Regulation of neuronal cell volume: from activation to inhibition to degeneration.
Regulation of neuronal cell volume: from activation to inhibition to degeneration.
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神经元细胞体积的调节：从激活到抑制再到退化。
DOI：
10.1113/jphysiol.2010.197251
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Toney,GlennM
中科院分区：
文献类型：
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作者：
Toney,GlennM
自从单细胞原生动物出现以来，动物们在面对内外环境组成的频繁变化时，依然能够存活下来，并蓬勃发展。生存的常见挑战之一是细胞体积稳态的紊乱。尽管事实上，进化赋予哺乳动物复杂的系统来调节水和溶质的平衡，细胞体积调节的“设定点”的显着偏差仍然可以发生。人们只需要考虑基本的细胞过程，如胞内和胞吐，就可以理解细胞体积的变化通常是细胞功能的正常部分。诸如能量耗尽、缺氧/缺血和酸中毒的条件导致细胞积聚水分并膨胀。在细胞凋亡的过程中，细胞最初会失去水分并萎缩，然后在死亡前膨胀。神经元可能比其他细胞更容易受到体积变化的影响。这是因为跨质膜的离子梯度对于建立水的渗透分布和正常的电兴奋性都是至关重要的。随着神经元的膨胀和收缩，细胞内体积的变化会导致离子和其他信号分子浓度的相应变化。因为大脑被安置在坚硬的头盖骨中，细胞的膨胀和收缩将改变细胞外液的体积，从而改变神经元和相邻细胞类型之间的空间关系，影响突触释放的神经递质的浓度和扩散动力学。幸运的是，神经元（像大多数体细胞一样）已经发展出复杂的机制来积极保护它们的体积。当它们膨胀时，例如暴露在
Since the emergence of single-celled protozoans, animals have survived and flourished in the face of frequent changes in the composition of their internal and external environments. Among the common challenges to survival is the disturbance of cell volume homeostasis. Despite the fact that evolution has endowed mammals with complex systems to regulate water and solute balance, significant deviations of the cell volume regulatory ‘set-point’can still occur. One need only consider fundamental cellular processes such as endo-and exocytosis to appreciate that cell volume changes are often a normal part of cellular function. Conditions such as energy depletion, hypoxia/ischaemia and acidosis cause cells to accumulate water and swell. During the progression of apoptosis, cells initially lose water and shrink, and then they swell before dying.Neurons are perhaps more vulnerable than other cells to changes in volume. This is because ionic gradients across the plasma membrane are critical for establishing both the osmotic distribution of water and normal electrical excitability. Changes of intracellular volume as neurons swell and shrink produce corresponding changes in the concentration of ions and other signalling molecules. Because the brain is housed in a rigid cranium, swelling and shrinking of cells will change the extracellular fluid volume and thus the spatial relationship between neurons and adjacent cell types, affecting both the concentration and diffusion kinetics of synaptically released neurotransmitters. Fortunately, neurons (like most somatic cells) have developed complex mechanisms to actively defend their volume. When they swell, for example by exposure to