标题： L型钙电流的定量方面 显示英文标题

标题： Quantitative aspects of L-type calcium currents

摘要： 钙电流在神经元和肌细胞中被归类为5种类型，其中4种（L、N、P/Q和R）被认为具有高阈值，而另一种（T）被指定为低阈值。 本综述关注L型电流的定量方面。 L型通道现在根据其结构被区分为四种主要亚型1.1-1.4。 L型钙电流在细胞动态过程中起着许多基本作用，包括神经元和心肌细胞中的起搏作用，以及与突触可塑性相关的转录因子的激活和免疫细胞中的作用。 L型电流的半激活电位已被赋予低至-50 mV和高达接近0 mV的值。 I_L的失活已被发现既与电压（VDI）有关，也与钙有关（CDI），后者成分可能涉及钙诱导的钙释放。 CDI通常是细胞电生理学动态模型中的一个重要方面。 我们描述了建模I_L的基本组件，包括激活以及电压和钙依赖的失活，以及确定电流的两种主要方法。 我们通过来自超过65项代表性研究的数值表格，回顾了过去25年中在各种神经系统和心肌细胞的确定性建模中发现或使用的与I_L相关的动态特性的各种细节。 获得了与激活和失活相关的几个参数的分布和统计信息。 对于生理钙离子浓度下的L型钙电流动力学，可靠的实验数据很少。 神经元大致分为两组，根据实验测得的半激活电位。 显示英文摘要

摘要： Calcium currents in neurons and muscle cells have been classified as being one of 5 types of which four, L, N, P/Q and R were said to be high threshold and one, T, was designated low threshold. This review focuses on quantitative aspects of L-type currents. L-type channels are now distinguished according to their structure as one of four main subtypes 1.1-1.4. L-type calcium currents play many fundamental roles in cellular dynamical processes including pacemaking in neurons and cardiac cells, the activation of transcription factors involved in synaptic plasticity and in immune cells. The half-activation potentials of L-type currents have been ascribed values as low as -50 mV and as high as near 0 mV. The inactivation of I_L has been found to be both voltage (VDI) and calcium-dependent (CDI) and the latter component may involve calcium-induced calcium release. CDI is often an important aspect of dynamical models of cell electrophysiology. We describe the basic components in modeling I_L including activation and both voltage and calcium dependent inactivation and the two main approaches to determining the current. We review, by means of tables of values from over 65 representative studies, the various details of the dynamical properties associated with I_L that have been found experimentally or employed in the last 25 years in deterministic modeling in various nervous system and cardiac cells. Distributions and statistics of several parameters related to activation and inactivation are obtained. There are few reliable experimental data on L-type calcium current kinetics for cells at physiological calcium ion concentrations. Neurons are divided approximately into two groups with experimental half-activation potentials.