Voltage-Gated Ion Channels and Electrical Excitability

Our ability to do gymnastics, to perceive a colorful world, and to process language relies on rapid communication among neurons. Such signaling, the fastest in our bodies, involves electrical messages produced as ion channels in cell membranes open and close. Various ion channels mediate sensory transduction, electrical “computations,” propagation over long distances, and synaptic transmission. Here, we focus on voltage-gated ion channels, the family of channels that includes the familiar Na+, K+, and Ca2+ channels of nerve and muscle excitability. In the computer metaphor of the brain, the voltage-gated ion channels are like the transistors of logical circuits, detecting, amplifying, and reshaping electrical messages. Our basic understanding of these proteins maintains the framework and rigor established 50 years ago by Hodgkin and Huxley 1952, enriched by much new molecular information and by insights gained from patch-clamp methods.