Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
MULTIPLE ACTIONS OF THE NOVEL ANTICONVULSANT DRUG TOPIRAMATE IN THE RAT SUBICULUM IN-VITRO
Autore:
KAWASAKI H; TANCREDI V; DARCANGELO G; AVOLI M;
Indirizzi:
MCGILL UNIV,MONTREAL NEUROL INST,RES GRP CELL BIOL EXCITABLE TISSUES,3801 UNIV ST MONTREAL PQ H3A 2B4 CANADA MCGILL UNIV,MONTREAL NEUROL INST,RES GRP CELL BIOL EXCITABLE TISSUES MONTREAL PQ H3A 2B4 CANADA MCGILL UNIV,DEPT NEUROL & NEUROSURG MONTREAL PQ H3A 2B4 CANADA MCGILL UNIV,DEPT PHYSIOL MONTREAL PQ H3A 2B4 CANADA UNIV ROMA TOR VERGATA,DIPARTIMENTO NEUROSCI I-00173 ROME ITALY
Titolo Testata:
Brain research
fascicolo: 1-2, volume: 807, anno: 1998,
pagine: 125 - 134
SICI:
0006-8993(1998)807:1-2<125:MAOTNA>2.0.ZU;2-E
Fonte:
ISI
Lingua:
ENG
Soggetto:
BURSTING NEURONS; IN-VITRO; CURRENTS; EPILEPSY;
Keywords:
SUBICULUM; TOPIRAMATE; NA+-ELECTROGENESIS; GABA; RAT;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
22
Recensione:
Indirizzi per estratti:
Citazione:
H. Kawasaki et al., "MULTIPLE ACTIONS OF THE NOVEL ANTICONVULSANT DRUG TOPIRAMATE IN THE RAT SUBICULUM IN-VITRO", Brain research, 807(1-2), 1998, pp. 125-134

Abstract

We used an in vitro slice preparation to study whether and how the anticonvulsant drug topiramate (TPM, 50-500 mu M) modulates the excitability of rat subicular neurons that generate action potential bursts mainly caused by voltage-dependent, Na+-electrogenesis. Subiculum is a gating structure for outputs originating from the hippocampus proper, and thus it may play a role in limbic seizures. In 28/45 neurons, TPM induced a steady hyperpolarization of the resting membrane potential (RMP) that ranged between -2 and -16 mV and was associated with a 24-62%decrease of the apparent membrane input resistance. TPM also depressed the ability of these cells to generate action potential bursts in response to brief (5-150 ms) depolarizing pulses, such an effect was characterized by an increase in the amount of intracellular depolarizing current required for eliciting action potential bursts, and it also occurred when the TPM-induced steady hyperpolarization was compensated by injecting steady depolarizing current. In addition TPM reduced by approx. 50% the regular action potential firing elicited by prolonged (350-1000 ms) depolarizing pulses (n = 15 of 27 neurons). Recovery of the TPM-induced changes was not seen during washout for periods of 20-80min (n = 7). Both the steady hyperpolarization of the RMP and the input resistance decrease elicited by TPM were markedly reduced by the GABA(A) receptor antagonists bicuculline methiodide (10 mu M; n = 6) or picrotoxin (100 mu M; n = 2); such an effect was associated with a reduction, but not with blockade of the depressant action exerted by TPM on burst generation. Our findings indicate that TPM reduces subicular cell excitability, and modifies bursting ability and repetitive firingproperties. These effects may be ascribed to actions on voltage-gated, Na+ electrogenesis and GABA(A) receptors. We propose that these changes in excitability may all contribute to the anticonvulsant action ofTPM in limbic seizures that occur in temporal lobe epilepsy patients. (C) 1998 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/01/20 alle ore 20:41:17