺效应(调节胃功能活动)的主要传入途径。

Effect of Capsaicin-pretreatment on "Sibai" (ST 2)-electroacupuncture Induced Changes of c-fos Expression in Rat Caudal Spinal Trigeminal Nucleus

Objective To explore the afferent pathway of signals from electroacupuncture(EA)at "Sibai"(ST 2)acupoint.Methods A total of 36 SD rats were randomly divided into control,sham operation(sham),capsaicin,vehicle,capsaicin+EA,and vehicle+EA groups,with 6 cases in each.EA(1/20 Hz,1-3 mA)was applied to "Sibai"(ST 2).After anesthesia(10% urethane),unilateral infraorbital nerve was separated to be immersed in a 1.5% capsaicin-fluid-soaked cotton ball for lesion of C fibers.Vehicle(20% tween)was used to immerse infraorbital nerve for vehicle and vechile+EA groups.The expression of c-fos in the caudal spinal trigeminal nucleus(cSTN)was detected by immunohistochemistry.Results In control group,c-fos immune-reaction(IR)positive neurons were observed to scatter in every layer of cSTN.No significant differences were found among vehicle,capsaicin,sham and control groups in the number of c-fos IR positive neurons in cSTN.The number of c-fos positive neurons in theⅠ-Ⅱ layers of cSTN was obviously increased following EA at ST2,being significant more than that in control,vehicle,capsaicin and sham groups(P<0.01 respectively).However,the number of c-fos IR-positive neurons in Ⅲ-Ⅳ layers of cSTN had no marked change.In capsaicin+EA group,the number of c-fos-IR positive neurons in theⅠ-Ⅱ layers of cSTN was obviously less than that in vehicle and vehicle+EA groups(P<0.01),but no significant changes were found in Ⅲ-Ⅳ layers of cSTN.Conclusion C afferent fibers of the infraorbital nerve are the primary afferent pathway of EA signals from Sibai(ST 2)stimulation in the rat.