VESTIBULO-CEREBELLAR CIRCUITS

该子项目的主要目标是提供详细的 前庭自主神经解剖结构的表征 系统这项研究分为两个相关的，但独立的一套， 实验首先，这些研究人员先前已经表明， 前庭神经尾侧内侧核和前庭神经下核都有降神经 向自主区域的投射和向部分自主区域的上行投射。 与自主神经功能相关的臂旁核。类似 向臂旁核的上行投射起源于较吻侧的 前庭神经上级核的区域。第一个具体目标是解决 是否单独的或侧支神经元群体的问题， 前庭神经核产生上行和下行投射， 在每只动物中注射两种不同的荧光示踪剂。 标记的前庭核神经元的分布，以及 确定不存在双标记细胞。第二个目标将 确定臂旁区是否与臂间区形成相互连接。 前庭神经核，再次使用多个顺行和逆行示踪剂 放在不同的地区。第三个目标涉及的问题是， 前庭神经核神经元的群体负责特定的自主神经功能， 反射，如心率、血压和呼吸的调节。 将谷氨酸盐离散注射到不同的核区域 同时监测自主神经反射 第二组实验试图确定 小脑微复合体与前庭自主神经 功能第四个具体目标将确定自主相关区域是否 的前庭核接受来自特定矢状区的输入， 小脑前叶和输入来自下橄榄。在一些 实验中，顺行和逆行示踪剂都将被注入到 小脑不同区域，前庭核有终末投射 并在下橄榄核中标记了神经元。在其他实验中， 小脑和前庭核的检查将在顺行 在下橄榄核中放置示踪剂。两组实验的结果 将进行比较并绘制区域地形图。第五个具体目标 将讨论小脑和前庭核区域是否组织成 目的4中确定的微复合物参与血压调节。 在监测的同时进行小脑区域的电刺激 自主反射，那么前庭核区域将被阻断， 荷包牡丹碱和引起的反射重新检查。

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.