Immunohistochemical study on the sensory and autonomic nerve fibers in dental pulp and periodontium.

本课题组用尿素银浸渍法和透射电镜对牙体组织的感觉神经支配进行了多年的研究。虽然这些方法对显示神经在牙体组织中的分布和超微结构是有用的，但其来源和性质仍有待进一步阐明。因此，神经系统特异性蛋白的免疫组织化学技术被引入神经元的形态学研究。本文用神经丝蛋白（NFP）和S-100蛋白的抗血清对人牙、大鼠磨牙和大鼠牙周组织的神经支配进行了研究。采用设计的固定、脱钙和脱钙成分免疫染色方法。清晰地展示了人牙本质和前牙本质神经的三维结构，并对人牙齿的感觉机制进行了探讨。在大鼠磨牙中，发现牙本质和前牙本质中的NFP阳性纤维直接穿透牙本质小管。然而，在人类牙齿中没有观察到显示三维延伸的复杂神经纤维。光镜下观察到大鼠磨牙牙周膜内存在大量Ruffini样小体。这些神经末梢被认为在牙周膜中起牵张感受器的作用。本文用光镜和电镜首次发现大鼠磨牙前牙本质中存在降钙素基因相关肽（CGRP）神经纤维，并讨论了CGRP神经元的功能意义。

Sensory innervation in the dental tissues has been studied for years in our group with the aid of the urea silver impregnation method and the transmission electron microscope. Although the methods were useful for demonstrating the distribution and ultrastructure of nerves in the dental tissues, their origin and nature remained to be further clarified. Thus, the technique of immunohistochemistry for nervous system-specific proteins was introduced to study the morphology of neural elements. With the use of antisera against neurofilament protein (NFP) and S-100 protein which are specific for neurons and glial elements, respectively, the innervation in human teeth, rat molars, and rat periodontium was discussed. With the methods devised for fixation, decalcification and immunostaining of decalcified components. The three-dimensional constitution of nerves in the human dentin and predentin was clearly demonstrated, and the sensory mechanism of human teeth was discussed. In rat molar teeth, the NFP-positive fibers in the dentin and predentin were found to penetrate directly into the dentinal tubules. However, complex nerve fibers showing three-dimensional extension as recognized in human teeth were not observed. In the periodontal ligament of rat molars, the presence of numerous Ruffini-like corpuscles was revealed in the light microscopy. These nerve terminals are considered to function as stretch receptors in the periodontal ligament. The nerve fibers showing calcitonin gene-related peptide (CGRP) were first shown to be present in the predentin of rat molars with light and electron microscopes, and the functional significance of peptidergic neurons was discussed.