Pichon Y, Prime L, Benquet P, Tiaho F
Equipe Canaux et Récepteurs Membranaires, Université de Rennes 1, UMR 6026, Bâtiment 13, Campus de Beaulieu, Avenue du Général Leclerc, 35042 Cedex Rennes, France.
Eur Biophys J. 2004 May;33(3):211-26. doi: 10.1007/s00249-003-0373-0. Epub 2004 Jan 14.
Recent analyses of the genomes of several animal species, including man, have revealed that a large number of ion channels are present in the nervous system. Our understanding of the physiological role of these channels in the nervous system has followed the evolution of biophysical techniques during the last century. The observation and the quantification of the electrical events associated with the operation of the ionic channels has been, and still is, one of the best tools to analyse the various aspects of their contribution to nerve function. For this reason, we have chosen to use electrophysiological recordings to illustrate some of the main functions of these channels. The properties and the roles of Na+ and K+ channels in neuronal resting and action potentials are illustrated in the case of the giant axons of the squid and the cockroach. The nature and role of the calcium currents in the bursting behaviour of the neurons are illustrated for Aplysia giant neurons. The relationship between presynaptic calcium currents and synaptic transmission is shown for the squid giant synapse. The involvement of calcium channels in survival and neurite outgrowth of cultured neurons is exemplified using embryonic cockroach brain neurons. This same neuronal preparation is used to illustrate ion channel noise and single-channel events associated with the binding of agonists to nicotinic receptors. Some features of the synaptic activity in the central nervous system are shown, with examples from the cercal nerve giant-axon preparation of the cockroach. The interplay of different ion conductances involved in the oscillatory behaviour of the Xenopus spinal motoneurons is illustrated and discussed. The last part of this review deals with ionic homeostasis in the brain and the function of glial cells, with examples from Necturus and squids.
最近对包括人类在内的几种动物物种的基因组分析表明，神经系统中存在大量离子通道。上个世纪，我们对这些通道在神经系统中的生理作用的理解随着生物物理技术的发展而不断深入。与离子通道运作相关的电活动的观察和量化一直是且仍然是分析其对神经功能贡献的各个方面的最佳工具之一。因此，我们选择使用电生理记录来说明这些通道的一些主要功能。在鱿鱼和蟑螂的巨大轴突的例子中，阐述了Na+和K+通道在神经元静息电位和动作电位中的特性及作用。对于海兔巨大神经元，说明了钙电流在神经元爆发行为中的性质和作用。对于鱿鱼巨大突触，展示了突触前钙电流与突触传递之间的关系。以胚胎蟑螂脑神经元为例，说明了钙通道在培养神经元的存活和神经突生长中的作用。同样使用这种神经元标本来说明与激动剂与烟碱样受体结合相关的离子通道噪声和单通道事件。以蟑螂尾须神经巨大轴突标本为例，展示了中枢神经系统中突触活动 的一些特征。阐述并讨论了非洲爪蟾脊髓运动神经元振荡行为中不同离子电导的相互作用。本综述的最后一部分讨论了大脑中的离子稳态和神经胶质细胞的功能，以美西螈和鱿鱼为例。
