title: Altered sedative effects of ethanol in mice with α1 glycine receptor subunits that are insensitive to Gβγ modulation.
abstract: Alcohol abuse and alcoholism are major health problems and one of the leading preventable causes of death. Before achieving better treatments for alcoholism, it is necessary to understand the critical actions of alcohol on membrane proteins that regulate fundamental functions in the central nervous system. After generating a genetically modified knock-in (KI) mouse having a glycine receptor (GlyR) with phenotypical silent mutations at KK385/386AA, we studied its cellular and in vivo ethanol sensitivity. Analyses with western blotting and immunocytochemistry indicated that the expression of α1 GlyRs in nervous tissues and spinal cord neurons (SCNs) were similar between WT and KI mice. The analysis of synaptic currents recorded from KI mice showed that the glycinergic synaptic transmission had normal properties, but the sensitivity to ethanol was significantly reduced. Furthermore, the glycine-evoked current in SCNs from KI was resistant to ethanol and G-protein activation by GTP-γ-S. In behavioral studies, KI mice did not display the foot-clasping behavior upon lifting by the tail and lacked an enhanced startle reflex response that are characteristic of other glycine KI mouse lines with markedly impaired glycine receptor function. The most notable characteristic of the KI mice was their significant lower sensitivity to ethanol (∼40%), expressed by shorter times in loss of righting reflex (LORR) in response to a sedative dose of ethanol (3.5 g/Kg). These data provide the first evidence to link a molecular site in the GlyR with the sedative effects produced by intoxicating doses of ethanol.
authors.affiliation: Laboratory of Neurophysiology, Department of Physiology, University of Concepcion, Concepcion, Chile.
authors.forename: Luis G
authors.initials: LG
authors.lastname: Aguayo
authors.affiliation: Laboratory of Neurophysiology, Department of Physiology, University of Concepcion, Concepcion, Chile.
authors.forename: Patricio
authors.initials: P
authors.lastname: Castro
authors.affiliation: Laboratory of Neurophysiology, Department of Physiology, University of Concepcion, Concepcion, Chile.
authors.forename: Trinidad
authors.initials: T
authors.lastname: Mariqueo
authors.affiliation: Laboratory of Neurophysiology, Department of Physiology, University of Concepcion, Concepcion, Chile.
authors.forename: Braulio
authors.initials: B
authors.lastname: Muñoz
authors.affiliation: Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.affiliation: Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Lovinger
authors.affiliation: Departments of Anesthesiology and Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Gregg E
authors.identifier: 0000000336418153
authors.initials: GE
authors.lastname: Homanics
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001933:Brain Stem / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D055879:Gene Knock-In Techniques; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009154:Mutation; D018408:Patch-Clamp Techniques; D018009:Receptors, Glycine / Q000235:genetics / Q000378:metabolism*; D013216:Reflex, Startle / Q000502:physiology; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
chemical_list: D006993:Hypnotics and Sedatives; D018009:Receptors, Glycine; D000431:Ethanol