title: No evidence of a role of the β4 subunit of the nicotinic acetylcholine receptor in alcohol-related behaviors.
abstract: BACKGROUND
  Nicotinic acetylcholine receptors have gained attention in the last several years as mediators of alcohol-related behaviors. The genes that code for the α5, α3, and β4 subunits (Chrna5, Chrna3, and Chrnb4, respectively) map adjacent to each other on human chromosome 15/mouse chromosome 9. Genetic variants in this region have been associated with alcohol phenotypes and mice that overexpress these three subunits have reduced ethanol intake. In the present experiments, we examined the role of the Chrnb4 gene in three ethanol behaviors: consumption, ataxia, and sedation. Wildtype, heterozygous, and knockout mice were tested for ethanol consumption with a 2-bottle choice procedure and the drinking-in-the-dark paradigm. Ethanol-induced ataxia was measured with the balance beam and dowel test. Finally, the sedative effects of ethanol were measured with the loss of righting reflex paradigm.
  
  
  RESULTS
  We observed no significant genotypic effects on any of the ethanol behaviors examined, suggesting that the β4 subunit is not involved in mediating these responses.
  
  
  CONCLUSIONS
  While we found no evidence for the involvement of the β4 subunit in ethanol responses, it is possible that this subunit modulates other behaviors not tested and further work should address this before completely ruling out its involvement.
authors.affiliation: Department of Biobehavioral Health, Penn State University, University Park, PA, USA. hmk123@psu.edu.|Center for Brain, Behavior, and Cognition, Penn State University, University Park, PA, USA. hmk123@psu.edu.
authors.forename: Helen M
authors.identifier: http://orcid.org/0000-0001-5085-8847
authors.initials: HM
authors.lastname: Kamens
authors.affiliation: Department of Biobehavioral Health, Penn State University, University Park, PA, USA.
authors.forename: Constanza
authors.initials: C
authors.lastname: Silva
authors.affiliation: Department of Integrative Physiology, University of Colorado, Boulder, CO, USA.
authors.forename: Riley
authors.initials: R
authors.lastname: McCarthy
authors.affiliation: Department of Integrative Physiology, University of Colorado, Boulder, CO, USA.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Cox
authors.affiliation: Department of Integrative Physiology, University of Colorado, Boulder, CO, USA.|Institute for Behavioral Genetics, University of Colorado, Boulder, CO, USA.
authors.forename: Marissa A
authors.initials: MA
authors.lastname: Ehringer
mesh_terms: D000367:Age Factors; D000428:Alcohol Drinking / Q000235:genetics / Q000503:physiopathology*; D000704:Analysis of Variance; D000818:Animals; D002755:Choice Behavior / Q000187:drug effects* / Q000502:physiology; D016292:Procedural Sedation; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005838:Genotype; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D011978:Receptors, Nicotinic / Q000235:genetics / Q000502:physiology*
chemical_list: C486720:Chrnb4 protein, mouse; D006993:Hypnotics and Sedatives; D009419:Nerve Tissue Proteins; D011978:Receptors, Nicotinic; D000431:Ethanol
keywords: Ataxia; Chrnb4; Consumption; Ethanol; Nicotinic acetylcholine receptors; Sedation