Purpose: It is now generally accepted that proteins are the primary targets of general anesthetics. However, the demonstration that the activity of a protein is altered by general anesthetics at clinically relevant concentrations in vitro does not provide direct evidence that this target mediates pharmacological actions of general anesthetics. Here we report on advances that have been made in identifying the contribution of individual ligand-gated ion channels to defined anesthetic endpoints using molecular mouse genetics.
Principal findings: Gamma-aminobutyric acid (GABA)(A) receptor subtypes defined by the presence of the α1, α4, α5, β2, and β3 subunits and two-pore domain potassium channels (TASK-1, TASK-3, and TREK) have been discovered to mediate, at least in part, the hypnotic, immobilizing or amnestic actions of intravenous and volatile general anesthetics. Moreover, using tissues from genetically modified mice, specific functions of GABA(A) receptor subtypes in cortical and spinal neuronal networks were identified.
Conclusion: Genetically modified mice have been very useful for research on mechanisms of anesthesia and have contributed to the functional identification of general anesthetic targets and of the role of these targets in neuronal networks.