High sensitivity of immature GABAergic neurons to blockers of voltage-gated calcium channels.

Détails

ID Serval
serval:BIB_8A0FD51204CC
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
High sensitivity of immature GABAergic neurons to blockers of voltage-gated calcium channels.
Périodique
Brain Research. Developmental Brain Research
Auteur(s)
Pardo B., Honegger P.
ISSN
0165-3806 (Print)
ISSN-L
0165-3806
Statut éditorial
Publié
Date de publication
1999
Volume
115
Numéro
1
Pages
9-16
Langue
anglais
Résumé
The involvement of voltage-gated calcium channels in the survival of immature CNS neurons was studied in aggregating brain cell cultures by examining cell type-specific effects of various channel blockers. Nifedipine (10 microM), a specific blocker of L-type calcium channels, caused a pronounced and irreversible decrease of glutamic acid decarboxylase activity, whereas the activity of choline acetyltransferase was significantly less affected. Flunarizine (1-10 microM, a relatively unspecific ion channel blocker) elicited similar effects, that were attenuated by NMDA. The glia-specific marker enzymes, glutamine synthetase and 2',3'-cyclic nucleotide 3'-phosphohydrolase, were affected only after treatment with high concentrations of nifedipine (50 microM) or NiCl2 (100 microM, shown to block T-type calcium channels). Nifedipine (50 microM), NiCl2 (100 microM), and flunarizine (5 microM) also caused a significant increase in the soluble nucleosome concentration, indicating increased apoptotic cell death. This effect was prevented by cycloheximide (1 microM). Furthermore, the combined treatment with calcicludine (10 nM, blocking L-type calcium channels) and funnel-web spider toxin-3.3 (100 nM, blocking T-type channels) also caused a significant increase in free nucleosomes as well as a decrease in glutamic acid decarboxylase activity. In contrast, cell viability was not affected by peptide blockers specific for N-, P-, and/or Q-type calcium channels. Highly differentiated cultures showed diminished susceptibility to nifedipine and flunarizine. The present data suggest that the survival of immature neurons, and particularly that of immature GABAergic neurons, requires the sustained entry of Ca2+ through voltage-gated calcium channels.
Mots-clé
Acetylcholine/physiology, Animals, Calcium Channel Blockers/pharmacology, Cell Aging/drug effects, Cell Death/drug effects, Cells, Cultured, Cycloheximide/pharmacology, Flunarizine/pharmacology, Ion Channel Gating, Membrane Potentials/drug effects, Neurons/drug effects, Nifedipine/pharmacology, Rats, Rats, Sprague-Dawley, gamma-Aminobutyric Acid/physiology
Pubmed
Web of science
Création de la notice
24/01/2008 14:12
Dernière modification de la notice
03/03/2018 19:09
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