Takahashi Natsumi, Nakamuta Nobuaki, Yamamoto Yoshio
Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate, 020-8550, Japan.
Histochem Cell Biol. 2016 Feb;145(2):131-46. doi: 10.1007/s00418-015-1371-x. Epub 2015 Oct 16.
The morphological characteristics of P2X3-immunoreactive nerve endings in the laryngeal mucosa were herein examined using immunohistochemistry with confocal laser microscopy. Ramified intraepithelial nerve endings immunoreactive to P2X3 were distributed in the epiglottis and arytenoid region. The axon terminals of P2X3-immunoreactive ramified endings were beaded or flat in shape. These endings were also immunoreactive to P2X2 and not identical to the nerve endings immunoreactive to Na(+)-K(+)-ATPase α3-subunit, substance P (SP), and calcitonin gene-related peptide (CGRP). P2X3-immunoreactive axon terminals were also immunoreactive to vGLUT1, vGLUT2, and vGLUT3. In addition to ramified endings, P2X3-immunoreactive nerve endings were associated with α-gustducin-immunoreactive solitary chemosensory cells and/or SNAP25-immunoreactive neuroendocrine cells. Furthermore, P2X3-immunoreactive nerve endings were also observed in the taste bud-like chemosensory cell clusters of the stratified squamous epithelium covering epiglottic and arytenoid cartilage. The P2X3-immunoreactive nerve endings that associated with sensory and/or endocrine cells and chemosensory cell clusters were also immunoreactive to P2X2, vGLUT1, vGLUT2, and vGLUT3, but not to SP or CGRP. In conclusion, P2X3-immunoreactive nerve endings may be classified into two types, i.e., intraepithelial ramified nerve endings and nerve endings associated with chemosensory cells and neuroendocrine cells.
本文利用免疫组织化学结合共聚焦激光显微镜检查了喉黏膜中P2X3免疫反应性神经末梢的形态学特征。对P2X3呈免疫反应性的分支状上皮内神经末梢分布于会厌和杓状软骨区域。P2X3免疫反应性分支末梢的轴突终末呈串珠状或扁平状。这些末梢对P2X2也呈免疫反应性，且与对Na(+)-K(+)-ATP酶α3亚基、P物质（SP）和降钙素基因相关肽（CGRP）呈免疫反应性的神经末梢不同。P2X3免疫反应性轴突终末对囊泡谷氨酸转运体1（vGLUT1）、囊泡谷氨酸转运体2（vGLUT2）和囊泡谷氨酸转运体3（vGLUT3）也呈免疫反应性。除了分支末梢外，P2X3免疫反应性神经末梢还与α-味导素免疫反应性孤立化学感受细胞和/或突触小体相关蛋白25（SNAP25）免疫反应性神经内分泌细胞相关。此外，在覆盖会厌和杓状软骨的复层鳞状上皮的味蕾样化学感受细胞簇中也观察到了P2X3免疫反应性神经末梢。与感觉和/或内分泌细胞以及化学感受细胞簇相关的P2X3免疫反应性神经末梢对P2X2、vGLUT1、vGLUT2和vGLUT3也呈免疫反应性，但对SP或CGRP不呈免疫反应性。总之，P2X3免疫反应性神经末梢可分为两种类型，即上皮内分支神经末梢和与化学感受细胞及神经内分泌细胞相关的神经末梢。
