SWALLOWING & ESOPHAGEAL PERISTALIS--BRAINSTEM CIRCUITRY

吞咽是一种复杂的运动行为，其特点是协调 口腔、咽部、喉部和食道部肌肉收缩。 已经很好地确定了负责 颊咽和食道(原发)的起始和控制 蠕动)阶段的吞咽位于延髓内。这 中枢模式发生器(Cpg)被认为是一种神经元间质。 网络，一旦受到传入接触的刺激，就能够 协调运动神经元的连续兴奋，从而导致 以吞咽为特征的刻板印象的运动事件。尽管 CPG的电生理定位，人们对此知之甚少 神经连通性和神经化学，参与这一功能 电路。利用组织化学和免疫细胞化学技术，我们 提出对神经回路和神经递质的分析 用大鼠作为动物模型来控制吞咽。至 研究神经回路。伪狂犬病病毒(PRV)--一种新的 跨突触示踪剂，将被用来确定神经元间的 CPG神经元的组织。霍乱毒素-辣根过氧化物酶 用于确定吞咽运动神经元的树突结构。 核外树突状突起和/或核内树突的存在 树突束将为启动提供解剖学基础。 以及运动神经元活动的排序。为了研究神经递质， 双重标记，免疫组织化学技术将被用来确定 PRV免疫反应神经元(CPG神经元)的神经递质含量。一个 结合荧光示踪和免疫细胞化学技术将 用来显示大鼠感觉神经元的神经肽含量 NG的中枢投射与CPG神经元有突触联系。 这些研究将提供解剖学和神经化学分析 吞咽下的脑干回路，因此，可能具有直接的， 口咽部疾病的未来临床处理 食道功能和胃食道反流。

Swallowing is a complex motor behavior, characterized by the coordinated contraction of musculature in the mouth, pharynx, larynx, and esophagus. It is well established that the neural apparatus responsible for the initiation and control of the buccopharyngeal and esophageal (primary peristalsis) phases of swallowing are located within the medulla. This central pattern generator (CPG) has been thought of as an interneuronal network, that once stimulated by afferent contacts is capable of orchestrating the successive excitation of motoneurons that result in the stereotyped motor events that characterize swallowing. Despite the electrophysiological localization of the CPG, little is known about the neural connectivity and neurochemistry, involved in this functional circuitry. Utilizing histochemical and immunocytochemical techniques, we propose an analysis of the neural circuitry and the neurotransmitters underlying the control of swallowing using the rat as an animal model. To study the neural circuitry. Pseudorabies virus (PRV), a newly described transsynaptic tracer, will be utilized to determine the interneuronal organization of CPG neurons. Cholera toxin-horseradish peroxidase will be used to determine the dendritic architecture of swallowing motoneurons. The presence of extranuclear dendritic projections and/or intranuclear dendritic bundles would provide, anatomical substrates for the initiation and sequencing of motoneuronal activity. To study the neurotransmitters, double labeling, immunohistochemical techniques will employed to determine the neurotransmitter content of PRV immunoreactive neurons (CPG neuron). A combination of fluorescent tracing and immunocytochemical techniques will be utilized to demonstrate neuropeptide content of the sensory neurons in the NG whose central projections make synaptic contact with CPG neurons. These studies will provide an anatomical and neurochemical analysis of the brainstem circuitry underlying swallowing and thus, may have a direct, bearing on the future clinical management of disorders of oropharyngeal and esophageal function, and gastroesophageal reflux.