DEVELOPMENT OF FUNGIFORM PAPILLA AND TASTE BUDS

该方案中的实验旨在研究 感觉神经与靶器官的相互作用 发展。这些研究的模型系统是菌状乳头。 (FP)和味蕾(TBS)。每个乳头都是 鼓索(CT)由两条感觉神经支配，它支配 TBS和舌部，三叉神经的一个分支， 为乳头和整个粘膜提供体感神经支配 舌头的前部，但基本上被排除在结核病之外。 我们计划用一种新的方法来研究TBS的发展和 乳头状，对组织的扰动最小。1)我们将在子宫内使用 手术在CT到达舌上皮之前中断它，以及 抑制三叉神经发育的免疫手段，以 确定切除其中一条或两条神经对分化的影响 FP和他们的结核病。2)我们将进行免疫组织化学研究 神经生长前和神经生长过程中舌组织细胞外基质的变化 确定矩阵的组织方式是否可能提供 神经在人体内生长时所遵循的路径 舌头朝向黏膜。3)我们将进行免疫组织化学研究 发育期大鼠舌头FP值判断神经生长 因子(NGF)或NGF受体在FP中有不同的存在 上皮、结核和神经。这样做的理由是基于 观察到三叉神经节细胞需要神经生长因子来维持其功能 而CT神经节细胞则不能。有可能是因为 神经为什么不同地分布于大脑的不同部位 FP是相应的神经营养因子，如NGF，需要 每条神经都是由它们所支配的上皮细胞构成的，即， 舌周围细胞和CT神经的TB细胞。

The experiments in this proposal are designed to investigate the interactions between sensory nerves and their target organs during development. The model system for these studies is the fungiform papillae (FP) and taste buds (TBs) on the embryonic rat tongue. Each papilla is innervated by two sensory nerves, the chorda tympani (CT), which innervates TBs exclusively, and the lingual, a branch of the trigeminal nerve, which provides somatosensory innervation to the papilla and the entire mucosa of the anterior part of the tongue, but is essentially excluded from the TB. We plan to use a novel approach to study the development of TBs and papillae with minimum perturbation of the tissue. 1) We shall use in utero surgery to interrupt the CT before it reaches the tongue epithelium, and immunological means to inhibit development of the trigeminal nerve, to determine how removal of either or both nerves affects differentiation of the FP and their TB. 2) We shall do immunohistochemical studies on the extracellular matrix of the tongue before and during nerve growth to determine whether the matrix is organized in a way that might provide a pathway for the nerves to follow as they grow through the body of the tongue toward the mucosa. 3) We shall do immunohistochemical studies on the FP of rat tongue during development to determine whether nerve growth factor (NGF) or NGF-receptors are differentially present in the FP epithelium, TB and nerves. The rationale for this is based on the observation that trigeminal ganglion cells require NGF for their maintenance, whereas CT ganglion cells do not. It is possible that the reason why the nerves are differentially distributed to different parts of the FP is that the respective neurotrophic factors, such as NGF, required by each nerve are made by those epithelial cells that they innervate, i.e., perigemmal cells for the lingual and TB cells for the CT nerves.