IONIC MOVEMENTS ACROSS NERVE CELL BODY MEMBRANES

将使用电生理学检查钙通道功能 方法. 本建议针对的是以下具体方面： 开放通道的激活、失活、传导和调节 频道号码 Ca通道门控的完整实验图， Ca通道数量的传导和调节是长期目标。 的 用于电压钳的联合吸管-微电极方法 将使用分离的蜗牛神经细胞体的内部灌注， 与细胞贴附膜片钳方法结合， 单一频道 膜片钳方法也将应用于PC-12 细胞进行全细胞电压钳制和研究膜补丁。 将使用指数拟合分析宏观电流。 将使用噪声谱分析微观电流波动， 阻抗图。 单通道开放时间和开放频率 将被衡量。 三种不同方法之间的相关性， 宏观电流、微观波动和单通道开口 将作出具体的模型，激活，失活和传导 将被审查。 功能性钙通道数量的调节 细胞内钙，神经递质，有机钙通道阻滞剂和 还将研究二价阳离子。 这些研究正在扩大 PC-12细胞的几个原因：为了比较的目的，因为 各种结构（内-外，外-外， 细胞附着的）容易研究，并且因为结合研究和其他 目前正在对这种细胞系进行生物化学研究。 钙通道 兴奋和一些重要的细胞功能之间的联系 如收缩和分泌。它们在以下功能中很重要： 神经和肌肉骨骼系统以及内分泌系统， 因此，可能与影响这些疾病的许多疾病有关。 系统.

Calcium channel function will be examined using electrophysiological methods. The present proposal is directed toward specific aspects of activation, inactivation, conduction in open channels and regulation of channel numbers. A complete experimental picture of Ca channel gating and conduction and regulation of Ca channel numbers is the long term goal. The combined suction pipette-microelectrode method for voltage clamp and internal perfusion of isolated snail nerve cell bodies will be used in conjunction with the cell-attached patch clamp method for recording from single channels. The patch clamp method will also be applied to PC-12 cells for whole cell voltage clamping and the study of membrane patches. Macroscopic currents will be analyzed using exponential fitting. Microscopic current fluctuations will be analyzed using noise spectra and impedance plots. The open time and frequency of opening of single channels will be measured. Correlation among the three different approaches, macroscopic currents, microscopic fluctuations and single channel openings will be made and specific models of activation, inactivation and conduction will be examined. Regulation of functional Ca channel numbers by intracellular Ca, neural transmitters, organic Ca channel blockers and divalent cations will also be investigated. The studies are being extended to PC-12 cells for several reasons: for comparative purposes, because membrane patches in a variety of configurations (inside-out, outside-out, cell-attached) are readily studied and because binding studies and other biochemical studies are being done on this cell line. Calcium channels are the link between excitation and a number of important cellular functions such as contraction and secretion. They are important in the function of the nervous and musculoskeletal systems and the endocrine systems and, therefore, may be involved in the numerous diseases that affect these systems.