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Titolo:
Synchronisation of neurotransmitter release during postnatal development in a calyceal presynaptic terminal of rat
Autore:
Chuhma, N; Koyano, K; Ohmori, H;
Indirizzi:
Kyoto Univ, Fac Med, Dept Physiol, Kyoto 6068501, Japan Kyoto Univ KyotoJapan 6068501 c Med, Dept Physiol, Kyoto 6068501, Japan
Titolo Testata:
JOURNAL OF PHYSIOLOGY-LONDON
fascicolo: 1, volume: 530, anno: 2001,
pagine: 93 - 104
SICI:
0022-3751(20010101)530:1<93:SONRDP>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
AUDITORY BRAIN-STEM; SUPERIOR OLIVARY COMPLEX; CALCIUM-CHANNEL TYPES; TRANSMITTER RELEASE; SYNAPTIC TRANSMISSION; MEDIAL NUCLEUS; TRAPEZOID BODY; GLUTAMATE RECEPTORS; COCHLEAR NUCLEUS; CALYX SYNAPSE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
41
Recensione:
Indirizzi per estratti:
Indirizzo: Ohmori, H Kyoto Univ, Fac Med, Dept Physiol, Kyoto 6068501, Japan Kyoto Univ Kyoto Japan 6068501 t Physiol, Kyoto 6068501, Japan
Citazione:
N. Chuhma et al., "Synchronisation of neurotransmitter release during postnatal development in a calyceal presynaptic terminal of rat", J PHYSL LON, 530(1), 2001, pp. 93-104

Abstract

1. Mechanisms contributing to the synchronisation of transmitter release during development were studied in synapses of the medial nucleus of the trapezoid body (MNTB) using patch recording and Ca2+ imaging techniques in a rat brainstem slice preparation.2. Excitatory postsynaptic currents (EPSCs) were generated in an all-or-none manner at immature synapses (postnatal days earlier than P6). Many delayed miniature EPSC (mEPSC)-like currents followed EPSCs at immature synapses, while observations of delayed mEPSC-like currents were rare at mature synapses (later than P9).3. At immature synapses bath application of either omega -conotoxin GVIA or omega -agatoxin-IVA reduced EPSCs (both to 40% of control), and Ca2+ currents in the presynaptic terminal (both to 70% of control). The frequency ofdelayed mEPSC-like currents was reduced by w-conotoxin GVIA, but not by omega -agatoxin IVA.4. At immature synapses delayed mEPSC-like currents were rare after incubation of the slice with extrinsic Ca2+ buffers (EGTA AM).5. At mature synapses many mEPSC-like currents followed evoked EPSCs afterpartial block of Ca2+ channels by bath application of a low concentration of Cd2+ (3 muM) or omega -agatoxin IVA (50 nM) but not by low [Ca2+](o) (0.5-1 mM).6. Ca2+ transients induced by action potentials in presynaptic terminals were monitored by adding a high concentration of fura-2 (200 muM) to the pipette. Their decay time course was slower at immature presynaptic terminals than at mature terminals. Both the Ca2+ extrusion rate and the endogenous Ca2+ binding capacity were estimated to be smaller at immature terminals than at mature terminals.7. These results suggest that the maturation of synaptic transmission in MNTB progresses with the capacity for Ca2+ clearance from the presynaptic terminal. The possible importance of developmental increases in both Ca2+ clearance capacity and Ca2+ currents is discussed in relation to the synchronisation of transmitter release.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 23/09/20 alle ore 13:02:43