Electrophysiology for anesthesiologists

Action potentials are generated by neurons based on simple electrophysiologic principles. These include the interaction of ionic species present at different concentrations across a semipermeable membrane which have different EMFs and voltage-dependent time-variant conductances. The ability to generate action potentials may be altered by medications, such as local or general anesthetics, or physical environment, such as mechanical stimuli or temperature changes. In order to monitor the integrity of electrically excitable tissue, one has to be able to measure electrical potentials. This article reviews understanding the basic properties of the signals generated.