VOLTAGE-DEPENDENT CALCIUM CONDUCTANCES IN MAMMALIAN NEURONS - THE P CHANNEL
VOLTAGE-DEPENDENT CALCIUM CONDUCTANCES IN MAMMALIAN NEURONS - THE P CHANNEL
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DOI：
10.1111/j.1749-6632.1989.tb24084.x
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发表时间：
1989-06-26
影响因子：
5.2
通讯作者：
CHERKSEY, B
中科院分区：
文献类型：
--
作者：
LLINAS, RR;SUGIMORI, M;CHERKSEY, B
钙在哺乳动物中枢神经元的电生理学中发挥着几个关键作用。作为电荷载体，它能够产生动作电位或分级电压响应。“作为第二信使，钙参与递质释放等事件：离子通道的激活（例如，钙依赖性钾电导”）和分子磷酸化，从而调节离子电导。在这里，我们计划简要回顾哺乳动物大脑神经元中电压依赖性钙电导的一些方面，特别强调哺乳动物大脑树突中存在的电导。小脑浦肯野细胞。在详细描述浦肯野细胞的电压依赖性通道特性之前，我们将概括性地回顾一下哺乳动物神经元中遇到的主要钙依赖性电响应性。脊椎动物中枢神经系统（CNS）神经元中钙依赖性尖峰的首次描述是通过直接记录鸟类小脑浦肯野细胞树突而获得的5，后来在乳头神经元中得到了证实。 6 多个电压依赖性钙电导的存在最初是在劣质橄榄中遇到的 (10)。这些细胞表现出两种类型的反应，即高阈值尖峰和低阈值尖峰（分别为 HTS 和 LTS）。“因为在不同类型的中枢神经元的细胞内记录中观察到的最常见的电反应性属于这些类别，”我们将继续如上所述描述它们。相比之下，负责低阈值钙电导的单一通道首先由 Carbone 和 Lux 描述？后来钙通道被分为三类：（a）T通道，我们现在认为对应于低阈值钙电导；（b）N通道，在一定程度上对应于高阈值钙电导；（c）L钙通道，它似乎在中枢神经系统中并不常见，但也属于高阈值钙电导这一类。将我们的命名法简单地纳入提出的框架中上面的“”可能会被证明是有问题的，因为这两个特征的标准是如此不同。单通道标准基于直接测量，不考虑电缆特性。我们的系统是从神经元整合的角度开发的，它考虑了诸如神经元的空间位置等参数。
Calcium plays several critical roles in the electrophysiology of mammalian central neurons. As a charge carrier, it is capable of generating either action potentials or graded voltage responses.'As a second messenger, calcium is involved in such events as transmitter release: the activation of ionic channels (eg, the calcium-dependent potassium conductance'), and the phosphorylation of molecules, which in turn modulate ionic conductances.'Here we plan to review briefly some aspects of the voltagedependent calcium conductance in the neurons of the mammalian brain with particular emphasis on the conductance present in dendrites of cerebellar Purkinje cells. Before describing in detail the voltage-dependent channel properties of Purkinje cells, we will review in general terms the main calcium-dependent electroresponsiveness encountered in mammalian neurons. The first description of calcium-dependent spikes in vertebrate central nervous system (CNS) neurons was obtained by direct recordings from avian cerebellar Purkinje cell dendrites5 This was later confirmed in mammilary neurons. 6 The existence of more than one voltage-dependent calcium conductance was originally encountered in the inferior olive (10). These cells demonstrated two types of responses, the high-and the low-threshold spikes (HTS and LTS, respectively).'.'Because the most common electroresponsiveness observed in intracellular recordings from different types of central neurons fall into these categories,'we will continue to describe them as stated above.By contrast the single channel responsible for the low-threshold calcium conductance was first described by Carbone and Lux? Later the calcium channels were grouped into three categories":(a) the T channels, which we now believe correspond to the low-threshold calcium conductance;(b) the N channels, which correspond to a certain extent to the high-threshold calcium conductance; and (c) the L calcium channel, which does not seem to be very commonly represented in the CNS, but which would also fall into this category of high-threshold calcium conductance. A simple incorporation of our nomenclature into the framework proposed above"'may prove to be problematic because the criteria for these two characterizations are so different. The single-channel criteria are based on direct measurements and do not consider cable properties. Ours was developed from the standpoint of neuronal integration, which takes into account parameters such as the spatial location of the