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 ?Bungarotoxin, ligands for ?3- and ?7-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 ?3, ?2, and ?4 subunits. Immunocytochemistry showed that the percentage of ?3-, ?2-, and ?4- but not of ?7-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 ?3 subunit is associated with the ?2 and/or ?4 subunits. Conversely, dystrophin is not involved in the stabilization of the ?7-containing nAChRs, as the percentage of ?7-immunopositive synapses is similar in both wild-type and mdx mouse SCG. © 2002 Elsevier Science (USA).
Dystrophin stabilizes ?3- but not ?7-containing nicotinic acetylcholine receptor subtypes at the postsynaptic apparatus in the mouse superior cervical ganglion
Gotti Cecilia;
2002
Abstract
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 ?Bungarotoxin, ligands for ?3- and ?7-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 ?3, ?2, and ?4 subunits. Immunocytochemistry showed that the percentage of ?3-, ?2-, and ?4- but not of ?7-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 ?3 subunit is associated with the ?2 and/or ?4 subunits. Conversely, dystrophin is not involved in the stabilization of the ?7-containing nAChRs, as the percentage of ?7-immunopositive synapses is similar in both wild-type and mdx mouse SCG. © 2002 Elsevier Science (USA).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
