HYPOTHALAMIC CONTROL OF THE CARDIORESPIRATORY SYSTEM

下丘脑对心肺系统的控制

• 批准号: 2219009
• 负责人: TONY G WALDROP
• 金额: $ 13.41万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-04-01 至 1995-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2219009
• 关键词: baroreceptors; brain mapping; cardiovascular system; cats; cerebral ischemia /hypoxia; chemoreceptors; efferent nerve; electrophysiology; experimental brain lesion; heart innervation; hypothalamus; microinjections; neural conduction; neural information processing; neuropharmacology; neurotransmitters; phrenic nerve; pulmonary stretch receptors; respiration regulatory center; respiratory function; respiratory reflex; single cell analysis; spinal cord; spontaneous hypertensive rat; stretch reflex; sympathetic nervous system; tissue /cell culture; voltage /patch clamp

The long-term goal of research in this laboratory is to elucidate the role of caudal hypothalamic neurons in regulating cardiorespiratory activity. The specific aims are to: 1) provide evidence for the physiological function of caudal hypothalamic neurons; 2) identify stimuli which alter the discharge of identified neurons; 3) determine projections of caudal hypothalamic neurons to lower brainstem and spinal cord sites; and 4) examine possible contributions of caudal hypothalamic neurons to elevated pressure present in spontaneously hypertensive rats. Both in vivo and in vitro preparations will be used to address these aims. The first set of experiments will be performed in anesthetized cats. Computer signal averaging techniques will be utilized to correlate basal discharge frequency of hypothalamic neurons with the cardiac cycle, sympathetic nerve activity and/or phrenic nerve activity. In addition, single unit responses of these neurons to various stimuli (hypoxia, hypercapnia, baroreceptor activation, pulmonary stretch receptor stimulation) will be recorded. An attempt will then be made to determine the axonal projection of all neurons studied using antidromic activation and mapping techniques. An in vitro rat brain slice preparation will be utilized to evaluate the direct effects of hypoxia and hypercapnia upon caudal hypothalamic neurons. Whole cell patch recordings will be performed in the brain slice experiments; retrograde transport of rhodamine microbeads will be used in an attempt to determine projection sites of studied neurons. In vivo experiments will also be undertaken in spontaneously hypertensive rats (SHR) to determine if neuronal activity in the caudal hypothalamus is altered relative to that of normotensive rats. Computer averaging techniques will determine the proportion of caudal hypothalamic neurons which have a cardiac and/or sympathetic discharge. Each neuron will also be tested for a response to baroreceptor stimulation. In a final set of experiments, characteristics of hypothalamic neurons from SHR rats will be compared to those of normotensive rats in a brain slice preparation. Comparisons will be made between neurons from young and mature spontaneously hypertensive rats and with normotensive controls. The results of these studies may offer insight into neurological abnormalities contributing to the origination and/or maintenance of high blood pressure and altered cardiorespiratory reflexes.

该实验室研究的长期目标是阐明角色 尾丘脑神经元在调节心肺活性中的作用。 具体目的是：1）为生理提供证据 尾丘脑神经元的功能； 2）识别刺激变化 鉴定神经元的排出； 3）确定尾骨的预测 下丘脑神经元降低脑干和脊髓部位；和4） 检查尾丘脑神经元对升高的可能贡献 自发性高血压大鼠的压力。 体内和 体外准备工作将用于解决这些目标。 第一组 实验将在麻醉猫中进行。 计算机信号 平均技术将用于相关 心脏周期，交感神经的下丘脑神经元的频率 活性和/或神经活动。 此外，单位响应 这些神经元的各种刺激（缺氧，高碳酸脂蛋白，压力受体 将记录激活，肺拉伸受体刺激）。 一个 然后将尝试确定所有神经元的轴突投影 使用抗肿瘤激活和映射技术进行了研究。 体外 大鼠脑切片准备将用于评估直接效果 尾端下丘脑神经元的缺氧和高碳酸血症。 全细胞 贴片记录将在大脑切片实验中进行； 将使用若丹明微粒的逆行运输将用于尝试 确定研究神经元的投影位点。 体内实验将 也可以在自发的高血压大鼠（SHR）中进行 相对于尾骨下丘脑的神经元活性相对于 正常的大鼠。 计算机平均技术将确定 具有心脏和/或具有心脏的尾丘脑神经元的比例 交感神经排放。 每个神经元还将测试 压力感受器刺激。 在最后一组实验中，特征 将SHR大鼠的下丘脑神经元的下丘脑神经元与 脑切片制剂中的正常大鼠。 将进行比较 在年轻和成熟的自发性高血压大鼠和成熟的神经元之间 具有正常的控制。 这些研究的结果可能会提供洞察力 进入神经异常，导致起源和/或 维持高血压和心肺反射改变。