title: Distribution of AMPA receptor subunits and TARPs in synaptic and extrasynaptic membranes of the adult rat nucleus accumbens.
abstract: We characterized the distribution of AMPA receptor (AMPAR) subunits and the transmembrane AMPA receptor regulatory proteins (TARPs) γ-2 and γ-4 in adult rat nucleus accumbens (NAc) using a method that separates plasma membranes into synaptic membrane-enriched and extrasynaptic membrane-enriched fractions. We also measured GluA1 phosphorylated at serine 845 (pS845 GluA1) and serine 831 (pS831 GluA1). GluA1-3 protein levels and pS831 GluA1/total GluA1 were higher in synaptic membranes. However, pS845 GluA1/total GluA1 was higher in extrasynaptic membranes, consistent with a role for S845 phosphorylation in GluA1 insertion at extrasynaptic sites. Homeric GluA1 receptors were detected in extrasynaptic membranes, consistent with evidence for extrasynaptic Ca(2+)-permeable AMPARs in other systems. The TARP γ-2 was enriched in synaptic membranes, whereas γ-4 was mainly found in extrasynaptic membranes, suggesting distinct roles for these proteins in the NAc. These experiments provide fundamental information that will aid in the interpretation of studies on AMPAR-related plasticity in the NAc.
authors.affiliation: Department of Neuroscience, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064 3095, United States. ferrario@umich.edu
authors.forename: Carrie R
authors.initials: CR
authors.lastname: Ferrario
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Loweth
authors.forename: Mike
authors.initials: M
authors.lastname: Milovanovic
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Wang
authors.forename: Marina E
authors.initials: ME
authors.lastname: Wolf
mesh_terms: D000818:Animals; D047468:Immunoprecipitation / Q000379:methods; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000166:cytology*; D021122:Protein Subunits / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D013569:Synapses / Q000378:metabolism*; D013570:Synaptic Membranes / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D021122:Protein Subunits; D018091:Receptors, AMPA; D012694:Serine