Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Effect of cyclothiazide on spontaneous miniature excitatory postsynaptic currents in rat hippocampal pyramidal cells
Autore:
Atassi, B; Glavinovic, MI;
Indirizzi:
McGill Univ, Dept Anaesthesia Res, Montreal, PQ H3G 1Y6, Canada McGill Univ Montreal PQ Canada H3G 1Y6 Res, Montreal, PQ H3G 1Y6, Canada McGill Univ, Dept Physiol, Montreal, PQ H3G 1Y6, Canada McGill Univ Montreal PQ Canada H3G 1Y6 siol, Montreal, PQ H3G 1Y6, Canada
Titolo Testata:
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
fascicolo: 3, volume: 437, anno: 1999,
pagine: 471 - 478
SICI:
0031-6768(199902)437:3<471:EOCOSM>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
GLUTAMATE-RECEPTOR CHANNELS; SYNAPTIC CURRENTS; KAINATE RECEPTORS; AMPA RECEPTORS; VISUAL-CORTEX; UNITARY EPSCS; TIME-COURSE; DESENSITIZATION; NEURONS; SLICES;
Keywords:
AMPA receptor channels; amplitude dependence; cyclothiazide; deactivation; desensitization; diffusion; glutamate; hippocampus;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
32
Recensione:
Indirizzi per estratti:
Indirizzo: Glavinovic, MI McGillCanada Dept Anaesthesia Res, 3655 Drummond St, Montreal, PQ H3G 1Y6, McGill Univ 3655 Drummond St Montreal PQ Canada H3G 1Y6 Y6,
Citazione:
B. Atassi e M.I. Glavinovic, "Effect of cyclothiazide on spontaneous miniature excitatory postsynaptic currents in rat hippocampal pyramidal cells", PFLUG ARCH, 437(3), 1999, pp. 471-478

Abstract

Spontaneous miniature excitatory postsynaptic currents (mEPSCs) were recorded from the CA1 region of slices using the whole-cell patch-clamp technique. Cyclothiazide (0.1 mM), a complete blocker of desensitization of (S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) channels, was applied to determine the changes in amplitude and kinetics of mEPSCs occurring with complete suppression of desensitization. The amplitude of mEPSC (A) was not affected significantly by cyclothiazide, but both the rise (tau(r)) and the decay time (tau(d)) were consistently increased (from 2.3 to 6.5ms and from 9.9 to 22.2 ms respectively). The amplitude dependence of bothtau(d) and tau(r) became much greater, but there was no upward shift of the best-fitting lines. The slopes of the control best-fitting lines were (+/-SD; ms/pA; n=5) 0.39+/-0.05 for tau(d):A and 0.12+/-0.07 for tau(r):A, but, in the presence of cyclothiazide, the corresponding slopes were much steeper (2.1+/-0.60 and 0.68+/-0.21; holding potential was -50 mV and temperature 32 degrees C). These changes, which were slow to develop, suggest that cyclothiazide blocks AMPA receptor channel desensitization, whilst having noeffect on the closing rate of AMPA channels. Judging by the extent of change, the speed of diffusion of glutamate in the synaptic cleft is probably similar to that in water. In conclusion, this study provides evidence that: (1) under control conditions, desensitization of AMPA channels plays a major role in shaping the time course of synaptic currents in CA1; and (2) cyclothiazide prolongs their time course solely by abolishing desensitization.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/07/20 alle ore 10:13:05