Changes in AMPA receptor-spliced variant expression and shift in AMPA receptor spontaneous desensitization pharmacology during cerebellar granule cell maturation in vitro.
Using appropriate internal standards, quantitative reverse transcripase-polymerase chain reaction (RT-PCR), and cerebellar granule cell (CG) in primary cultures we have quantified the expression of mRNAs encoding for GluR1-4 DL-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor subunits during neuronal maturation in vitro. GluR1 is the mRNA that increases during CG maturation; the expression changes of the other GluR mRNAs are minimal and the translation products of these mRNAs change with a similar pattern. During CG maturation, there is an 8- to 10-fold increase in the GluR1 FLOP mRNA and a twofold increase in the expression of FLOP mRNA for GluR4 and GluR4C. The GluR1 FLIP mRNA increases, but by a smaller extent. We found that the GluR2 mRNA is completely edited at its Q/R site during CG maturation. The increase on the expression of GluR1 FLIP and FLOP and of GluR4 FLOP mRNA variants during development is associated with a 10-fold increase in AMPA-mediated Na+ currents and in the increased amplification of this current by 7-chloro-3-methyl-3,4 dihydro-2H-1,2,4 benzothiadiazine S-S-dioxide (IDRA21) or by 6-chloro-3,4 dihydro-3-(2-norbornen-5-yl)-7-sulfamoyl-1,2,4-benzothiadiazine 1,1 dioxide (cyclothiazide [CT]).
Longone
P
P
Department of Psychiatry, University of Illinois College of Medicine, Chicago 60612, USA.
Impagnatiello
F
F
Mienville
J M
JM
Costa
E
E
Guidotti
A
A
D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D001581:Benzothiadiazines / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology* / Q000187:drug effects; D004594:Electrophysiology; D018507:Gene Expression Regulation, Developmental; D007473:Ion Channels / Q000037:antagonists & inhibitors / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009568:Nitrendipine / Q000494:pharmacology; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017393:RNA Editing / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000819:agonists / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
D001581:Benzothiadiazines; D007473:Ion Channels; D020033:Protein Isoforms; D018091:Receptors, AMPA; C091420:IDRA 21; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D009568:Nitrendipine; D012964:Sodium; C004639:cyclothiazide; D002118:Calcium