Bhattacharjee Arin, Kaczmarek Leonard K
Department of Pharmacology and Toxicology, School of Medicine and Biomedical Science, The State University of New York, Buffalo, NY 14214, USA.
Trends Neurosci. 2005 Aug;28(8):422-8. doi: 10.1016/j.tins.2005.06.003.
Although K+ channels activated by Ca2+ have long been known to shape neuronal excitability, evidence is accumulating that K+ channels sensitive to intracellular Na+, termed K(Na) channels, have an equally significant role. K(Na) channels contribute to adaptation of firing rate and to slow afterhyperpolarizations that follow repetitive firing. In certain neurons, they also appear to be activated by Na+ influx accompanying a single spike. Two genes encoding these channels, Slick and Slack, are expressed throughout the brain. The spatial localization of K(Na) channels along axons, dendrites and somata appears to be highly cell-type specific. Their molecular properties also suggest that these channels contribute to the response of neurons to hypoxia.
尽管长期以来人们都知道由Ca2+激活的K+通道可塑造神经元兴奋性，但越来越多的证据表明，对细胞内Na+敏感的K+通道（称为K(Na)通道）也具有同样重要的作用。K(Na)通道有助于调节放电频率，并在重复放电后产生缓慢的超极化。在某些神经元中，它们似乎也可被单个动作电位伴随的Na+内流激活。编码这些通道的两个基因Slick和Slack在全脑均有表达。K(Na)通道沿轴突、树突和胞体的空间定位似乎具有高度的细胞类型特异性。它们的分子特性还表明，这些通道有助于神经元对缺氧的反应。
