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Titolo:
THE EFFECT OF INTRACELLULAR CA2-ACTIVATED CURRENTS IN CEREBELLAR GRANULE CELLS IN CULTURE( ON GABA)
Autore:
MARTINA M; KILIC G; CHERUBINI E;
Indirizzi:
SCUOLA INT SUPER STUDI AVANZATI,BIOFIS LAB,VIA BEIRUT 2-4 I-34014 TRIESTE ITALY
Titolo Testata:
The Journal of membrane biology
fascicolo: 2, volume: 142, anno: 1994,
pagine: 209 - 216
SICI:
0022-2631(1994)142:2<209:TEOICC>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
RAT CENTRAL NEURONS; HIPPOCAMPAL-NEURONS; RECEPTOR FUNCTION; AMINO-ACIDS; CALCIUM; MODULATION; CHANNELS; RELEASE; CA-2+; PHOSPHORYLATION;
Keywords:
PATCH CLAMP; GABA(A) RECEPTOR; FURA-2; INTRACELLULAR CA2+; RAT CEREBELLUM; A23187;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
30
Recensione:
Indirizzi per estratti:
Citazione:
M. Martina et al., "THE EFFECT OF INTRACELLULAR CA2-ACTIVATED CURRENTS IN CEREBELLAR GRANULE CELLS IN CULTURE( ON GABA)", The Journal of membrane biology, 142(2), 1994, pp. 209-216

Abstract

The patch clamp technique was used to study the effects of intracellular free calcium ([Ca2+](i)) on GABA(A)-evoked whole-cell and single channel currents of cultured cerebellar granule cells. Changes in [Ca2+](i) were obtained by adding to the extracellular solution the calciumionophore A23187 (2 mu M). The relationship between [Ca2+](i) and [Ca2+](o) in the presence or absence of A23187 was assessed using fluorimetric measurements from Fura-2 loaded cells. In 2 mM [Ca2+](o) and A23187, [Ca2+]i was about 1.5 mu M, whereas in the absence of A23187 it was about 250 nM. In whole-cell experiments (symmetrical chloride concentrations) at -50 mV, GABA (0.5 mu M) evoked inward currents that did not desensitize. Bath application of A23187 significantly reduced the steady-state amplitude of GABA currents by 37 +/- 6%. Single channel currents activated by GABA (0.5 mu M) were also recorded in the outside-out configuration of the patch clamp technique. Kinetic analysis of single channel events revealed that A23187 significantly increased the long closed time constant (tau(c3)) without affecting the open time constants (tau(o1) and tau(o2)) or the short and medium closed time constants (tau(c1) and tau(c2)). Moreover, application of A23187 induced asignificant reduction of burst duration (tau(b)). We conclude that a rise in [Ca2+](i) by A23187 may decrease the binding affinity of GABA for the GABA(A) receptor.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/07/20 alle ore 05:23:31