NEUROPHARMACOLOGY AND TOXICOLOGYThe GABA-A β3 subunit mediates anaesthesia induced by etomidateO'Meara, Gillian F.; Newman, Richard J.; Fradley, Rosa L.; Dawson, Gerard R.; Reynolds, David S.CACAAuthor Information Merck Sharp & Dohme Research Laboratories, The Neuroscience Research Centre, Terlings Park, Harlow, Essex CM20 2QR, UK CACorresponding author: firstname.lastname@example.org Received 19 April 2004; accepted 17 May 2004 NeuroReport: July 19th, 2004 - Volume 15 - Issue 10 - p 1653-1656 doi: 10.1097/01.wnr.0000134842.56131.fe Buy Metrics Abstract The i.v. agent etomidate exerts its anaesthetic actions through potentiation of γ-aminobutyric acid-A receptors containing β2 and β3 subunits. It was recently shown that the β2 subunit contributes to the sedative properties of etomidate, whereas the β3 subunit is responsible for its anaesthetic properties. However, these studies evaluated anaesthetic effects in point mutation mice in which the effect of etomidate was decreased, but not abolished, at the β2 subunit. Here we have used β2 knockout mice to completely remove any contribution of the β2 subunit to the effects of etomidate. Etomidate was equally anaesthetic in wildtype and knockout mice, thus further confirming that efficacy at the β3 subunit only is sufficient to induce general anaesthesia. © 2004 Lippincott Williams & Wilkins, Inc.