Kanazawa H, Yoshie S
Department of Anatomy, Niigata University School of Medicine, Japan.
Arch Histol Cytol. 1996 Oct;59(4):357-67. doi: 10.1679/aohc.59.357.
The taste bud in the rat vallate papillae was observed by immunohistochemistry for PGP 9.5 at the light and electron microscope levels; routine transmission electron microscopy was also performed. Immunoreactivity for PGP 9.5, a marker protein of paraneurons, was localized in the cytoplasm of the Type III or gustatory cells. More intensive immunoreactivity occurred in the nerve fibers, though a part of the nerve fibers remained unstained. The nerve fibers as detected by the immunostaining and by routine electron microscopy formed a coarse subepithelial plexus which issued branches upwards through the basal lamina. In the basal portion of the taste bud, these fibers formed a hitherto unknown intragemmal plexus of dense and delicate meshwork. This plexus, in turn, extended beaded fibers between the taste bud cells, forming synaptic contacts with Type III cells. Some of the immunoreactive nerve fibers were confirmed to reach the taste pore by light microscopy; electron-microscopic examination could not demonstrate their directly being exposed to the space of the taste pore. This study also deals with the fine structure of the rat taste bud with special reference to the Type III cells and their synapses with nerve fibers, as the rat has recently been rather seldom used in this field of study.
采用免疫组织化学方法，在光镜和电镜水平下观察大鼠轮廓乳头中的味蕾；同时进行常规透射电子显微镜检查。副神经节细胞的标记蛋白PGP 9.5的免疫反应性定位于III型或味觉细胞的细胞质中。神经纤维中的免疫反应性更强，不过部分神经纤维未被染色。通过免疫染色和常规电子显微镜检测到的神经纤维形成了一个粗大的上皮下丛，该丛通过基膜向上发出分支。在味蕾的基部，这些纤维形成了一个迄今未知的、密集且精细的味蕾内丛。这个丛反过来在味蕾细胞之间延伸出串珠状纤维，与III型细胞形成突触联系。通过光镜证实一些免疫反应性神经纤维到达了味孔；电镜检查未能证明它们直接暴露于味孔空间。由于大鼠最近在该研究领域较少被使用，本研究还特别探讨了大鼠味蕾的精细结构，尤其是III型细胞及其与神经纤维的突触。
