Müller T, Jastrow H
Department of Anatomy, University of Mainz, Germany.
Arch Histol Cytol. 1998 Oct;61(4):327-36. doi: 10.1679/aohc.61.327.
The taste buds in the soft palate and the circumvallate papillae of the rat were investigated by the zinc iodide-osmium tetroxide technique. In addition, electron micrographs of taste buds stained with this method were presented for the first time. Differences in taste bud structures were found between the examined regions. The taste buds of the soft palate showed a complicated plexus of intragemmal nerve fibers. Some fibers exhibited terminal polymorphic swellings. Single branches could be traced close to the space of the taste pore. In the soft palate, the taste bud cells remained unstained, whereas in the circumvallate papillae of the tongue, a subpopulation of taste bud cells could be selectively stained and the intragemmal nerve fibers were characterized by large varicosities. The morphological dissimilarities between the taste buds of the investigated regions might be explained by their functional characteristics, or possibly their varying affinities to the taste qualities. Electron microscopic investigation of the stained circumvallate papillae revealed that the electron-dense reaction product had primarily accumulated in a subpopulation of light cells. Dark cells exhibited only a slight labelling. In detail, the precipitate was found loosely distributed in the cytoplasm as well as the nuclei of the cells, and particularly concentrated at the membranes of light vacuoles, this probably being profiles of dilated endoplasmic reticulum. A few roundish accumulations of precipitate were seen in the cytoplasm of taste bud cells, which showed no intensive light microscopic staining. Labelled material was also found within the taste pores outside the apical processes of the cells. The present findings indicate that the zinc iodide-osmium tetroxide technique is applicable to neuroanatomical studies of taste buds.
采用碘化锌-四氧化锇技术对大鼠软腭和轮廓乳头中的味蕾进行了研究。此外，首次展示了用该方法染色的味蕾的电子显微照片。在所检查的区域之间发现了味蕾结构的差异。软腭的味蕾显示出复杂的味蕾内神经纤维丛。一些纤维呈现出末端多形性肿胀。单个分支可追踪到靠近味孔的空间。在软腭中，味蕾细胞未被染色，而在舌的轮廓乳头中，一部分味蕾细胞可被选择性染色，且味蕾内神经纤维的特征是有大的膨体。所研究区域的味蕾之间的形态差异可能由它们的功能特性来解释，或者可能由它们对味觉品质的不同亲和力来解释。对染色的轮廓乳头进行电子显微镜研究发现，电子致密反应产物主要积聚在一部分亮细胞中。暗细胞仅显示轻微标记。具体而言，沉淀物松散地分布在细胞的细胞质以及细胞核中，并且特别集中在亮泡的膜上，这可能是扩张的内质网的轮廓。在味蕾细胞的细胞质中可见一些圆形的沉淀物积聚，这些细胞在光学显微镜下没有强烈染色。在细胞顶端突起之外的味孔内也发现了标记物质。目前的研究结果表明，碘化锌-四氧化锇技术适用于味蕾的神经解剖学研究。
