IONIC MOVEMENTS ACROSS NERVE CELL BODY MEMBRANES

使用电生理学方法检查钙通道功能 方法：研究方法。本提案针对以下具体方面 开放通道的激活、失活、传导及调控 频道号。一张完整的钙通道门控实验图片和 钙通道数目的传导和调节是长期的目标。这个 吸移管-微电极结合的电压钳制方法 分离的蜗牛神经细胞体的内部灌流将用于 结合细胞附着式膜片钳方法记录来自 单通道。膜片钳方法也将应用于PC-12 用于全电池电压钳制和膜贴片研究的电池。 宏观电流将使用指数拟合进行分析。 微观电流波动将使用噪声频谱和 阻抗曲线图。单通道开通时间和频率 将会被测量。三种不同方法之间的相关性， 宏观电流、微观涨落与单通道开度 将制作和具体的激活、失活和传导模式 将会被检查。功能钙通道数的调节 细胞内钙，神经递质，有机钙通道阻滞剂和 二价阳离子也将被研究。这些研究正在被延长 有几个原因：为了比较的目的，因为 各种形状的膜贴片(由内而外，由外而外， 细胞附着)很容易被研究，而且因为结合研究和其他 目前正在对该细胞系进行生化研究。钙通道是 兴奋与许多重要的细胞功能之间的联系 比如收缩和分泌。它们在功能上是很重要的 神经和肌肉骨骼系统以及内分泌系统， 因此，可能参与了许多影响这些疾病的疾病 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.