Transgenic expression of a mutant glycine receptor decreases alcohol sensitivity of mice.
Glycine receptors (GlyRs) are pentameric ligand-gated ion channels that inhibit neurotransmission in the adult brainstem and spinal cord. GlyR function is potentiated by ethanol in vitro, and a mutant GlyR subunit alpha(1)(S267Q) is insensitive to the potentiating effects of ethanol. To test the importance of GlyR for the actions of ethanol in vivo, we constructed transgenic mice with this mutation. Under the control of synapsin I regulatory sequences, transgenic expression of S267Q mutant GlyR alpha(1) subunits in the nervous system was demonstrated using [(3)H]strychnine binding and immunoblotting. These mice showed decreased sensitivity to ethanol in three behavioral tests: ethanol inhibition of strychnine seizures, motor incoordination (rotarod), and loss of righting reflex. There was no change in ethanol sensitivity in tests of acute functional tolerance or body temperature, and there was no change in ethanol metabolism. Transgene effects were pharmacologically specific for ethanol, compared with pentobarbital, flurazepam, and ketamine. These results support the idea that glycine receptors contribute to some behavioral actions of ethanol and that ethanol sensitivity can be changed in vivo by transgenic expression of a single receptor subunit.
Findlay
G S
GS
Waggoner Center for Alcohol and Addiction Research, Section of Neurobiology, University of Texas at Austin, 78712, USA. gfind@mail.utexas.edu
Wick
M J
MJ
Mascia
M P
MP
Wallace
D
D
Miller
G W
GW
Harris
R A
RA
Blednov
Y A
YA
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001831:Body Temperature / Q000187:drug effects; D002492:Central Nervous System Depressants / Q000493:pharmacokinetics / Q000494:pharmacology*; D017931:DNA Primers; D000431:Ethanol / Q000493:pharmacokinetics / Q000494:pharmacology*; D005998:Glycine / Q000494:pharmacology; D018684:Glycine Agents / Q000378:metabolism; D015151:Immunoblotting; D018782:Maze Learning / Q000187:drug effects; D051379:Mice; D008822:Mice, Transgenic; D009043:Motor Activity / Q000187:drug effects; D009154:Mutation / Q000235:genetics*; D009865:Oocytes / Q000187:drug effects; D018408:Patch-Clamp Techniques; D010641:Phenotype; D004856:Postural Balance / Q000187:drug effects; D018009:Receptors, Glycine / Q000096:biosynthesis* / Q000235:genetics*; D012640:Seizures / Q000235:genetics; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology; D013331:Strychnine / Q000378:metabolism; D014981:Xenopus
D002492:Central Nervous System Depressants; D017931:DNA Primers; D018684:Glycine Agents; D018009:Receptors, Glycine; D000431:Ethanol; D013331:Strychnine; D005998:Glycine