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Titolo:
Theta-frequency facilitation of AMPA receptor-mediated synaptic currents in the principal cells of the medial septum
Autore:
Armstrong, JN; MacVicar, BA;
Indirizzi:
Univ Calgary, Fac Med, Dept Physiol & Biophys, Neurosci Res Grp, Calgary, AB T2N 4N1, Canada Univ Calgary Calgary AB Canada T2N 4N1 s Grp, Calgary, AB T2N 4N1, Canada
Titolo Testata:
JOURNAL OF NEUROPHYSIOLOGY
fascicolo: 4, volume: 85, anno: 2001,
pagine: 1709 - 1718
SICI:
0022-3077(200104)85:4<1709:TFOARS>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
FIMBRIA-FORNIX LESIONS; GLUTAMATE-RECEPTOR; CA2+ PERMEABILITY; SELECTIVE ANTAGONISM; CHANNEL PROPERTIES; CEREBRAL-CORTEX; BASAL FOREBRAIN; NMDA RECEPTORS; CALCIUM-ENTRY; NEURONS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: MacVicar, BA Univ Calgary, Fac Med, Dept Physiol & Biophys, Neurosci Res Grp, 3330 HospDr NW, Calgary, AB T2N 4N1, Canada Univ Calgary 3330 Hosp Dr NW Calgary AB Canada T2N 4N1 Canada
Citazione:
J.N. Armstrong e B.A. MacVicar, "Theta-frequency facilitation of AMPA receptor-mediated synaptic currents in the principal cells of the medial septum", J NEUROPHYS, 85(4), 2001, pp. 1709-1718

Abstract

Recent evidence suggests that Ca2+-permeable AMPA receptors display rapid,short-lasting current facilitation. In this study, we investigated the properties of AMPA receptor-mediated synaptic currents in medial septal neurons of the rat in an in vitro slice preparation. Immunocytochemistry with a selective antibody to the GluR2 subunit revealed that both choline acetyltransferase-containing and parvalbumin-containing neurons of the medial septumexpress no detectable GluR2 subunit immunoreactivity. We used whole cell voltage-clamp recordings to measure synaptically evoked AMPA receptor-mediated currents from medial septal neurons following stimulation of midline afferents. The GYKI 52466 (50 muM)- and 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[ f]quinoxaline-7-sulfonamide (NBQX) (20 muM)-sensitive AMPA receptor-mediated component of the synaptic response was isolated by blocking GABA(A) - and N-methyl-D-aspartate receptor-mediated currents with 30 muM bicuculline and 100 muM 2-amino-5-phosphonovaleric acid, respectively. In some cases, patched cells were filled with Lucifer yellow (0.1%) and imaged using 2-photon laser scanning microscopy. AMPA receptor-mediated currents that were observed in large medial septal neurons (20-30 mum) displayed rectification. These currents were sensitive to external application of philanthotoxin-343 (PhTx-343, 50 muM), a potent, high-affinity antagonist of Ca2+-permeable, GluR2-lacking AMPA receptors. Rectifying AMPA receptor-mediated currents also displayed a rapid increase in amplitude when evoked five times at low frequency such as 6 Hz. In contrast to currents observed in large medial septal neurons, AMPA-receptor mediated currents evoked in the remaining small(8-11 mum) neurons were nonrectifying and displayed rapid synaptic depression when stimulated five times at 6 Hz. The currents evoked in these cells were unaffected by external application of PhTx-343 and were therefore GluR2-containing AMPA receptors. The results of the present study demonstrate that the principal projection neurons of the medial septum contain PhTx-343-sensitive, GluR2-lacking AMPA receptors that display rapid current facilitation when stimulated at low frequencies.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 08/04/20 alle ore 07:38:52