Raphe Nuclei Projections to Vestibular Nuclei

描述(由申请人提供)：本研究项目的目标是描述从中缝核团到前庭系统的投射的组织结构。尽管中缝核团发出的纤维支配着前庭核团，但人们对中缝-前庭通路的具体组织知之甚少。这个项目的第一部分将使用顺行追踪来检查中缝投射到前庭核团的地形图。然而，由于中缝投射既来自5-羟色胺能神经元，也来自非5-羟色胺能神经元，我们设计了一种新的实验技术组合，将允许独立分析5-羟色胺能和非5-羟色胺能成分的终止模式。本研究还涉及中缝向上升网络投射的组织，有助于前庭与自主神经通路的相互作用。我们将检验这一假设，即5-羟色胺能和非5-羟色胺能中缝神经元是这个上升网络组成部分的侧支轴突投射的来源--特别是前庭、臂旁外侧核、中央杏仁核和下丘脑室旁核。我们将使用多种逆行示踪方法来识别这些侧支投射。

DESCRIPTION (provided by applicant): The goal of this research project is to characterize the organization of projections from the raphe nuclei to the vestibular system. Although fibers originating from raphe nuclei are known to innervate the vestibular nuclei, little is known about the specific organization of the raphe-vestibular pathway. The first part of this project will use anterograde tracing to examine the topography of raphe projections to the vestibular nuclei. However, because raphe projections arise from both serotonergic and non-serotonergic neurons, we have devised a novel combination of experimental techniques that will allow the termination patterns of the serotonergic and non-serotonergic components to be analyzed independently. The present research is also concerned with the organization of raphe projections to an ascending network that contributes to vestibular interactions with autonomic pathways. We will test the hypothesis that serotonergic and non-serotonergic raphe neurons are sources of collateralized axon projections to components of this ascending network - specifically the vestibular, lateral parabrachial, central amygdaloid, and hypothalamic paraventricular nuclei. We will use multiple retrograde tracer methods to identify these collateralized projections.