Stirring up controversy with a voltage sensor paddle.

Neurons owe their exquisite electrical excitability to voltage-gated ion channels. By creating and shaping the action potential, these voltage-sensitive proteins supply the neuron with crucial communication skills. A steady stream of experimental results, arising from numerous laboratories and employing a diverse repertoire of techniques, has produced a consensus model of the way voltage-gated ion channels sense and respond to changes in membrane potential. In contrast to this consensus mechanism, recent studies of the voltage-gated K(+) channel KvAP suggest a strikingly different mode of action. In this review, these disparate models are compared and critically discussed.