EFFERENT INNERVATION OF IDENTIFIED VESTIBULAR AFFERENTS

这项资助的目的是为了研究大脑的传出神经支配 外周前庭器官。关于化学成分的知识 脑干传出神经元向外周的投射 迷路可能有助于理解前庭传出神经的作用 健康和疾病方面的系统。最近的研究表明，神经元 在传出核内的递质可能是异质的 神经化学和他们的外周目标。这一建议 如果异质性得到证实，将改变我们长期以来的观点，即 前庭传出神经是一种非特异性系统。这项研究的目标是 确定栗鼠传出神经元的亚群 他们的脑干位置，他们的投射到一个或另一个或两者都有 耳朵，它们的神经化学特征和毛发上的外周末端 细胞、花萼和其他传入突起。具体目标是：L)到 描述传出神经的解剖学和神经化学亚群 脑干传出神经元的逆行示踪剂和 递质免疫组织化学；2)与中枢相关。 前庭传出神经元亚群到它们的终末 外围设备。脑干中的传出神经元将通过 向周围前庭器官逆行注射示踪剂 并将同时通过使用免疫组织化学来表征 几种可能的神经递质抗体(乙酰胆碱， 降钙素基因相关肽、一氧化氮合酶、甲硫氨酸脑啡肽和 其他)。分析将扩展到外围，其中电子 将使用显微免疫组织化学方法来表征 神经化学上独特的传出神经根据它们的 感觉上皮中的终末，也就是按传入的类别 (花萼、二态或突起)或区域(中心或外围)，它们 令人兴奋。前庭传入神经将通过以下方式识别 细胞外HRP注射、Calretinin免疫组织化学或其他 意思是。M受体亚型的分布也将是 研究试图理解传入神经对 刺激传出神经。这个项目的意义在于 对构成人口的各种要素的准确了解 传出神经元和它们在外围的靶点，将进一步推动我们的 了解脑干对外周感觉加工的控制。它 希望作为这项工作的结果，它将不再足够 仅仅是为了定义脑干中的亚群，而不是建立它们的 与周边国家的关系。这也不足以说明 外围设备端接，但未说明其在 安多根。其目的是要产生一个关于 传出的生理和生理基础的结构基础 可以得出药理学上可检验的假说。

The purpose of this grant is to investigate the efferent innervation of the peripheral vestibular apparatus. Knowledge of the chemical composition and projections of the efferent neurons in the brainstem to the peripheral labyrinth may help to understand the role of the vestibular efferent system in health and disease. Recent work has suggested that the neurons in the efferent nucleus may be heterogeneous in their transmitter neurochemistry and in their peripheral targets. This suggestion of heterogeneity, if confirmed, would change our long-held view that the vestibular efferents are a nonspecific system. The goal of this study is to define subpopulations of efferent neurons in the chinchilla based on their brain stem locations, their projections to one, the other or both ears, their neurochemical identities and their peripheral endings on hair cells, calyces and other afferent processes. Specific aims are: l) to characterize anatomical and neurochemical subpopulations of efferent neurons in the brainstem efferent neurons using retrograde tracers and transmitter immunohistochemistry, and 2) to relate the central subpopulations of vestibular efferent neurons to their terminations in the periphery. Efferent neurons in the brainstem will be identified by means of retrograde tracer injections into the peripheral vestibular apparatus and will be simultaneously characterized immunohistochemically by the use of antibodies to several putative neurotransmitters (acetylcholine, calcitonin gene-related peptide, nitric oxide synthase, met-enkephalin and others). The analysis will be extended to the periphery where electron microscopic immunohistochemical methods will be used to characterize neurochemically distinctive efferent boutons according to their terminations in the sensory epithelium, that is, by the class of afferents (calyx, dimorphic or bouton) or region (central or peripheral) that they innervate. Vestibular afferents will be identified by means of extracellular HRP injections, calretinin immunohistochemistry, or other means. The distribution of muscarinic receptor subtypes will also be examined in an attempt to understand the slow response of afferents to stimulation of the efferents. The significance of this project is that a precise knowledge of the various elements comprising the population of efferent neurons, and their targets in the periphery, will further our understanding of brain stem control of peripheral sensory processing. It is hoped that as a result of this work, it will no longer be sufficient merely to define subgroups in the brain stem without establishing their relationship to the periphery. Nor will it be sufficient to illustrate peripheral terminations without stating their specific location within the endorgan. The intent is to produce a body of knowledge about the structural basis of the efferents from which physiologically and pharmacologically testable hypotheses can be derived.