Furosemide-sensitive calcium rise induced by GABAA-receptor stimulation in cultures of embryonic rat striatal neurons.
Changes in [Ca2+]i induced by gamma-aminobutyric acid (GABA) were investigated in primary cultured neurons obtained from fetal rat striatum. GABA and muscimol induced [Ca2+]i rise, and bicuculline blocked the effect of GABA. The [Ca2+]i elevating effect of GABA was also abolished by removal of extracellular Ca2+ or by application of nicardipine. Furthermore, furosemide, an inhibitor of Na+/K+/ 2Cl- co-transport, reversibly inhibited the GABA-induced [Ca2+]i rise. These results suggest that due to the elevated level of intracellular Cl- maintained by Na+/K+/2Cl- transport activity in these neurons, opening of GABAA-receptor-associated Cl- channels results in Cl- efflux, leading to membrane depolarization and activation of L-type voltage-dependent Ca2+ channels.
Ikeda
Y
Y
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Nishiyama
N
N
Saito
H
H
Katsuki
H
H
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology*; D058785:GABA-A Receptor Agonists; D066298:In Vitro Techniques; D009118:Muscimol / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009529:Nicardipine / Q000494:pharmacology; D051381:Rats; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D058785:GABA-A Receptor Agonists; D011963:Receptors, GABA-A; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D005665:Furosemide; D009529:Nicardipine; D002118:Calcium; D001640:Bicuculline