Neural Plasticity in the Adult Gustatory System

描述（由申请人提供）：味蕾对神经支配的依赖性已被用作理解神经/焦油相互作用的模型。神经支配的丧失导致味蕾正常形态外观的丧失，而神经支配的恢复导致味蕾形态和功能的恢复。成年人的味觉再生系统特别容易受到环境的影响。结合单侧鼓索神经切断和低钠饮食在成年大鼠的味蕾和再生神经的各种功能和解剖学的改变。此外，功能和解剖学上的改变也发生在舌的完整的对侧。除了与鼓索神经的外周部分相关的损伤诱导效应外，还存在涉及切片神经的中央部分的极端形态学变化。协调研究将利用单侧鼓索神经切断和饮食钠限制联合诱导的显著功能和解剖可塑性。系统水平的方法将集中在成年大鼠味觉系统的神经可塑性。结合解剖学、神经生理学、电子显微镜和免疫细胞化学技术，可以确定：1）正常成年人单个味蕾神经支配随时间的稳定性，并确定鼓索神经元重新支配其原始靶点的准确性; 2）NTS终末区可塑性的范围和性质; 3）NTS突触可塑性的范围和性质;单侧鼓索神经切断和/或饮食钠限制对NTS味觉反应的功能影响。这些研究的结果将涉及更广泛的主题，感觉编码，神经活动在维持感觉功能中的作用，以及在正常情况下和对神经损伤的反应中外周神经支配的时间稳定性和准确性。研究结果也将使人们能够更清楚地了解人类味觉神经损伤的神经生物学后遗症持续病理，或在中耳或口腔手术。

DESCRIPTION (provided by applicant): The dependence of taste buds on innervation has been used as a model to understand nerve/tar interactions. Loss of innervation results in a loss of the normal morphological appearance of taste buds, while restoration of innervation results in a recovery of taste bud morphology and function. The adult regenerating gustatory system is especially susceptible to environmental manipulations. Combining unilateral chorda tympani nerve section and low sodium diet in adult rats results in a variety of functional and anatomical alterations in both taste buds and in the regenerating nerve. Furthermore, functional and anatomical alterations also occur in the intact, contralateral side of the tongue. In addition to injury-induced effects related to the peripheral portion of the chorda tympani nerve, there are also extreme morphological changes that involve the central portion of the sectioned nerve. Coordinated studies will take advantage of the remarkable functional and anatomical plasticity induced by combined unilateral chorda tympani nerve section and dietary sodium restriction. A systems-level approach will focus on neural plasticity in the adult rat gustatory system. Combined anatomical, neurophysiological, electron microscopic, and immunocytochemical techniques will permit a determination of: 1) the stability of innervation of single taste buds over time in normal adults and determine the accuracy of chorda tympani neurons in reinnervating their original targets; 2) the extent and nature of terminal field plasticity in the NTS; 3) the extent and nature of synaptic plasticity in the NTS; and 4) the functional consequences of unilateral chorda tympani nerve section and/or dietary sodium restriction on taste responses in the NTS. Findings from these studies will address the broader topics of sensory coding, the role of neural activity in maintenance of sensory function, and the temporal stability and accuracy of peripheral innervation under normal circumstances and in response to nerve damage. Results will also enable a clearer understanding of the neurobiological sequelae of human taste nerve damage sustained pathologically, or during middle ear or oral surgery.