Dystrophin Stabilizes α3- But Not α7-Containing Nicotinic Acetylcholine Receptor Subtypes at the Postsynaptic Apparatus in the Mouse Superior Cervical Ganglion

• Published in: Neurobiology of disease 2002-06, Vol.10 (1), p.54-66
• Main Authors: Del Signore, Arianna, Gotti, Cecilia, De Stefano, M.Egle, Moretti, Milena, Paggi, Paola
• Format: Article
• Language: English
• Subjects: dystrophin-dystroglycan complex; epibatidine; genetically dystrophic mdx mice; immunoelectron microscopy; neuronal nicotinic acetylcholine receptor subtypes; subunit-specific antibodies; αbungarotoxin
• ISSN: 0969-9961; 1095-953X
• DOI: 10.1006/nbdi.2002.0495

The nicotinic acetylcholine receptor (nAChR) subtypes were characterized in the superior cervical ganglion (SCG) of wild-type and dystrophin-lacking mdx mice. The binding of Epibatidine and αBungarotoxin, ligands for α3- and α7-containing receptors, respectively, revealed, for each ligand, a single class of high-affinity binding sites, with similar affinity in both wild-type and mdx mice. The Epibatidine-labeled receptors were immunoprecipitated by antibodies against the α3, β2, and β4 subunits. Immunocytochemistry showed that the percentage of α3-, β2-, and β4- but not of α7-immunopositive postsynaptic specializations was significantly lower in mdx than in wild-type mouse SCG. These observations suggest that the mouse SCG contains nAChRs, stabilized by dystrophin, in which the α3 subunit is associated with the β2 and/or β4 subunits. Conversely, dystrophin is not involved in the stabilization of the α7-containing nAChRs, as the percentage of α7-immunopositive synapses is similar in both wild-type and mdx mouse SCG.