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Titolo:
Muscarinic receptor activation induces depolarizing plateau potentials in bursting neurons of the rat subiculum
Autore:
Kawasaki, H; Palmieri, C; Avoli, M;
Indirizzi:
McGill Univ, Montreal Neurol Inst, Montreal, PQ H3A 2B4, Canada McGill Univ Montreal PQ Canada H3A 2B4 Inst, Montreal, PQ H3A 2B4, Canada McGill Univ, Dept Neurol, Montreal, PQ H3A 2B4, Canada McGill Univ Montreal PQ Canada H3A 2B4 urol, Montreal, PQ H3A 2B4, Canada McGill Univ, Dept Neurosurg, Montreal, PQ H3A 2B4, Canada McGill Univ Montreal PQ Canada H3A 2B4 surg, Montreal, PQ H3A 2B4, Canada McGill Univ, Dept Physiol, Montreal, PQ H3A 2B4, Canada McGill Univ Montreal PQ Canada H3A 2B4 siol, Montreal, PQ H3A 2B4, Canada Univ Milan, Osped San Paolo, Ctr Epilessia, I-20142 Milan, Italy Univ Milan Milan Italy I-20142 aolo, Ctr Epilessia, I-20142 Milan, Italy
Titolo Testata:
JOURNAL OF NEUROPHYSIOLOGY
fascicolo: 5, volume: 82, anno: 1999,
pagine: 2590 - 2601
SICI:
0022-3077(199911)82:5<2590:MRAIDP>2.0.ZU;2-K
Fonte:
ISI
Lingua:
ENG
Soggetto:
VOLTAGE-CLAMP ANALYSIS; LAYER-II NEURONS; IN-VITRO; HIPPOCAMPAL-NEURONS; SLOW AFTERDEPOLARIZATION; ENTORHINAL CORTEX; CHOLINERGIC MECHANISMS; PYRAMIDAL NEURONS; IONIC MECHANISMS; PILOCARPINE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Avoli, M 3801 Univ St, Montreal, PQ H3A 2B4, Canada 3801 Univ St MontrealPQ Canada H3A 2B4 real, PQ H3A 2B4, Canada
Citazione:
H. Kawasaki et al., "Muscarinic receptor activation induces depolarizing plateau potentials in bursting neurons of the rat subiculum", J NEUROPHYS, 82(5), 1999, pp. 2590-2601

Abstract

Muscarinic receptor activation induces depolarizing plateau potentials in bursting neurons of the rat subiculum. J. Neurophysiol. 82: 2590-2601, 1999. Acetylcholine functions as a neuromodulator in the mammalian brain by binding to specific receptors and thus bringing about profound changes in neuronal excitability. Activation of muscarinic receptors often results in an increased excitability of cortical cells. It is, however, unknown whether such an action is present in the subiculum, a limbic structure that may be involved in cognitive processes as well as in seizure propagation. Most rat subicular neurons are endowed of intrinsic membrane properties that make them fire action potential bursts. Using intracellular recordings from these bursting cells in a slice preparation, we report here that application of the cholinergic agonist carbachol (CCh, 30-100 mu M) to medium containing ionotropic excitatory amino acid receptor antagonists reduces burst-afterhyperpolarizations (burst-AHPs) and discloses depolarizing plateau potentials that outlast the triggering current pulses by 140-2,800 ms. These plateau potentials appear with CCh concentrations >50 mu M and are dependent on the resting membrane potential and on the intensity/duration of the triggering pulse; are recorded during application of tetrodotoxin (1 mu M, n = 5 neurons); but are markedly reduced by replacing 82% of extracellular Na+ with equimolar choline (n = 6). Plateau potentials also are abolished by Co2+ (2 mM;n = 5) or Cd2+ (1 mM; n = 2) application and by recording with electrodes containing the Ca2+ chelator bis(2-aminophenoxy)ethane-N, N,N',N'-tetraacetic acid (0.2 M; n = 6). CCh-induced burst-AHP reduction and plateau potentials are reversed by the muscarinic antagonist atropine (0.5 mu M, n = 7). In conclusion, our findings demonstrate a powerful muscarinic modulation of the intrinsic excitability of subicular bursting cells that is predominatedby the appearance of plateau potentials. These changes in excitability maycontribute to physiological processes such as learning or memory and play a role in the generation of epileptiform depolarizations. We propose that, as in other limbic structures, muscarinic plateau potentials in the subiculum are mainly due to a Ca2+-dependent nonselective cationic conductance.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 21/09/20 alle ore 15:55:24