Membrane and cellular actions of anesthetic agents.

It is generally accepted that anesthetics affect most biological cells in a nonspecific fashion. A similar or unitary mechanism of action has been proposed for all anesthetics. This may be the rule for general anesthesia; however, evidence exists which suggests that all anesthetics may not act via the same mechanism or at the same site. It is well recognized that various anesthetic agents can affect peripheral systems in a selective manner that is often clinically relevant. In addition to the nonspecific requirement of lipid solubility, specific molecular structure may determine the selectivity of an anesthetic and thus its pattern of anesthesia. Recent studies on an isolated neuronal preparation, the stretch receptor of the crayfish, are presented which demonstrate that anesthetics can differentially alter neuronal behavior in addition to producing biphasic effects of excitation and depression. It is yet to be resolved whether these effects are relevant to the mechanism of anesthesia.