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Titolo:
Phosphorylation regulates spontaneous and evoked transmitter release at a giant terminal in the rat auditory brainstem
Autore:
Oleskevich, S; Walmsley, B;
Indirizzi:
Australian Natl Univ, John Curtin Sch Med Res, Div Neurosci, Synapt Struct& Funct Grp, Canberra, ACT 2601, Australia Australian Natl Univ Canberra ACT Australia 2601 rra, ACT 2601, Australia
Titolo Testata:
JOURNAL OF PHYSIOLOGY-LONDON
fascicolo: 2, volume: 526, anno: 2000,
pagine: 349 - 357
SICI:
0022-3751(20000715)526:2<349:PRSAET>2.0.ZU;2-V
Fonte:
ISI
Lingua:
ENG
Soggetto:
PROTEIN-KINASE-C; ANTEROVENTRAL COCHLEAR NUCLEUS; EXCITATORY POSTSYNAPTIC CURRENTS; HIPPOCAMPAL PYRAMIDAL CELLS; SYNAPTIC VESICLE PROTEINS; PHORBOL ESTERS; BUSHY CELLS; NEUROTRANSMITTER RELEASE; SYNAPSIN-I; TRANSMISSION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Oleskevich, S Australian Natl Univ, John Curtin Sch Med Res, Div Neurosci,Synapt Struct& Funct Grp, POB 334, Canberra, ACT 2601, Australia Australian Natl Univ POB 334 Canberra ACT Australia 2601 lia
Citazione:
S. Oleskevich e B. Walmsley, "Phosphorylation regulates spontaneous and evoked transmitter release at a giant terminal in the rat auditory brainstem", J PHYSL LON, 526(2), 2000, pp. 349-357

Abstract

1. The role of phosphorylation in synaptic transmission was investigated at a large glutamatergic terminal, the endbulb of Held, on bushy cells in the rat anteroventral cochlear nucleus (AVCN).2. Whole-cell recordings of excitatory postsynaptic currents (EPSCs) were used to examine the effects of kinase inhibitors and activators on low-frequency (baseline) evoked release, spontaneous release, paired-pulse facilitation (PPF) or depression (PPD), repetitive stimuli and recovery from depression.3. Application of the kinase inhibitor H7 (100 mu M) reduced low-frequencyevoked EPSC amplitude (by 15 %) and simultaneously increased PPF (or reduced PPD), with no significant change in other aspects of transmission. H7 did not affect the amplitude or frequency of spontaneous miniature EPSCs.4. Phorbol eaters increased EPSC amplitude (by 50 %) with a concomitant decrease in PPF (or increase in PPD), and reduced the final EPSC amplitude during repetitive stimuli. The effect of phorbol esters was due exclusively to protein kinase C (PKC) activation, as the specific PKC inhibitor bis-indolylmaleimide (Bis) completely blocked the potentiating effect of phorbol esters on EPSC amplitude.5. Significantly, phorbol esters did not increase the evoked EPSC amplitude at connections in which release was maximized using high extracellular calcium concentrations (4-6 mM).6. Phorbol esters increased the frequency of spontaneous miniature EPSCs in physiological calcium (by 275 %), and in high extracellular calcium (by 210 %) when phorbol eaters did not increase the evoked EPSC amplitude.7. Our results are most consistent with the actions of H7 to decrease levy-frequency release probability and phorbol esters to increase law-frequencyrelease probability at the endbulb-busy cell synaptic connection in the AVCN. The effects of H7 and phorbol esters on paired-pulse responses and tetanic depression appear to be largely consequential to these changes in low-frequency release probability.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 13/08/20 alle ore 13:04:57