Anesthetic mechanisms in-vitro and in general anesthesia

1. There is no generally accepted and quantifiable definition of general anesthesia. 2. Ion channels are discussed as examples of in-vitro systems used to investigate anesthetic mechanisms. Experimental evidence has accumulated demonstrating that voltage-gated ion channels and ligand-gated ion channels may be affected by clinically relevant concentrations of general anesthetics. 3. There are many factors modulating the anesthetic sensitivity of ion channels, including membrane lipid, electrolyte environment, ion channel subtype, and the functional state of the network. 4. Neuronal networks relevant to human general anesthesia have to be identified before criteria can be formulated as to which component of any particular ion channel function has to be altered to what extent in order to make a contribution to clinical anesthesia.