NEURONS AND GLIA IN VITRO

拟议的研究代表了研究的继续，在 体外，一些基本的生理和形态 哺乳动物神经胶质细胞和神经元的特性与离子的关系 脑细胞外间隙(ECS)的容量调节。 这项工作的长期目标是发现基本的 神经胶质细胞和神经元的特性相互作用来解释这种动态， 但在ECS中看到的调节、离子和体积波动 大脑活动。这项建议的一个新方向是研究这一点 在病态情况下的问题；具体地说，分析 成年期脑白质缺氧的病理生理学研究 和发育中的动物，使用分离的大鼠视神经(RON)。 分离的RONS，大鼠皮质组织切片，并培养 星形细胞，将在大多数实验中使用，并提供几个 相对于体内制剂的优势，包括易于获得的 ECS的灌注液，直接可视化 组织细胞的显微解剖特征，以及伟大的实验 灵活性。使用标准电生理记录 技术、离子敏感微电极和膜片钳 方法，将开展以下项目：1) 大鼠脑内胶质细胞生理学和形态的发育学研究 RON；2)膜片钳对培养的单个离子通道的研究 3)活性依赖和K诱导的变化分析 在RON和大脑皮层的PHO中；4)黄曲霉毒素的病理生理研究 白质中的缺氧，使用RON；5)关于 神经活动依赖和钾诱导内皮细胞的机制(S) 收缩；6)白种易感性的发育研究 造成缺氧损伤的物质。这些研究应该提供基本的新的 关于神经胶质细胞和神经元特性的信息，特别是 因为这些与正常和正常状态下脑内皮细胞离子动态平衡有关 病理情况。这些研究广泛地与 中风、新生儿窒息和脑肿胀的临床问题。

The proposed research represents a continuation of studies, in vitro, of some of the basic physiological and morphological properties of mammalian glia and neurons, in relation to the ionic and volume regulation of the extracellular space (ECS) of brain. The long term goals of this work are to discover how the basic properties of glia and neurons interact to account for the dynamic, but regulated, ionic and volume flucuations seen in the ECS with brain activity. A new direction for this proposal is to study this issue in a pathological circumstance; specifically, to analyze the pathophysiology of anoxia in white matter of the brain, in mature and developing animals, using the isolated rat optic nerve (RON). Isolated RONs, tissue slices from rat cortex, and cultured astrocytes, will be used in most experiments and offer several advantages over in vivo preparations, including ready access of perfusion solutions to the ECS, direct visualization of microanatomic features of the tissue cells, and great experimental flexibility. Using standard electrophysiological recording techniques, ion-sensitive microelectrodes, and the patch-clamp method, the following projects will be undertaken: 1) developmental study of glial cell physiology and morphology in the RON; 2) patch-clamp studies of single ion channels in cultured glia; 3) analysis of activity dependent and K+ - induced changes in pHo in the RON and cortex; 4) studies on the pathophysiology of anoxia in white matter, using the RON; 5) studies on the mechanism(s) of neural activity dependent and K+ - induced ECS shrinkage; 6) developmental studies on the susceptibility of white matter to anoxic injury. These studies should provide basic new information about the properties of glia and neurons, especially as these relate to ion homeostasis in brain ECS under normal and pathological conditions. These studies are broadly relevant to the clinical problems of stroke, neonatal asphyxia, and brain swelling.