کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5548770 | 1556594 | 2017 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Mutation of the inhibitory ethanol site in GABAA Ï1 receptors promotes tolerance to ethanol-induced motor incoordination Mutation of the inhibitory ethanol site in GABAA Ï1 receptors promotes tolerance to ethanol-induced motor incoordination](/preview/png/5548770.png)
- Ï1 and Ï1(T6'Y) receptors differ in ethanol but not GABA responses.
- Ï1(T6'Y) knockin mice were generated to test the in vivo role of the ethanol site.
- Ï1 knockin and knockout mice recover faster from ethanol-induced ataxia.
- Ï1 knockin and knockout mice show increased acute functional tolerance.
- Ï1 regulates tolerance to ethanol intoxication, which may increase ethanol abuse.
Genes encoding the Ï1/2 subunits of GABAA receptors have been associated with alcohol (ethanol) dependence in humans, and Ï1 was also shown to regulate some of the behavioral effects of ethanol in animal models. Ethanol inhibits GABA-mediated responses in wild-type (WT) Ï1, but not Ï1(T6'Y) mutant receptors expressed in Xenopus laevis oocytes, indicating the presence of an inhibitory site for ethanol in the second transmembrane helix. In this study, we found that Ï1(T6'Y) receptors expressed in oocytes display overall normal responses to GABA, the endogenous GABA modulator (zinc), and partial agonists (β-alanine and taurine). We generated Ï1 (T6'Y) knockin (KI) mice using CRISPR/Cas9 to test the behavioral importance of the inhibitory actions of ethanol on this receptor. Both Ï1 KI and knockout (KO) mice showed faster recovery from acute ethanol-induced motor incoordination compared to WT mice. Both KI and KO mutant strains also showed increased tolerance to motor impairment produced by ethanol. The KI mice did not differ from WT mice in other behavioral actions, including ethanol intake and preference, conditioned taste aversion to ethanol, and duration of ethanol-induced loss of righting reflex. WT and KI mice did not differ in levels of Ï1 or Ï2 mRNA in cerebellum or in ethanol clearance. Our findings indicate that the inhibitory site for ethanol in GABAA Ï1 receptors regulates acute functional tolerance to moderate ethanol intoxication. We note that low sensitivity to alcohol intoxication has been linked to risk for development of alcohol dependence in humans.
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Journal: Neuropharmacology - Volume 123, 1 September 2017, Pages 201-209