CARDIAC SENSORY INTEGRATION IN CERVICAL SPINAL CORD

描述：拟议研究的长期目标是 提供对中枢神经整合的理解， 解释与心肌炎相关的疼痛的产生或抑制 缺血症。当前一系列实验的重点是分析一个 第一颈椎至第三颈椎的特定细胞群 可能抑制脊髓丘脑束传播的节段。 假说是颈部高位神经元具有下行投射 参与处理感官内脏信息，抑制 伤害性输入和远端脊椎节段。 具体目标旨在回答以下问题。1)做到了 高位颈段神经元的化学刺激或失活 影响胸腰段脊髓丘脑束神经元的活动？ 2)颈固有脊髓神经元是由感觉内脏传入兴奋的吗？ 进入不同的脊柱节段？3)迷走神经刺激会兴奋吗？ 颈固有脊髓神经元？4)是突触连接 颈髓孤束核在迷走神经效应中的作用 神经元是心脏兴奋的颈固有脊髓神经元吗？ 感觉信息在迷走神经纤维和/或交感神经纤维中传递 传入神经纤维的类型？6)心肌缺血会影响 颈固有脊髓神经元的活动？ 神经生理学技术将被用来解决这些目标。在 第一个特定目标，胸椎和腰椎的细胞外电位 将记录猴的脊髓丘脑束神经元以确定 刺激或失活颈部神经元的效果。具体而言 AIMS 2-6，颈髓固有神经元的细胞外电位 对胸椎或腰椎节段的投影将被记录在 确定猴子对内脏刺激的反应。 从这些研究中得出的数据将作为 了解人类“无症状”心肌缺血的现象。 这个项目应该提供对中枢神经机制的洞察力 参与抑制内脏伤害性信息。因此， 这些结果有望提供神经生理学基础 解释在以下患者中观察到的痛阈值升高 经历无痛心肌缺血，有猝发风险 死亡。

DESCRIPTION: The long term objective of the proposed research is to provide an understanding of the central neural integration that could explain production or suppression of pain associated with myocardial ischemia. The focus of the current set of experiments is to analyze a specific group of cells in the first cervical to third cervical spinal segments that could inhibit transmission in the spinothalamic tract. The hypothesis is that high cervical neurons with descending projections are involved in processing sensory visceral information that inhibits nociceptive inputs and distant spinal segments. Specific aims are designed to answer the following questions. 1) Does chemical stimulation or inactivation of neurons in high cervical segments affect activity of thoracic and lumbosacral spinothalamic tract neurons? 2) Are cervical propriospinal neurons excited by sensory visceral inputs that enter different spinal segments? 3) Does vagal stimulation excite cervical propriospinal neurons? 4) Are synaptic connections in medullary nucleus tractus solitarius needed for vagal effects in cervical neurons? 5) Are cervical propriospinal neurons excited by cardiac sensory information traveling in vagal fibers, sympathetic fibers or both types of afferent neural fibers? 6) Does myocardial ischemia affect activity of cervical propriospinal neurons? Neurophysiological techniques will be used to address these aims. In the first specific aim, extracellular potentials of thoracic and lumbosacral spinothalamic tract neurons will be recorded in monkeys to determine effects of stimulating or inactivating cervical neurons. In Specific Aims 2-6, extracellular potentials of cervical propriospinal neurons with projections to thoracic or lumbar segments will be recorded in monkeys to determine responses to visceral stimuli. The data derived from these studies will serve as a important basis for understanding the phenomenon of "silent" myocardial ischemia in humans. This project should provide insights into central neural mechanisms involved in suppression of visceral nociceptive information. Thus, these results are expected to provide a neurophysiological basis to explain the elevated pain threshold that is observed in patients who experience myocardial ischemia without pain and are at risk for sudden death.