VESTIBULO-CEREBELLAR CIRCUITS

这个子项目的主要目标是提供详细的 前庭自主神经的解剖结构特征 系统。这项研究分为两组相互关联但又相互独立的 实验。首先，这些研究人员此前已经证明，大脑中的神经元 前庭尾侧内侧核和前庭下核均有下降 投射到自主区和上升投射到 与自主神经功能有关的臂旁核。类似 臂旁核的上升投射来自更多的吻侧。 前庭上核区。第一个具体目标将解决 在大脑中是否存在独立或分支的神经元群体的问题 前庭核团通过以下方式产生升降投射 在每只动物体内注射两种不同的荧光示踪剂 标记前庭核神经元的分布以及前庭核团的存在 将确定是否存在双标记细胞。第二个目标是 确定臂旁区域是否与 前庭核团，再次使用多个顺行和逆行示踪剂 放置在不同的地区。第三个目标解决的问题是 前庭核神经元群负责特定的自主神经 反射，如心率、血压和呼吸的调节。 将谷氨酸分散注射到不同的核区 同时监测自主神经反射。 第二组实验试图确定是否存在和组织 与前庭自主神经相关的小脑微复合体 功能。第四个具体目标将确定自治相关区域 前庭核团接受来自特定矢状区的输入 小脑前叶和下橄榄的输入。在一些 实验中，顺行和逆行示踪剂都将被注入 小脑的不同区域，在前庭核有终末投射 并注意到下橄榄中标记的神经元。在其他实验中，区域 将在顺行后检查小脑和前庭核团的 示踪剂放在下层橄榄里。两组实验的结果 将根据区域地形进行比较和绘制地图。第五个具体目标 将讨论小脑和前庭核团区域是否组织成 目标4中确定的微复合体参与血压调节。 在监测的同时进行小脑区的电刺激 自主神经反射，然后前庭核团区域将被 荷包牡丹碱和诱发的反射重新检查。

The primary goal of this subproject is to provide detailed characterization of the anatomical organization of the vestibulo-autonomic system. The study is divided into two related, but separate sets of experiments. First, these investigators have previously shown that neurons in the caudal medial vestibular and inferior vestibular nuclei have both descending projections to autonomic regions and ascending projections to portions of the parabrachial nuclei that are associated with autonomic function. Similar ascending projections to the parabrachial nuclei arise from the more rostral region of the superior vestibular nucleus. The first specific aim will address the issue of whether separate or collateral neuronal populations in the vestibular nuclei give rise to the ascending and descending projections by injections of two different fluorescent tracers in each animal The regional distribution of labeled vestibular nuclei neurons, as well as the presence of absence of double labeled cells will be determined. The second aim will determine whether the parabrachial regions form reciprocal connections with the vestibular nuclei, again by using multiple anterograde and retrograde tracers placed in different regions. The third aim addresses the issue of which population of vestibular nuclei neurons is responsible for specific autonomic reflexes, such as modulation of heart rate, blood pressure, and respiration. Discrete injections of glutamate into different nuclear regions will be made while monitoring autonomic reflexes. The second set of experiments seeks to determine the existence and organization of cerebellar microcomplexes that are associated with vestibulo-autonomic function. The fourth specific aim will determine if autonomic related regions of the vestibular nuclei receive inputs from specific sagittal zones of the cerebellum anterior lobe and inputs from the inferior olive. In some experiments, both anterograde and retrograde tracers will be injected into different cerebellar regions, with terminal projections in the vestibular nuclei and labeled neurons in the inferior olive noted. In other experiments, regions of the cerebellum and vestibular nuclei will be examined following anterograde tracers placed in the inferior olive. Results from the two sets of experiments will be compared and mapped for regional topography. The fifth specific aim will address whether the cerebellar and vestibular nuclei regions organized into microcomplexes as determined in aim 4 are involved in blood pressure modulation. Electrical stimulation of cerebellar regions will be performed while monitoring autonomic reflexes, then vestibular nuclei regions will be blocked by bicuculline and the elicited reflexes re-examined.