CARDIAC SENSORY INTEGRATION IN CERVICAL SPINAL CORD

描述：拟议研究的长期目标是 提供了对中枢神经整合的理解， 解释与心肌相关的疼痛的产生或抑制 缺血 目前这组实验的重点是分析一种 第一颈椎至第三颈椎中的特定细胞群 可以抑制脊髓丘脑束中的传输的节段。 这一假说认为，具有下行投射的高位颈神经元 参与处理感官内脏信息， 伤害性输入和远端脊髓节段。 具体目标旨在回答以下问题。 1)并 化学刺激或灭活高颈段神经元 影响胸腰骶部脊髓丘脑束神经元的活动？ 2)感觉内脏输入是否能兴奋颈椎脊髓本体神经元 进入不同的脊椎节段 3)迷走神经刺激会兴奋吗 颈椎脊髓神经元 4)突触连接是否 延髓孤束核对颈迷走神经的作用 神经元？ 5)心脏刺激是否能兴奋颈脊髓本体神经元 感觉信息在迷走神经纤维、交感神经纤维或两者中传播 传入神经纤维的类型 6)心肌缺血是否影响 颈椎脊髓神经元的活动 神经生理学技术将用于解决这些目标。 在 第一个特定目标，胸腰骶部细胞外电位 将在猴子中记录脊髓丘脑束神经元以确定 刺激或灭活颈部神经元的作用。 在特定 目的2 - 6，颈椎固有脊髓神经元的细胞外电位 胸段或腰段的投影将记录在 猴子来确定对内脏刺激的反应。 从这些研究中得出的数据将作为以下方面的重要依据： 了解人类"无症状"心肌缺血的现象。 这个项目应该提供深入了解中枢神经机制 参与抑制内脏伤害性信息。 因此，在本发明中， 这些结果有望提供神经生理学基础， 解释了在患有以下疾病的患者中观察到的疼痛阈值升高： 经历心肌缺血而没有疼痛，并有突发性 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.