解剖学报 ›› 2016, Vol. 47 ›› Issue (5): 583-590.doi: 10.16098/j.issn.0529-1356.2016.05.002

• 神经生物学 • 上一篇    下一篇

小鼠背根神经节中痒觉神经元的分布特性

唐敏1,2 耿笑1 于雷1 朱婵1 杨雁1 王长明1 于光1 唐宗湘1*   

  1. 1. 南京中医药大学基础医学院,南京 210023; 2. 吉首大学生物资源与环境科学学院,湖南 吉首 416000
  • 收稿日期:2016-05-09 修回日期:2016-06-20 出版日期:2016-10-06 发布日期:2016-10-06
  • 通讯作者: 唐宗湘 E-mail:zongxiangtang@njutcm.edu.cn
  • 基金资助:

    Mrgprs基因的痒觉功能分析及天然致痒物的靶点筛选; 湖南省研究生创新项目

Distribution features of itch-specific neurons in dorsal root ganglion in mice

TANG Min 1,2 GENG Xiao1 YU Lei1 ZHU Chan1 YANG Yan1 WANG Chang-ming1 YU Guang1 TANG Zong-xiang 1*   

  1. 1. College of Basic Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China; 2. College of Biology and Environmental Sciences, Jishou University, Hu’nan Jishou 416000, China

  • Received:2016-05-09 Revised:2016-06-20 Online:2016-10-06 Published:2016-10-06
  • Contact: TANG Zong-xiang E-mail:zongxiangtang@njutcm.edu.cn
  • Supported by:

    Itch functional analysis of Mrgprs and target screening of pruritogenic substances from natrual products

摘要:

目的 观察小鼠背根神经节(DRG)中痒觉特异性MrgprA3+神经元的分布特征。方法 采用遗传学方法将MrgprA3+神经元特异性标记强化绿色荧光蛋白(EGFP)和tdTomato;选取3只纯合Mrgpra3EGFP-Cre;ROSA26tdTomato成年转基因小鼠,分离皮肤和背根神经节组织;采用激光扫描共焦成像技术观察MrgprA3+神经元的外周神经纤维在小鼠躯体皮肤的投射分布特征;采用双光子成像技术观察MrgprA3+ 神经元在整体背根神经节中的三维空间分布情况。结果 脸颊、背部和脚掌皮肤的MrgprA3+神经纤维分布密集,粗且长,分布广泛;颈部和腹部皮肤的MrgprA3+神经纤维分布稀疏,短且小,呈散点状分布;MrgprA3+神经纤维在皮肤的有毛和无毛区域都有投射分布,且不同部位分布特点不同;几乎所有的MrgprA3+神经元都为小直径感觉神经元,且在颈、胸、腰、尾段背根神经节中均有分布;颈段、胸段、腰段和尾段的Z轴成像深度分别为350μm、250μm、400μm和200μm;躯体不同部位背根神经节中的MrgprA3+神经元的三维空间分布在不同节段存在明显差异。 结论 小鼠躯体不同部位皮肤的MrgprA3+神经纤维的分布特征和整体背根神经节中MrgprA3+神经元的三维空间分布特征都存在较大差异,痒觉神经元和末梢分布的差异可能是不同区域存在痒觉生理反应差异的结构基础。

关键词: 痒觉神经元, 背根神经节, 激光扫描共焦成像, 双光子成像, 转基因小鼠

Abstract:

Objective To observe the distribution features of itch-specific MrgprA3neurons located in the dorsal root ganglion (DRG).Methods The MrgprA3+neurons were specifically labeled by enhaced green fluorescence protein(EGPF) and tdTomato using a genetic method. The skin and DRG tissues in the 3 adult homogenous transgenic Mrgpra3 EGFP-Cre ;ROSA26 tdTomato mice were collected. The peripheral MrgprA3+fibers innervating the skin were imaged by using confocal imaging technology. The distribution of MrgprA3+neurons in the intact DRG tissue was observed using two-photo imaging technology.Results The MrgprA3+fibers in cheek, back and paw skins were densely and widely distributed with clearly coarse and long features. By contrast, the MrgprA3+fibers in neck and abdomen skins were sparsely distributed with short and dotted features. The MrgprA3+fibers were distributed in both hairy and glabrous skins and showed different properties in various parts of body. Almost all of MrgprA3+neurons belonged to small diameter sensory neurons and located in the cervical, thoracic, lumbar and sacral DRG tissues. The Z axis imaging depth was 350μm in cervical DRG, 250μm in thoracic DRG, 400μm in lumbar DRG and 200μm in sacral DRG. Three dimensional spatial distributions of MrgprA3+neurons in various DRG tissues had significant differences.Conclusion The MrgprA3+fibers in various peripheral skin and MrgprA3+neurons located in intact DRG tissues show different distribution properties. The differences in the distribution of itch neurons and terminals may be the structural basis for the differences in the presence of itch sensation in different areas.

Key words: Itch-specific neuron, Dorsal root ganglion, Confocal imaging, Twophoto imaging, Transgenic mouse