AMPA-induced Ca(2+) influx in cultured rat cortical nonpyramidal neurones: pharmacological characterization using fura-2 microfluorimetry.
Immunocytochemical and Co(2+) uptake studies revealed that in primary cultures of rat cortical neurones, the majority of neurones are gamma-aminobutyric acid (GABA) immunopositive and can express Ca(2+)-permeable alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors. By fura-2 microfluorimetry, it was shown that the stimulation with the selective agonist (S)-AMPA (0.3-300 microM) induced a concentration-dependent but cell-variable increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) (EC(50) value 7.4 microM) in more than 80% of the medium-sized multipolar neurones studied. The AMPA-induced rise in [Ca(2+)](i) seems to be due to Ca(2+) entry through AMPA receptor channels, because the response was abolished in Ca(2+)-free solution and by AMPA receptor selective antagonists, but was not significantly influenced by cyclopiazonic acid, an inhibitor of the endoplasmatic Ca(2+)-ATPase, by selective N-methyl-D-aspartic acid (NMDA) receptor antagonists, as well as the Na(+) channel blocker tetrodotoxin and the majority of tested Ca(2+) channel blockers. In conclusion, the results indicate that the cerebral cortical neurones in culture represent mostly GABAergic interneurone-like cells and the majority of them possess Ca(2+)-permeable AMPA receptors, important for intracellular signal transduction and neuronal plasticity.
Fischer
Wolfgang
W
Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Härtelstrasse 16-18, D-04107 Leipzig, Germany. fisw@medizin.uni-leipzig.de
Franke
Heike
H
Scheibler
Peter
P
Allgaier
Clemens
C
Illes
Peter
P
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D001569:Benzodiazepines / Q000494:pharmacology; D001581:Benzothiadiazines / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D003035:Cobalt / Q000493:pharmacokinetics; D003981:Diazoxide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005453:Fluorescence; D005470:Fluorometry / Q000379:methods; D016257:Fura-2; D007150:Immunohistochemistry; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000032:analysis
D001581:Benzothiadiazines; D018691:Excitatory Amino Acid Antagonists; D010879:Piperazines; D011810:Quinoxalines; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D001569:Benzodiazepines; C079692:GYKI 53655; D003035:Cobalt; D005680:gamma-Aminobutyric Acid; D016202:N-Methylaspartate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid; D003981:Diazoxide; C004639:cyclothiazide; D002118:Calcium; D016257:Fura-2