NEUROBIOLOGY OF GUSTATORY NEURONS IN SOLITARY NUCLEUS

这项研究旨在了解形态和突触 C 主要味觉中继核的组织及其在 品尝一下。味觉系统对人类的健康和生存起着至关重要的作用。 有机体的。它负责评估潜在的食品物质 用于接受或拒绝，也是 影响饮食选择的复杂习得行为和协调 口面部反射对于食物摄取是必不可少的。上半场1/3 孤束核是味觉的接受区。 传入信息。这也是味觉系统 发散成上升的成分，潜藏在知觉和享乐之下 味觉的方方面面，以及有助于协调 胃肠反射。尽管它们构成了不同的行为功能， 这两个子系统对它们的相对感觉并没有很好的理解 功能。生成这种细分的NST组织的性质 N 也是未知的。 延长的研究将使用形态学和电生理学 分析rostrol NST的输出神经元以开始深入研究 NST组织的成员。这些细胞要么在嘴上投射，要么上升 G 子系统，或尾部，进入脑干通路。形态实验 其中树枝的形态和产量的分布 神经元，通过逆行运输荧光示踪剂来识别，是 通过细胞内注射荧光黄揭示。电气 刺激传入周围神经将被用来比较神经元 关于传入投入来源、相对贡献的答复 来源和响应特征。时间复数脉冲串 刺激也将被用来研究二阶效应， 由神经元的固有属性产生或通过局部产生 突触回路，调节这些细胞的棘波后反应。 类似的记录实验将在体外制备中进行 建立输出神经元之间的对应关系 在体内和体外发挥作用。脑切片将建立一种准备 其中，吻侧NST内神经细胞类型之间的相互关系可以 用细胞内形态和电生理学进行研究 技巧。这些研究涉及几个新的和 味觉生理学的动力技术。 这些实验将根据1)内含子定义输出神经元的类别 C NST加工，2)传入输入，3)形态特征。 它们将为未来的对比实验提供必要的信息 已识别的NST神经元亚群中的味觉编码，并用于定义 未来NST神经元间突触相互作用的假说 工作。这项研究将有助于对该组织的了解 脑干和味觉系统的高级功能，以及基本感觉 整个神经系统的系统过程。

This research is directed toward understanding the morphological and synapt c organization of the primary gustatory relay nuclues and how it functions in taste. The gustatory system plays a vital role in the health and survival of the organism. It is responsible for evaluating potential food substance for acceptance or rejection, and is also an important afferent component in both complex learned behaviors influencing diet selection and coordinated orofacial reflexes essential for food ingestion. The rostral one-third of the nucleus of the solitary tract is the recipient zone for gustatory afferent information. It is also the point from which the gustatory system diverges into an ascending component, underlying the perceptual and hedonic aspects of taste, and a brainstem component contributing to coordination of ingestive reflexes. Although they underlie different behavioral functions, these two subsystems are not well understood as to their relative sensory functions. The properties of NST organization that generate this subdivisi n are also unknown. The prolonged studies will use morphological and electrophysiological analysis of output neurons in rostrol NST to begin an in-depth investigatio of NST organization. These cells project either rostrally, into an ascendi g subsystem, or caudally, into a brainstem pathway. Morphological experiment are planned, in which dendritic morphology and distribution of output neurons, identified by retrograde transport of fluorescent tracers, is revealed by intracellular injection of Lucifer Yellow. Electrical stimulation of afferent peripheral nerves will be used to compare neuronal responses in terms of the sources of afferent input, relative contributions of sources, and response characteristics. Temporally complex pulse train stimulation will also be used to investigate second order effects, either resulting from the neurons' intrinsic properties or produced via local synaptic circuitry, that modulate postspike responsiveness in these cells. Similar recording experiments will be carried out in an in vitro preparatio of the rostral NST, to establish the correspondence between output neuron function in vivo and in vitro. The brain slice will establish a preparatio in which interrelationships between neuronal cell types in rostral NST can be investigated using intracellular morphological and electrophysiological techniques. These studies involve the first application of several new and power techniques to gustatory physiology. These experiments will define classes of output neurons based on 1) intrins c NST processing, 2) access to afferent input, and 3) morphological features. They will provide information essential for future experiments comparing taste coding in identified subsets of NST neurons, and for defining hypotheses about synaptic interactions among NST neurons for future in vitr work. This research will contribute to understanding of the organization o brainstem and higher functions of the gustatory system, and basic sensory system processes throughout the nervous system.