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Titolo:
Choline and selective antagonists identify two subtypes of nicotinic acetylcholine receptors that modulate GABA release from CA1 interneurons in rat hippocampal slices
Autore:
Alkondon, M; Pereira, EFR; Eisenberg, HM; Albuquerque, EX;
Indirizzi:
Univ1Maryland, Sch Med, Dept Pharmacol & Expt Therapeut, Baltimore, MD 2120 Univ Maryland Baltimore MD USA 21201 & Expt Therapeut, Baltimore, MD 2120 Univ Maryland, Sch Med, Dept Neurosurg, Baltimore, MD 21201 USA Univ Maryland Baltimore MD USA 21201 t Neurosurg, Baltimore, MD 21201 USA UnivoFed Rio de Janeiro, CCS, ICB, Dept Farmacol Basica & Clin, BR-21944 Ri Univ Fed Rio de Janeiro Rio De Janeiro Brazil BR-21944 Clin, BR-21944 Ri
Titolo Testata:
JOURNAL OF NEUROSCIENCE
fascicolo: 7, volume: 19, anno: 1999,
pagine: 2693 - 2705
SICI:
0270-6474(19990401)19:7<2693:CASAIT>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
SYNAPTIC TRANSMISSION; PYRAMIDAL CELLS; ACH RECEPTORS; NEURONS; DIVERSITY; CURRENTS; ACTIVATION; NUCLEUS; BRAIN;
Keywords:
hippocampus; GABA; choline; methyllycaconitine; alpha-bungarotoxin; dihydro-beta-erythroidine;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Albuquerque, EX Univ,Maryland, Sch Med, Dept Pharmacol & Expt Therapeut, 655 W Baltimore St Univ Maryland 655 W Baltimore St Baltimore MD USA 21201 St
Citazione:
M. Alkondon et al., "Choline and selective antagonists identify two subtypes of nicotinic acetylcholine receptors that modulate GABA release from CA1 interneurons in rat hippocampal slices", J NEUROSC, 19(7), 1999, pp. 2693-2705

Abstract

Neuronal nicotinic receptors (nAChR) are known to control transmitter release in the CNS. Thus, this study was aimed at exploring the diversity and localization of nAChRs present in CA1 interneurons in rat hippocampal slices. The use of a U-tube as the agonist delivery system was critical for the reliable detection of nicotinic responses induced by brief exposure of the neurons to ACh or to the alpha 7 nAChR-selective agonist choline. The present study demonstrated that CA1 interneurons, in addition to expressing functional alpha 7 nAChRs, also express functional alpha 4 beta 2-like nAChRs and that activation of both receptors facilitates an action potential-dependent release of GABA. Depending on the experimental condition, one of the following nicotinic responses was recorded from the interneurons by means of the patch-damp technique: a nicotinic whole-cell current, depolarization accompanied by action potentials, or GABA-mediated postsynaptic currents (PSCs). Responses mediated by alpha 7 nAChRs were short-lasting, whereas those mediated by alpha 4 beta 2 nAChRs were long-lasting. Thus, phasic or tonic inhibition of CAI interneurons may be achieved by selective activation of alpha 7 or alpha 4 beta 2 nAChRs, respectively. It can also be suggested thatsynaptic levels of choline generated by hydrolysis of ACh in vivo may be sufficient to control the activity of the alpha 7 nAChRs. The finding that methyllycaconitine and dihydro-P-erythroidine (antagonists of alpha 7 and alpha 4 beta 2 nAChRs, respectively) increased the frequency and amplitude ofGABAergic PSCs suggests that there is an intrinsic cholinergic activity that sustains a basal level of nAChR activity in these interneurons.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 06/04/20 alle ore 07:49:04