Discrete Change in Volatile Anesthetic Sensitivity in Mice with Inactivated Tandem Pore Potassium Ion Channel TRESK

Background We investigated the role of tandem pore potassium ion channel (K-2P) TRESK in neurobehavioral function and volatile anesthetic sensitivity in genetically modified mice Methods Exon III of the mouse TRESK gene locus was deleted by homologous recombination using a targeting vector The genotype of bred mice (wild type knockout or heterozygote) was determined using polymerase chain reaction Morphologic and behavioral evaluations of TRESK knockout mice were compared with wild-type littermates Sensitivity of bred mice to isoflurane halothane sevoflurane and desflurane were studied by determining the minimum alveolar concentration preventing movement to nil clamping in 50% of each genotype Results With the exception of decreased number of inactive periods and Increased thermal pain sensitivity (20% decrease in latency with hot plate test) TRESK knockout mice had healthy development and behavior TRESK knockout mice showed a statistically significant 8% increase in isoflurane minimum alveolar concentration compared with wild-type littermates Sensitivity to other volatile anesthetics was not significantly different Spontaneous mortality of TRESK knockout mice after initial anesthesia testing was nearly threefold higher than that of wild-type littermates Conclusions TRESK alone is not critical for baseline central nervous system function but may contribute to the action of volatile anesthetics The inhomogeneous change in anesthetic sensitivity corroborates findings in other K-2P knockout mice and supports the theory that the mechanism of volatile anesthetic action involves multiple targets Although it was not shown in this study, a compensatory effect by other K-2P channels may also contribute to these observations