Jpn. J. Pharmacol. 74 (2), 165-169(1997)

Furosemide-Sensitive Calcium Rise Induced by GABAA-Receptor Stimulation in Cultures of Embryonic Rat Striatal Neurons

Yuri Ikeda, Nobuyoshi Nishiyama, Hiroshi Saito and Hiroshi Katsuki (*)

Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan
(*) To whom correspondence should be addressed.

Abstract: 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+/2CI- 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+/2CI- 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.

Keywords: gamma-Aminobutyric acid (GABA), Striatal neuron, Intracellular calcium, Chloride transport, Development

Copyrightę The Japanese Pharmacological Society 1997

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