Acid-base balance in brain extracellular fluid (EDF) and control of breathing

脑细胞外液 (EDF) 中的酸碱平衡和呼吸控制

基本信息

批准号：
61570364
负责人：
ARITA Hideho
金额：
$ 1.6万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

The present project has revealed the following new findings on dynamic properties and locations of the central chemoreceptors.1. In order to stimulate repeatedly the central chemoreceptors, we developed a technique of vertebral arterial injections of CO2-saturated saline in decerebrated, spontaneously breathing cats. The injections evoked an initial transient inhibition of ongoing respiratory activity, followed by the subsequent excitation: the initial inhibition was due to activation of vascular nociceptors and the subsequent excitation due to stimulation of the central chemoreceptors (J. Appl. Physiol.).2. Applying this technique, we studied the changes in activity of medullary neurons (146 units) with non-phasic discharges. Eighteen units were found to be excited exclusively by stimulation of the central chemoreceptors (namely, possible candidates for pH-sensitive neurons), and they were distributed mainly in the vicinity of ventral respiratory group (VRG) neurons as well as in the … More dorsal area ventral to the solitary tract (ST), though less in number (Brain Res. 1988).3. Using liquid membrane pH microelectrodes, we found intramedullary regions in which ECF pH shifted to the acid side in the same time course as respiratory excitation when CO2 in the vertebral artery was raised in stepwise fashion. These areas were found to overlap with the regions of "possible candidates for pH-sensitive neurons"4. The regions described above were revealed to be supplied by the following vessels (by means of Technovit); the anterior inferior cerebellar artery, the Posterior inferior cerebellar artery and an unnamed artery arising from the basilar artery.Based upon the foregoing evidence, we have hypothesized that the central chemoreceptors would consist of pH-sensitive neurons and the surrounding structures (capillaries and glial cells) which regulate ECF pH, and that they are located in the vicinity of the VRG and in the dorsal area ventral to the ST, which were perfused by the vertebral basilar arterial system. Less

本项目揭示了以下有关中央化学感受器动态特性和位置的新发现。1。为了反复刺激中央化学感受器，我们开发了一种椎动脉注射二氧化碳饱和盐水的椎动脉注射技术，该技术在杂交的，赞助的呼吸猫中。注射引起了对正在进行的呼吸活性的初始短暂抑制，其次是随后的兴奋：初始抑制是由于血管伤害感受器的激活以及由于刺激中央化学感受器的刺激引起的兴奋（J.Appl。Physiol。）。应用这项技术，我们研究了具有非强调放电的髓质神经元（146个单位）的活性变化。发现十八个单元仅通过刺激中心化学感受器（即可能的pH敏感神经元的候选物）而极度兴奋，并且它们主要分布在腹侧呼吸组（VRG）神经元的附近，以及在…腹侧（sodart tract tract tract tract（ST））中，虽然是脑部（sT），但在数量中更少。使用液体膜pH微电极，我们发现了髓内区域，其中当CO2以逐步升高椎动脉抬起时，ECF pH与呼吸兴奋的同一时期转移到酸侧。发现这些区域与“ pH敏感神经元可能的候选者”区域重叠4。上述区域显示由以下船只（通过技术）提供；脑部下动脉，后脑下动脉和由基底动脉引起的无名动脉。基于上述证据，我们认为，中心的化学感受器将由pH敏感的神经元和周围的结构（墨西哥玉米饼和胶状细胞）组成的pH和pH和pH的pH和pH的vic vic and ecf and ecf and ecf and ecf and ecf conde and ecf ecf and ecf ecf nien and ecf。 to的背区域腹部是由椎骨基底动脉系统灌注的。较少的