GUSTATORY AFFERENT ORGANIZATION IN THE SOLITARY NUCLEUS

所提出的实验的目的是表征 味觉感受器亚群的敏感性和中枢代表性 在口腔中。 味觉功能的神经生理学研究， 特别是中枢神经系统，通常只刺激 味觉感受器的一个亚群， 前舌。 然而，除了舌头的前部， 感受器存在于上的叶状和轮廓状乳头 舌后部，颊壁上，鼻门齿管内和周围 硬腭和软腭上 拟议的实验将 使用本实验室最近开发的技术， 脑干中的味觉反应神经元，同时独立刺激 所有六组口腔味觉感受器。 第一中央神经元 本文将研究孤束核（NST）的味觉传递 在前三个实验中。 实验一和实验二的目的是 确定这些不同口味的反应的趋同程度， 受体组到单个神经元，以及解剖位点的 由这些受体亚群引起的反应。 化学 不同受体亚群的敏感性也将不同， 检查，最明显的是那些在上颚，因为化学敏感性 这些受体的特性才刚刚开始被描述。 的影响 同时刺激味觉感受器的不同亚群 将在第三个实验中阐明。 最后一组实验 将我们的研究扩展到第二中枢味觉神经元 臂旁核（PBN）。 在正常进食过程中， 可以同时刺激口腔中的味觉感受器，或者 快速地连续。 我们无法正确地破译味觉密码 味道影响进食行为的机制 如果不了解整个世界的感官冲击 受体表面 味觉系统对 摄食行为，以及涉及的自主神经和内分泌反应 维持能量、水和电解质平衡。 味觉 刺激物也会引起对食物和饮料的重要的享乐反应 这会导致不适当的摄入模式， 如肥胖和高血压等慢性疾病。

The objectives of the proposed experiments are to characterize the sensitivity and central representation of gustatory receptor subpopulations in the oral cavity. Neurophysiological studies of taste function, particularly in the central nervous system, have usually stimulated only one subpopulation of taste receptors, the fungiform papillae on the anterior tongue. In addition to the anterior tongue, however, taste receptors are present in the foliate and circumvallate papillae on the posterior tongue, on the buccal wall, in and around the nasoincisor ducts of the hard palate, and on the soft palate. The proposed experiments will use techniques recently developed in this laboratory to record from taste-responsive neurons in the brainstem, while independently stimulating all six groups of oral gustatory receptors. Neurons in the first central gustatory relay, the nucleus of the solitary tract (NST), will be studied in the first three experiments. Experiments One and Two are designed to determine the degree of convergence of responses from these distinct taste receptor groups onto single neurons, as well as the anatomical loci of responses arising from these receptor subpopulations. The chemical sensitivities of the different receptor subpopulations will also be examined, most notably those on the palate because the chemical sensitivity of these receptors has only begun to be characterized. The effects of simultaneously stimulating separate subpopulations of gustatory receptors will be elucidated in the third experiment. The final set of experiments will extend our investigation to neurons in the second central gustatory relay, the parabrachial nuclei (PBN). During normal feeding, all the gustatory receptors in the oral cavity may be stimulated simultaneously, or in rapid succession. We cannot properly decipher the code for gustatory quality or the mechanisms through which taste influences feeding behavior without understanding the sensory barrage that arises from the entire receptor surface. The gustatory system exerts powerful influences on ingestive behavior, as well as autonomic and endocrine responses involved in the maintenance of energy, water, and electrolyte balance. Gustatory stimuli also exemplify the important hedonic responses to foods and drink that contribute to inappropriate ingestion patterns and that exascerbate such chronic conditions as obesity and hypertension.