Central Interaction of Baroreceptor & Somatic Afferents

压力感受器的中枢相互作用

基本信息

批准号：
7231706
负责人：
Jeffrey Thomas Potts
金额：
$ 0.36万
依托单位：
UNIVERSITY OF MISSOURI-COLUMBIA
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-04-01 至 2007-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7231706
关键词：
Agonist Aminobutyric Acid Aminobutyric Acids Anesthesia procedures Animals Award Baroreflex Brain Brain Stem Cardiovascular Physiology Cardiovascular system Cell Nucleus Data Disease Exercise Feedback Fiber GABA Receptor Heart Heart failure Homeostasis Hypertension In Situ Knowledge Mediating Microelectrodes Microinjections Motor Motor Activity Neurons Nociception Nucleus solitarius Pain Pathway interactions Physiological Preparation Pressoreceptors Process Rattus Reflex action Reporting Research Personnel Role Sensory Sensory Process Signal Transduction Skeletal Muscle Spinal Stress Substance P Substance P Receptor Synapses Synaptic Transmission Testing Work base blood pressure regulation expectation gamma-Aminobutyric Acid human study in vivo innovation neural circuit programs receptor relating to nervous system response sensory feedback sensory stimulus somatosensory young adult

项目摘要

DESCRIPTION (provided by applicant): Exercise alters arterial baroreceptor reflex function. However, the central mechanisms that modulate the arterial baroreflex during exercise are not completely understood. Arterial baroreceptor and skeletal muscle receptor afferents are stimulated during exercise and transmit sensory information to the nucleus tractus solitarii (NTS). The NTS is the major sensory nucleus in the mammalian brainstem that processes and relays these inputs to other medullary and supra-medullary nuclei controlling autonomic motor outflow. Previous work during the initial tenure of this award, along with preliminary data for this competitive renewal, has demonstrated that synaptic input from skeletal muscle receptors inhibits arterial baroreceptor signaling by activating local GABAergic and SPergic circuits in the NTS. The specific aims for this application are: 1) to determine the role GABAergic and SPergic mechanisms on central baroreflex control of vagal and sympathetic motor activity; 2) to characterize the synaptic responses of functionally-identified single-unit NTS neurons and to determine the contribution of GABAergic and SPergic receptors on neuronal and network excitability; and 3) to determine the role of innocuous and noxious feedback from skeletal muscle on arterial baroreflex function. To accomplish these aims, physiological paradigms will be used to activate arterial baroreceptors and contraction-sensitive / nociceptive skeletal muscle receptors using an in situ unanesthetized, arterially perfused working heart-brainstem preparation and an in vivo unanesthetized decerebrate preparation in young adult rats. The role of GABAergic and SPergic mechanisms in the NTS will be examined by central microinjections of selective agonists and antagonists for GABA receptors and neurokinin-1 receptors, as well as picoejection of these compounds directly onto functionally identified single-unit NTS neurons using multibarrel microelectrodes. Results from these studies will provide new information regarding the role of NTS neurons in the sensory processing of neural feedback from arterial baroreceptors and skeletal muscle receptors. This knowledge will extend our understanding of the central interaction between baroreceptor and somatic afferents at the level of the NTS and will provide a cellular basis to explain the synaptic mechanisms underlying baroreflex resetting during exercise.

描述（由申请人提供）：锻炼改变动脉压力感受器反射功能。但是，在运动过程中调节动脉压力反射的中心机制尚未完全理解。在运动过程中刺激了动脉压力感受器和骨骼肌受体传入，并将感觉信息传输到巨核Solitarii（NTS）。 NTS是哺乳动物脑干中的主要感官核，它将这些输入处理并传递到控制自主运动流出的其他髓质和上核核。该奖项最初任期期间的先前工作以及该竞争性更新的初步数据表明，骨骼肌受体的突触输入通过激活NTS中的局部Gabaergagic和spergic电路来抑制动脉压力感受器信号传导。该应用的具体目的是：1）确定对迷走神经和交感运动活动的中央压力控制控制中的GABA能和斑点机制； 2）表征功能识别的单单元NTS神经元的突触反应，并确定GABA能和Spergic受体对神经元和网络兴奋性的贡献； 3）确定骨骼肌无害和有害的反馈在动脉压力反射功能上的作用。为了实现这些目的，生理范例将用于激活动脉压力感受器和收缩敏感 /伤害感受性的骨骼肌受体，并使用原位的无效，动脉灌注的动脉灌注心脏脑部制备和体内未经动理的衰老成年成年成年成年成年幼虫的精神错乱。 GABA能和斑点机制在NTS中的作用将通过选择性激动剂和拮抗剂的中央显微注射来检查GABA受体和神经运动素-1受体，以及这些化合物的PICOEFOCTION，以及功能上功能上鉴定出的单个单位NTS神经元，使用多重生甲列内携带Microelectrodes。这些研究的结果将提供有关NTS神经元在动脉压力感受器和骨骼肌受体的神经反馈感觉过程中的作用的新信息。这些知识将扩展我们对NTS级别的压力感受器和体细胞传入者之间的核心相互作用的理解，并将提供一个细胞基础来解释运动过程中降压力反射重置的突触机制。