Electrophysiology of Myxicola Giant Axons

离子通过被称为离子通道的大蛋白质分子中充满水的微观孔隙穿过细胞膜。这些通道的特点是它们对特定离子的选择性、打开和关闭门控的模式以及阻断它们的药剂的性质。本项目的重点是了解无脊椎动物模型系统（海洋蠕虫Myxicola infundbulum的巨大轴突）中电压激活的NA+通道和电压激活的K+通道的通道门控的分子机制。除了使用特定的药物来分离和探测离子通道的功能外，还使用了三种不同的电生理技术：(1)通过高分辨率的传统电压钳记录平方毫米；(2)检查膜内电荷运动产生的小的“门控电流”，这种电流显然会开启离子通道；(3)用玻璃微移液管（称为“膜片钳”）隔离轴突膜的几平方微米，研究单个离子通道的打开和关闭。要充分了解离子的分子作用，需要同时应用所有这些技术，因为每种技术产生的信息不同。实验结果将与理论分析相结合，建立一个详细的、可测试的离子通道功能模型。

Ions move across cell membranes through microscopic water-filled pores in large protein molecules referred to as ion channels. Such channels are characterized by their selectivity for a particular ion, mode of opening and closing - gating, and by the nature of agents that block them. This project focuses on understanding the molecular mechanisms underlying channel gating in an invertebrate model system, the giant axon from the marine worm Myxicola infundibulum, for both voltage-activated NA+ channels and voltage-activated K+ channels. In addition to using specific drugs to separate and probe ion channels function, three different electrophysiological techniques are used: (1) recording square millimeters by high-resolution, conventional voltage- clamp; (2) examining intramembrane charge movements producing the small "gating currents" that apparently initiate opening of ion channels; and (3) investigating the opening and closing of single ion channels by isolating a few square microns of the axon membrane with a glass micropipette - called "patch clamp". A full understanding of the molecular operation of ion requires the simultaneous application of all these techniques because each yields different information. Experimental results will combine with theoretical analysis to develop a detailed, testable model of ion channel function.