Immunohistochemistry of cell adhesion molecules of developing circumvallate papillae and taste buds.

细胞粘附分子（CAM）是介导细胞-细胞粘附相互作用的膜相关糖蛋白。神经细胞粘附分子（N-CAM）介导的粘附参与神经发育和神经-肌肉相互作用。应用免疫细胞化学技术观察了N-CAM在小鼠轮廓乳头味蕾中的分布。在成年小鼠中，神经纤维和一些伸长的味觉观察表明，与神经有传入突触接触的III型（味觉）细胞在味蕾中呈N-CAM阳性。发育中小鼠的味蕾在出生后0天开始出现，随后在味蕾中发现N-CAN阳性细胞。这一结果表明，N-CAM 9参与了III型细胞和神经之间突触接触的形成。味蕾是已知的接触更新和神经诱导。在双侧舌咽神经切片后3天，在味蕾中发现N-CAM阳性细胞，如在对照中观察到的。切断双侧舌咽神经后第8天和第11天，在味蕾中发现N-CAM阳性细胞，与对照组相同。在切片后第8天和第11天，尽管数量减少，但仍观察到它们。很可能III型细胞总是合成N-CAM，以便在不久的将来与神经突触接触。另一方面，在使用单宁酸固定的电子显微镜观察的本研究中，我们在味蕾细胞和味孔中发现了具有磷脂特征的板层体。该体可充当表面活性剂以促进有味道的材料的溶解性，从而促进它们吸附到味蕾细胞的膜上。

Cell adhesion molecules (CAMs) are membrane-associated glycorpoteins that mediate cell-cell adhesive interactions. The neural cell adhesion molecule (N-CAM) sediated adhesion participates in meural development and nerve-muscle interactions. We observed the distribution of N-CAM in the taste buds of mouse circumvallate papillae by use of an immunocytochemical technique. In adult mice, nerve fibers and some elongated taste observation showed that type-III (gustatory) cells, which have afferent synaptic contacts with the nerves, were N-CAM positive in the taste buds. Taste buds of the developing mice first appeared at day 0 after birth, and then N-CAN positive cells were found in the taste buds. This result suggests that N-CAM 9s involved in formation of the synaptic contacts between type-III cells and nerves. Taste buds are known to be contacts renewed and neurally induced. At 3 days after sectioning of bilateral glossopharyngeal nerves, N-CAM positive cells were found in the taste buds as observed in controls. At 8 and 11 days after sectioning of bilateral glossophatyngeal nerves, N-CAM positive cells were found in the taste buds as observed in controls. At 8 and 11 days after sectioning, they were still observed although the number decreased. It is likely that type-III cells alwasys synthesize N-CAM for the purpose of a synaptic contact with the verves in the near future. In the other hand, in this study of electron microscopic observation by use of the fixation with tannic acid, we found lamellar bodies, characteristic of phospholipids, in the taste bud cells and taste pores. The bodies may act as a surfactant to promote the solubility of sapid materials to facilitate their adsorption to the membrane of the taste bud cells.