BLOOD PRESSURE CONTROL BY FOREBRAIN & BRAINSTEM NEURONS

前脑控制血压

• 批准号: 3344979
• 负责人: SUSAN M BARMAN
• 金额: $ 10.63万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-30 至 1991-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3344979
• 关键词: autonomic ganglion; autonomic reflex; baroreceptors; blood pressure; brain electrical activity; brain mapping; brain stem; cats; chemoreceptors; efferent nerve; electrophysiology; hypothalamus; interneurons; neural information processing; neuroanatomy; neurogenic hypertension; paraventricular nucleus; periaqueductal gray matter; pons; prosencephalon; sympathetic nervous system

The long range goal of the research supported by this grant is to identify electrophysiologically the central nervous system pathways that are involved in the control of cardiovascular function. During the current funding period we have used state- of-the-art electrophysiological analyses to identify major efferent and afferent connections of rostral ventrolateral medullary (VLM) neurons that likely account for their role in the control of sympathetic nerve discharge (SND) in the Dial-urethane anesthetized cat. The experiments described in this proposal extends the use of these techniques to studies of the hypothalamic paraventricular nucleus and dorsomedial hypothalamus (PVN- DMH) as well as the preoptic-anterior hypothalamic area (PO- AHA). These hypothalamic nuclei have recently received considerable attention as forebrain regions involved in the control of SND and blood pressure. PVN neurons project directly to the intermediolateral (IML) autonomic nucleus in the thoracolumbar spinal cords well as to brainstem autonomic regions (e.g., the nucleus tractus solitarius, the rostral VLM, the pontine locus coeruleus and parabrachial complex (LC/PB), and the mesencephalic periaqueductal gray (PAG)). PO-AHA neurons project to the PVN and to the LC/PB and PAG. Little information is currently available concerning the electrophysiological properties of PVN-DMH and PO-AHA neurons contained in these pathways. The brainstem regions innervated by PVN-DMH and PO-AHA neurons also provide input to these hypothalamic nuclei. Thus, feedback loops may play a role in controlling the activity within central sympathetic circuits. Recently, our laboratory has used the technique of spike-triggered averaging to identify two types of neurons in the PVN and PO- AHA whose spontaneous activity is correlated to that in the inferior cardiac sympathetic nerve in anesthetized cats. The spontaneous discharges of Type 1 neurons are synchronized to a spike-like component in inferior cardiac nerve activity, whereas the activity of Type 2 neurons is locked to the cardiac-related component in SND. It remains to be determined whether these hypothalamic neurons are involved in the control of resting SND. If both of these neuronal types control cardiovascular function, they probably do so by exerting their effects over different central pathways. The experiments outlined in this proposal are designed to determine which PVN-DMH and PO-AHA neurons are elements of efferent sympathetic (excitatory or inhibitory) pathways or interneurons in the afferent limb of the baroreceptor reflex arc. We also will be able to identify some of the major efferent and afferent connections of these neurons. The electrophysiological techniques to be used include spike-triggered averaging of SND, antidromic mapping and tests for axonal branching, and unit minus or greater than unit crosscorrelation analysis.

该赠款支持的研究的远距离目标是 从中枢神经系统上识别电生理学 涉及心血管控制的途径 功能。 在当前的资金期间，我们使用了州 - 现代电生理学分析以识别主要的效率 和连接连接的连接 可能解释其在控制中的作用的神经元 拨动尿素中的交感神经排出（SND） 麻醉猫。 该提案中描述的实验 将这些技术的使用扩展到下丘脑的研究 旁脑核和背侧下丘脑（PVN- DMH）以及下丘脑前 - PO- 啊哈）。 这些下丘脑核最近收到了 随着对控制涉及的前脑区域的关注 SND和血压。 PVN神经元直接向 胸骨中间人外侧（IML）自主核 脊髓以及脑干自主区域（例如 Nucleus tractus Solitarius，Rostral VLM，蓬蒂因特 凝结和副型络合物（LC/PB），以及 中脑周围灰色（PAG））。 po-aha神经元 投影到PVN以及LC/PB和PAG。 小的 目前可获得有关该信息的信息 PVN-DMH和PO-AHA神经元的电生理特性 包含在这些途径中。 脑干区域由 PVN-DMH和PO-AHA神经元也为这些提供了输入 下丘脑核。 因此，反馈循环可能在 控制中央交感神经中的活动。 最近，我们的实验室使用了尖峰触发的技术 平均在PVN和PO-中识别两种类型的神经元 啊哈，其自发活动与 麻醉猫的心脏下感神经。 这 1型神经元的自发放电与A同步 劣质心脏神经活动中的类似尖峰的成分，而 2型神经元的活性被锁定在与心脏有关 SND中的组件。 是否要确定这些是否 下丘脑神经元与静息SND的控制有关。 如果这两种神经元类型控制心血管功能， 他们可能是通过对不同的效果发挥作用来做到的 中央路径。 该提案中概述的实验是 设计以确定哪些PVN-DMH和PO-AHA神经元是 传出交感神经（兴奋性或抑制性）的要素 压力受体的传入肢体中的途径或中间神经元 反射弧。 我们还将能够确定一些专业 这些神经元的传出和传入连接。 这 要使用的电生理技术包括峰值触发 SND的平均，抗胶质图和轴突测试 分支，单位负或大于单位互相关 分析。