Pharmacological And Immunochemical Characterization Of Î±2 Nicotinic Acetylcholine Receptors (Nachrs) In Mouse Brain
Aim: Î±2 nAChR subunit mRNA expression in mice is most intense in the olfactory bulbs and interpeduncular nucleus. We aimed to investigate the properties of Î±2* nAChRs in these mouse brain regions. Methods: Î±2 nAChR subunit-null mutant mice were engineered. Pharmacological and immunoprecipitation studies were used to determine the composition of Î±2 subunit-containing (Î±2) nAChRs in these two regions. Results: [ 125 I]Epibatidine (200 pmol/L) autoradiography and saturation binding demonstrated that Î±2 deletion reduces nAChR expression in both olfactory bulbs and interpeduncular nucleus (by 4.81.7 and 9226 fmolmg -1 protein, respectively). Pharmacological characterization using the Î’2-selective drug A85380 to inhibit [ 125 I]epibatidine binding proved inconclusive, so immunoprecipitation methods were used to further characterize Î±2 nAChRs. Protocols were established to immunoprecipitate Î’2 and Î’4 nAChRs. Immunoprecipitation specificity was ascertained using tissue from Î’2- and Î’4-null mutant mice, and efficacy was good (90% of Î’2 and 80% of Î’4 nAChRs were routinely recovered). Conclusion: Immunoprecipitation experiments indicated that interpeduncular nucleus Î±2 nAChRs predominantly contain Î’2 subunits, while those in olfactory bulbs contain mainly Î’4 subunits. In addition, the immunoprecipitation evidence indicated that both nuclei, but especially the interpeduncular nucleus, express nAChR complexes containing both Î’2 and Î’4 subunits. Â© 2009 CPS and SIMM.
Acta Pharmacologica Sinica
Digital Object Identifier (DOI)
Whiteaker, Paul; Wilking, Jennifer A.; Brown, Robert W.B.; Brennan, Robert J.; Collins, Allan C.; Lindstrom, Jon M.; and Boulter, Jim, "Pharmacological And Immunochemical Characterization Of Î±2 Nicotinic Acetylcholine Receptors (Nachrs) In Mouse Brain" (2009). Neurobiology. 393.