Properties of single ion channel currents elicited by a pulse of agonist concentration or voltage
Properties of single ion channel currents elicited by a pulse of agonist concentration or voltage
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DOI：
10.1098/rsta.1997.0090
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发表时间：
1997-09-15
期刊：
影响因子：
5
通讯作者：
Edmonds, B
中科院分区：
文献类型：
--
作者：
Colquhoun, D;Hawkes, AG;Edmonds, B
通常进行实验以研究单个离子通道响应于由影响其平衡位置的变量的阶跃变化（“跳跃”）产生的扰动的行为，例如电压跳跃或激动剂浓度的跳跃。它也是常见的应用矩形脉冲（由一个跳，然后由一个关跳），例如简短的浓度脉冲被用来模仿突触transmission.Suppose一般马尔可夫机制的通道动力学，我们得到的理论概率分布的可观察到的特性，描述非平稳行为的单离子通道受到跳跃，或脉冲的有限持续时间。这些特征是诸如打开时间、关闭时间、第一延迟、突发长度和激活长度之类的东西。我们特别集中在跳跃到或从零水平的激动剂，这需要一些修改通常的参数，以科普有一些吸收集的状态。在可能的情况下，我们包括的结果，使津贴的现象的时间间隔遗漏，从而可能会错过一些短的时间间隔，由于不完善的决议的记录方法。最后给出了一个数值算例。
Experiments are often performed to study the behaviour of a single ion channel in response to a perturbation produced by a step change ('jump') in a variable that influences its equilibrium position, for example a voltage jump or jump in agonist concentration. It is also common to apply a rectangular pulse (consisting of an on jump followed by an off jump); for example brief concentration pulses are used to mimic synaptic transmission.Assuming a general Markov mechanism for channel dynamics, we obtain theoretical probability distributions of observable characteristics that describe the nonstationary behaviour of single ion channels which are subject to a jump, or to a pulse of finite duration. These characteristics are such things as open times, shut times, first latency, burst length and length of activation. We concentrate particularly on jumps to or from a zero level of agonist, which necessitates some modification to the usual arguments to cope with having some absorbing sets of states. Where possible, we include results which make allowance for the phenomenon of time interval omission, whereby some short intervals may be missed due to imperfect resolution of the recording method. A numerical example is studied in detail.