解剖学报

解剖学报 ›› 2019, Vol. 50 ›› Issue (2): 152-157.doi: 10.16098/j.issn.0529-1356.2019.02.003

• 神经生物学 • 上一篇    下一篇

小鼠背根神经节慢性压迫引起的痛敏化机制

陶金1 王涛1 朱杰2 马超1*   

  1. 1.中国医学科学院基础医学研究所, 北京协和医学院基础学院人体解剖学与组织学胚胎学系，北京 100005; 2.北京协和医学院临床医学系，北京 100005
  • 收稿日期:2018-12-12 修回日期:2018-12-27 出版日期:2019-04-06 发布日期:2019-04-06
  • 通讯作者: 马超 E-mail:taojinjoy123@163.com
  • 基金资助:
    国家自然科学基金;国家自然科学基金;重大研究计划(培育项目;上海市自然科学基金与基础重大重点研究;上海市自然科学基金与基础重大重点研究;中国医学科学院医学与健康科技创新工程协同创新团队项目

Mechanisms of pain hypersensitivity in a mouse model of chronic compression of dorsal root ganglia 

 TAO Jin1 WANG Tao1 ZHU Jie2 MA Chao 1*   

  1. 1.Department of Anatomy, Histology and Embryology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 10005, China; 2.Department of Clinical Medicine, Peking Union Medical College, Beijing 100005, China
  • Received:2018-12-12 Revised:2018-12-27 Online:2019-04-06 Published:2019-04-06
  • Contact: MA Chao E-mail:taojinjoy123@163.com

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摘要：

目的 探讨背根神经节慢性压迫（CCD）引起的低剂量辣椒素诱发痛敏化机制。 方法 将光滑L型钢柱插入小鼠的L4椎间孔，对背根神经节（DRG）造成持续压迫，建立小鼠CCD模型。于CCD术前1 d及术后第1、3、5、7 d向小鼠胫骨前区皮下注射不同浓度的辣椒素（0.01、0.1、1 g/L）10 μl后采用行为学检测动物的痛行为学表现并录像，以寻找CCD术后辣椒素诱发痛行为差异最显著的浓度。利用Pirt-GCaMP3转基因小鼠，胫骨前区皮下注射最佳浓度辣椒素，利用激光扫描共焦显微镜在体记录DRG神经元对外周体表感受野辣椒素刺激的反应。利用免疫荧光染色技术观察正常及CCD模型压迫5 d后DRG内辣椒素受体（TRPV1）的表达变化。 结果 行为学检测结果显示，与正常小鼠相比，低浓度（0.1 g/L）辣椒素在CCD模型小鼠上引起的诱发痛显著提升（n=8; 术后1 d，P<0.01；术后5 d，P<0.05；术后7 d，P<0.05；术后3 d，P> 0.05）。在体激光扫描共焦成像结果表明，在记录的398（n=4）个正常小鼠L4 DRG神经元中，对皮下注射0.1 g/L辣椒素有反应的神经元为75个，在382（n=6）个CCD术后5 d的小鼠L4 DRG神经元中，对皮下注射0.1 g/L辣椒素有反应的神经元为169个，差异有显著性（P<0.01）。免疫荧光染色结果显示，在653（n=10）个正常神经元中，TRPV1阳性的细胞数为148，在611（n=6）个CCD神经元中，TRPV1阳性的细胞数为237，差异有显著性（P<0.01）。 结论 在小鼠CCD模型中，受到压迫DRG神经元TRPV1表达上调，导致相应的体表感受区域对辣椒素诱发痛敏化。

关键词: 腰背痛, 辣椒素, 辣椒素受体1, 背根神经节慢性压迫模型, 在体激光扫描共焦成像, 小鼠

Abstract:

Objective To investigate the mechanisms of pain hypersensitivity to lowdose capsaicin in a mouse model of chronic compression of dorsal root ganglion (CCD). Methods Chronic compression of L4 DRG was performed in mice by inserting an L-shaped stainless steel rod into the L4 intervertebral foramina. Different doses of capsaicin（0.01, 0.1, 1 g/L）1 μl were injected into the skin on the calf area and behavior responses were videotaped on pre-CCD 1 days and post-CCD 1, 3, 5, 7 days. The optimal concentration that led to a significant difference after CCD was determined and was used in the following in-vivoDRG imaging studies. Immunofluorescent staining was conducted to evaluate the expression of transient receptor potential vanilloid 1 (TRPV1) in DRG from na?ve and CCD mice. Results Behavioral tests showed that 0.1 g/L capsaicin elicits a significant difference in pain-like behaviors after CCD（n=8; post-CCD 1 day, P<0.01; post-CCD 5, 7 days P<0.01; post-CCD 3 days, P> 0.05. In vivocalcium imaging showed an enhanced number of activated DRG neurons to the injection of capsaicin in CCD mice, which was 75 in total of 398(n=4) for control mice and 169 in total of 382(n=6) (P<0.01). According to immunofluorescent staining results, there were 148 TRPV1+ neurons in total 653 counted neurons (n=10) for control mice and 237 TRPV1+ neurons in total of 611 neurons (n=6) for CCD mice (P<0.01). Conclusion Chronically compressed DRG neurons show upregulated TRPV1 receptor and enhanced responses to low-dose capsaicin, that produce pain hypersensitivity in the CCD mice.

Key words: Chronic pain, Capsaicin, Transient receptor potential vanilloid 1, Chronic compression of dorsal root ganglia, Laser scanning confocal imaging in viro, Mouse