TRPV1对慢性压迫背根节神经元自发放电的作用  

Role of TRPV1 in ectopic spontaneous activity of chronic compressed DRG neurons

作　　者：刘大路[1] 王文挺[2] 杜兰芳[2] 郑大伟[2] 胡三觉[2] 

机构地区：[1]第四军医大学口腔医学系 [2]第四军医大学基础部神经科学研究所,陕西西安710033

出　　处：《第四军医大学学报》2009年第15期1345-1348,共4页Journal of the Fourth Military Medical University

基　　金：国家自然科学基金重点项目(30530260)

摘　　要：目的:研究瞬时受体电位V1受体(TRPV1)对受压迫背根节(DRG)神经元自发放电的影响.方法:在麻醉消毒手术条件下,经大鼠L5椎间孔插入长4mm直径0.5～0.8mm不锈钢丝,以形成对大鼠DRG及其神经根的稳定慢性压迫.观察模型动物的行为学特征,引导损伤侧背根A类单纤维自发放电,观察分析TRPV1受体拮抗剂Capsazepin作用下,自发放电频率的变化及特征.结果:模型动物表现出明显的疼痛行为.术后24h其损伤侧后肢每分承重分散时间延长为(10.5±2.1)s/min(P<0.05).大部分慢性压迫模型(32/35)表现为自发放电阳性,按其特征分为周期放电(14例)、非周期放电(18例).在Capsazepin(3μmol/L)浸浴作用下,受损DRG神经元自发放电频率明显下降,周期放电频率由(27.7±2.2)Hz下降至(15.5±2.0)Hz(n=4,P<0.05);非周期放电的放电频率由(34.7±7.4)Hz下降至(17.2±5.2)Hz(n=10,P<0.05).结论:阻断TRPV1后,由DRG慢性压迫诱发的自发放电被部分抑制.TRPV1可能参与受损DRG神经元自发放电的产生,介导了神经病理痛信号的产生和传导.AIM： To study the effect of the Capsazepin（CZP） , a blocker of the transient receptor potential subfamily vanilloid member 1 （TRPV1）, on the spontaneous firing with different pattern originating from the injured dorsal root ganglion（DRG）. METHODS： Under anesthesia and sterilized surgery, a piece of stainless steel filament（4 mm in length and 0.5-0.8 mm in diameter） was inserted into L5 intervertebral foramen in rats, thus producing a steady and chronic compression on the DRG and its nerve root. The behaviors of models were observed and ectopic spontaneous discharges originating from neurons of the compressed DRGs were recorded through single dorsal root fiber. The characteristics and the frequency of firing from both the CZP-treated A type afferents and that of control were analyzed. RESULTS： Twenty-four hours after the compression, significant pain behaviors were observed in the models. The weight distribution period was obviously prolonged to （ 10.5 ± 2. 1 ） s/min （ P 〈 0.05 ）. Most compressed DRG neurons （32/35） displayed large ectopic spontaneous activities, including 14 with periodic pattern and 18 with nonperiodic pattern. After the bath of CZP（3 μmol/L） in the compressed DRG, the frequency of most（14/22） ectopic spontaneous discharges dropped obviously from （ 27. 7 ± 2. 2 ） Hz to （ 15.5 ± 2.0 ） Hz （ n = 4, P 〈 0.05 ） for regular activities, and from （34.7 ±7.4） Hz to （17.2±5.2） Hz （n=10, P〈0.05） for nonperiodic activities. CONCLUSION： After blocking TRPV1, the ectopic spontaneous activities of the compressed DRG neurons are restrained, indicating that TRPV1 may involve in the process of inducing and maintaining the ectopic spontaneous activities from compressed DRG neurons and may mediate the transmission of the neuropathic pain from DRGs to CNS.

关 键 词：瞬时受体电位V1受体 CAPSAZEPINE 背根节 电生理 

分 类 号：Q424[生物学—神经生物学]