NEURONS AND GLIA IN VITRO

拟议的研究是研究的继续， 离体条件下，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 和脑细胞外间隙（ECS）的容量调节。 这项工作的长期目标是发现基本的 神经胶质和神经元的性质相互作用以解释动态， 但在ECS中观察到调节的离子和体积波动， 大脑活动 这项建议的一个新方向是研究这一点 在病理情况下的问题;具体来说，分析 脑白色物质缺氧的病理生理学， 和发育中的动物，使用分离的大鼠视神经（罗恩）。 分离的RON，来自大鼠皮质的组织切片，并培养 星形胶质细胞，将用于大多数实验，并提供几个 优于体内制剂的优点，包括易于获得 灌注溶液到ECS，直接可视化 组织细胞的显微解剖学特征，以及巨大的实验 灵活性. 使用标准的电生理记录 技术、离子敏感微电极和膜片钳 方法，将开展以下项目：1） 神经胶质细胞生理和形态的发育研究 罗恩; 2）膜片钳技术研究细胞膜上单个离子通道 活性依赖性和K+诱导的变化分析 在罗恩和皮质的pHo中; 4）病理生理学研究 白色物质缺氧，使用罗恩; 神经活动依赖性和K+诱导的ECS机制 收缩; 6）白色敏感性的发育研究 对缺氧损伤的影响。 这些研究将提供新的基础。 关于神经胶质细胞和神经元特性的信息，特别是 因为这些与在正常条件下脑ECS中的离子稳态有关， 病理条件。 这些研究广泛涉及 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.