电针对神经病理性疼痛伴发焦虑大鼠行为学及缰核HCN1表达的影响

Effect of Electroacupuncture on Behavior and Expression of Hyperpolarization-activated Cyclicnucleotide-gated Channels 1 in Rats with Neuropathic Pain Accompanied by Anxiety

[目的]观察电针(electro-acupuncture,EA)对神经病理性疼痛伴发焦虑大鼠行为学的干预作用,以及对缰核中超极化激活环核苷酸门控通道蛋白1(hyperpolarization-activated cyclicnucleotide-gated channels 1,HCN1)和c-fos表达的影响,部分阐明神经病理性疼痛伴发精神障碍的发病机制及EA的干预机制。[方法]32只雄性SD大鼠按完全随机法分为空白对照组、假手术组、坐骨神经分支选择性损伤(sciatic nerve branch selective injury,SNI)组和EA组,每组8只。SNI组和EA组以SNI法制备神经病理性疼痛模型,模型制备第8天起,EA组选取"足三里""昆仑"两穴,以EA治疗,每次30min,1次/d,共3次,其余组别不予治疗。造模前,造模后l、3、5、7、8、9和10d检测机械性缩足反射,造模后第10天采用旷场实验观察大鼠的焦虑情绪,免疫荧光检测缰核HCN1与c-fos的表达。[结果]造模第1天起,与空白对照组比较,假手术组大鼠患侧机械性痛阈各时点差异无统计学意义(P>0.05),SNI组大鼠较假手术组下降(P<0.01);与SNI组比较,EA组大鼠各时点机械性痛阈均上升(P<0.01);4组大鼠健侧机械性痛阈无明显变化(P>0.05)。旷场实验中,SNI组大鼠运动总距离、进入中央区次数、中央区运动距离均低于假手术组(P<0.01,P<0.01,P<0.05),而中央区停留时间仅低于空白对照组(P<0.05),EA组大鼠运动总距离、进入中央区次数和中央区停留时间均少于SNI组(P<0.05,P<0.01,P<0.01),中央区运动距离差异无统计学意义(P>0.05)。各组大鼠健侧内侧缰核(medial habenular nucleus,MHb)、外侧缰核外侧部分(lateral habenular nucleus lateral part,LHb L)和外侧缰核内侧部分(lateral habenular nucleus medial part,LHbM)的HCN1表达差异无统计学意义(P>0.05);与假手术组比较,SNI组患侧各部分HCN1表达水平均增高(P<0.01,P<0.01,P<0.01);与SNI组比较,EA组患侧HCN1表达水平均降低(P<0.01,P<0.01,P<0.01)。各组大鼠健侧MHb与LHb L的c-fos表达差异无统计学意义(P>0.05);与假手术组比较,SNI组健侧LHbM以及患侧MHb、LHbL的c-fos表达也显著增高(P<0.01,P<0.05,P<0.01),而两组患侧LHbM的c-fos表达差异无统计学意义(P>0.05);EA组双侧c-fos的表达均低于SNI组同侧(P<0.01,P<0.01)。[结论]大鼠患侧缰核HCN1通道可能参与了神经病理性疼痛伴发焦虑的发生,而干预缰核HCN1的表达可能是EA调控神经病理性疼痛伴发精神障碍的机制之一。

[Objective]To observe the behavioral intervention of electro-acupuncture(EA)on neuropathic pain accompanied by anxiety in rats and its influence on hyperpolarization activated cyclicnucleotide-gated channels 1(HCN1)and c-fos expression in habenular nucleus,and partly clarify the mechanism of neuropathic pain accompanied by psychiatric disorders and EA intervention.[Methods]Thirty-two male SD rats were randomly divided into blank control group,Sham group,sciatic nerve branch selective injury(SNI)group and EA group.Neuropathic pain model was built by SNI method in SNI group and EA group,from the 8 th day of modeling,rats in EA group were treated with EA for 30 minutes with acupoints of"Zusanli"and"Kunlun",one time per day,for 3 days,and the other groups were not treated.Detection of mechanical foot retraction reflex was tested before and 1,3,5,7,8,9 and 10 days after modeling to study the changes of bilateral mechanical pain threshold in rats.The anxiety in rats were observed on the 10 th day after modeling using open field experiment.Immunofluorescence was used to detect the expression of HCN1 and c-fos in habenular nucleus.[Results]Compared with blank control group,there was no statistically significant difference in mechanical paw withdrawal thresholds(MPWTs)on affected side in Sham group(P>0.05).Compared with Sham group,MPWTs in SNI group decreased(P<0.01);compared with SNI group,MPWTs increased at all time points in EA group(P<0.01).There was no significant difference in MPWTs on the healthy sides in all groups(P>0.05).In open field experiment,the total movement distance,the times of entering the central region,the central region movement distance of SNI group were less than that of Sham group(P<0.01,P<0.01,P<0.05),while the central region residence time was less than blank control group(P<0.05);total movement distance,the times of entering the central region and the central region residence time of EA group was less than SNI group(P<0.05,P<0.01,P<0.01),and there was no significant change in the central region movement distance(P>0.05).There was no statistically significant difference in HCN1 expression of medial habenular nucleus(MHb),lateral habenular nucleus lateral part(LHbL)and lateral habenular nucleus medial part(LHbM)on the healthy side in all groups(P>0.05).Compared with Sham group,the expression of HCN1 on the affected side in SNI group increased(P<0.01,P<0.01,P<0.01);compared with SNI group,the expression of HCN1 on the affected side in EA group decreased(P<0.01,P<0.01,P<0.01).There was no significant difference in expression of c-fos of MHb and LHbL on healthy sides in all the groups(P>0.05).Compared with Sham group,expression of c-fos of LHbM on healthy side(P<0.01),expression of c-fos of MHb and LHbL on affected side in SNI group were higher(P<0.05,P<0.01);while there was no statistically significant difference in expression of c-fos of LHbM on affected sides between the two groups(P>0.05).Compared with SNI group,the expression of c-fos on both sides in EA group was lower than the same side in SNI group(P<0.01,P<0.01).[Conclusion]HCN1 channel may be involved in neuropathic pain accompanied by anxiety in the affected side of habenular nucleus in rats,and EA intervention of HCN1 expression in habenular nucleus may be one of the mechanisms regulating neuropathic pain accompanied by mental disorders.