title: Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor subunit expression in rat olfactory bulb.
abstract: The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors (AMPARs) mediate rapid responses at most central excitatory synapses, including those in the olfactory bulb (OB). These receptors are composed of the glutamate subunits GluR1-4, which each has two splice variant (flip/flop) forms. We recently showed that AMPARs on OB neurons are kinetically and pharmacologically diverse. Here, we explored whether this functional heterogeneity reflects a diverse expression of AMPAR subunits and/or splice variants. Total RNA from rat OBs was amplified by RT-PCR. Digestion of the panGluR PCR product with subunit-specific restriction enzymes revealed that the OB expresses mRNAs for GluR1-4 but in different relative amounts i.e., GluR2 (61 +/- 2.4%), GluR1 (31 +/- 3.5%), GluR4 (6.3 +/- 1.4%), GluR3 (1.4 +/- 0.7%). Furthermore, GluR2 and GluR4 transcripts were composed of similar amounts of flip and flop, whereas GluR1 and GluR3 transcripts consisted mostly of flip. If similar to other brain regions, this heterogeneity in patterns of expression may facilitate information processing.
authors.affiliation: Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL 32306-4340, USA.
authors.forename: Michelle S
authors.initials: MS
authors.lastname: Horning
authors.forename: Bumsup
authors.initials: B
authors.lastname: Kwon
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Blakemore
authors.forename: Corinne M
authors.initials: CM
authors.lastname: Spencer
authors.forename: Marion
authors.initials: M
authors.lastname: Goltz
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Houpt
authors.forename: Paul Q
authors.initials: PQ
authors.lastname: Trombley
mesh_terms: D000818:Animals; D017931:DNA Primers; D004594:Electrophysiology; D009812:Odorants; D009830:Olfactory Bulb / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D018091:Receptors, AMPA / Q000096:biosynthesis* / Q000235:genetics; D017470:Receptors, Glutamate / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013569:Synapses / Q000378:metabolism
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D018091:Receptors, AMPA; D017470:Receptors, Glutamate