SENSORY AND RESPIRATORY INTEGRATION IN C1-C2 SPINAL CORD

描述(改编自申请人的摘要)：目标 这项建议是为了获得关于内脏组织的知识 上颈髓的感觉处理。近期 观察导致了这样的概念，即这个区域可能整合了内脏 调节伤害反应的信息。初步证据显示 大鼠提示具有下行投射的上颈部神经元 处理有害输入以对感官产生抑制效应 在较低的网段中传输。此外，还有一组下行的 C_1~C_2节段的神经元有呼吸相放电。不清楚 已发现这些神经元对正常呼吸有贡献。一个 以前没有考虑过的可能功能是 内脏传入高位颈呼吸神经元可能影响 向下流出以产生呼吸困难的感觉。整体而言 假设具有下行投射的上颈部神经元是 由内脏脊髓传入和迷走神经传入兴奋，因此可以调节 下脊椎节段的神经元活动。设计了具体的目标 回答以下问题：1)什么是解剖学 上颈椎固有脊髓的分布和神经化学含量 神经元？2)上颈椎的化学激活/失活 神经元影响脊髓臂或脊丘脑束神经元 胸腰椎节段？3)C1-C2是下降的吗？ 内脏兴奋的固有脊髓神经元，包括呼吸神经元 传入输入？4)什么是电生理、形态和 术后观察单个C1-C2神经元的神经化学特征 细胞内渗透？神经解剖学、免疫组织化学和 将使用神经生理学技术来确定基本信息 关于上颈固有脊髓神经元，包括呼吸系统 神经元。从这些研究中得出的数据将提供对 中枢神经机制可能涉及的条件，如 自主神经反射障碍，无症状性心肌缺血和呼吸困难。

DESCRIPTION (Adapted from the applicant's abstract): The objective of this proposal is to gain knowledge about the organization of visceral sensory processing in the upper cervical spinal cord. Recent observations led to the concept that this region may integrate visceral information to modulate nociceptive responses. Preliminary evidence in rats suggests that upper cervical neurons with descending projections process noxious inputs to produce inhibitory effects on sensory transmission in lower segments. Additionally a group of descending neurons in C1-C2 segments have respiration-phased discharge. No clear contribution to normal breathing has been found for these neurons. A possible function that has not been considered previously is that visceral input to high cervical respiratory neurons may influence the descending outflow to produce the sensation of dyspnea. The overall hypothesis is that upper cervical neurons with descending projections are excited by visceral spinal input and vagal input, and thus could modulate neuronal activity in lower spinal segments. Specific aims are designed to answer the following questions: 1) What is the anatomical distribution and neurochemical content of upper cervical propriospinal neurons? 2) Does chemical activation/inactivation of upper cervical neurons affect spinoparabrachial or spinothalamic tract neurons in thoracic and lumbosacral segments? 3) Are C1-C2 descending propriospinal neurons, including respiratory neurons, excited by visceral afferent inputs? 4) What are the electrophysiologic, morphologic and neurochemical characteristics of single C1-C2 neurons examined after intracellular penetration? Neuroanatomical, immunohistochemical and neurophysiological techniques will be used to determine basic information about upper cervical propriospinal neurons, including respiratory neurons. Data derived from these studies will provide understanding of central neural mechanisms which may be involved in conditions such as autonomic dysreflexia, silent myocardial ischemia, and dyspnea.