CCL

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1.

001-es BibID:BIBFORM040494
Első szerző:Dallos Péter
Cím:Acetylcholine, outer hair cell electromotility, and the cochlear amplifier / Peter Dallos, David Z. Z. He, Xi Lin, István Sziklai, Samir Mehta, Burt N. Evans
Dátum:1997
Megjegyzések:The dominant efferent innervation of the cochlea terminates on outer hair cells (OHCs), with acetylcholine (ACh) being its principal neurotransmitter. OHCs respond with a somatic shape change to alterations in their membrane potential, and this electromotile response is believed to provide mechanical feedback to the basilar membrane. We examine the effects of ACh on electromotile responses in isolated OHCs and attempt to deduce the mechanism of ACh action. Axial electromotile amplitude and cell compliance increase in the presence of the ligand. This response occurs with a significantly greater latency than membrane current and potential changes attributable to ACh and is contemporaneous with Ca2+ release from intracellular stores. It is likely that increased axial compliance largely accounts for the increase in motility. The mechanical responses are probably related to a recently demonstrated slow efferent effect. The implications of the present findings related to commonly assumed efferent behavior in vivo are considered.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
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Megjelenés:Journal of Neuroscience. - 17 : 6 (1997), p. 2212-2226. -
További szerzők:He, David Z. Z. Lin, Xi Mehta, Shamir Evans, Burt N. Sziklai István (1954-) (fül-orr-gégész)
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM040491
035-os BibID:PMID:8793511
Első szerző:Sziklai István (fül-orr-gégész)
Cím:Effect of acetylcholine and GABA on the transfer function of electromotility in isolated outer hair cells / István Sziklai, David Z.Z. He, Peter Dallos
Dátum:1996
ISSN:0378-5955
Megjegyzések:Outer hair cells (OHC) from high- and low-frequency regions were separately isolated from guinea pig cochleas. The cells were inserted with their ciliary pole first into a partitioning microchamber so that only 20-50% of the cell length was excluded. Somatic length changes due to transcellular electrical stimulation were measured at the cuticular plate in the inserted portion of the cells. Transfer curves of electromotility of the OHCs were obtained by both a series of brief (2.5 ms) and longer (30 ms) square pulses with opposite polarity and linearly increasing size from 40 to 280 mV in both negative and positive directions. Alterations in the transient and steady-state electromotility transfer curves were examined by application of acetylcholine (ACh) and gamma-aminobutyric acid (GABA) to the synaptic pole. ACh, in the concentration range of 10-30 microM, evoked a significant magnitude and gain increase of electromotility in both transient and steady-state responses without a measurable shift in the operating point of the displacement-voltage transfer curve. A tonotopic response magnitude difference is found for ACh challenge. Basal turn OHCs responded with greater magnitude increase (+90% increase from control) than apical turn OHCs (+40%). GABA exerted an opposite effect, again in a location-dependent manner. Magnitude response decreased about 30% for long cells and 14% for short ones. Atropin, a muscarinic receptor antagonist, completely blocked the increase in electromotility response due to ACh. However, D-tubocurarine, a nicorinic receptor antagonist, while not blocking the ACh effect, altered the cell's apparent operating point. Bicuculline methiodide, a GABAA-receptor antagonist, completely arrested GABA influences on the electromotility response. These results suggest that both ACh and GABA can change the electromotile activity of OHCs, in a tonotopically biased manner. ACh challenge evokes greater magnitude responses in basal turn OHCs, whereas GABA induces greater motility response decrease in apical turn OHCs. The control of the gain and magnitude of electromotility by the transmitter substances appear to involve at least two mechanisms. One is probably related to conformational changes of the voltage-to-movement converter molecules and a change in their number in an effective operational pool, the other operates via changing the electrical resistance of the basolateral cell membrane.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
külföldön készült közlemény
Megjelenés:Hearing Research. - 95 : 1-2 (1996), p. 87-99. -
További szerzők:He, David Z. Z. Dallos Péter
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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3.

001-es BibID:BIBFORM040085
Első szerző:Sziklai István (fül-orr-gégész)
Cím:Phosphorylation Mediates the Influence of Acetylcholine upon Outer Hair Cell Electromotility / Sziklai, I., Szőnyi, M., Dallos, P.
Dátum:2001
ISSN:0001-6489
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Acta Oto-Laryngologica. - 121 : 2 (2001), p. 153-156. -
További szerzők:Szőnyi Magdolna Dallos Péter
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4.

001-es BibID:BIBFORM040765
Első szerző:Szőnyi Magdolna
Cím:Cyclic GMP and outer hair cell electromotility / Szönyi Magdolna, He David Z. Z., Ribári Ottó, Sziklai István, Dallos Peter
Dátum:1999
ISSN:0378-5955
Megjegyzések:The aim of this study is to examine the effect of phosphorylation pathways on the electrically evoked fast motile response of isolated outer hair cells (OHCs). Transcellular electrical stimulation was applied in the microchamber to guinea pig OHCs and motility was measured before and after drug application. Forskolin (adenylate cyclase activator), phorbol 12-myristate 13-acetate (PMA, protein kinase C activator) and dibutyryl 3',5'-cyclic guanosine monophosphate (cGMP agonist) were studied. As controls, L15 medium and dimethyl-sulfoxide (DMSO) were used. In each group, 12 cells were measured. Forskolin and PMA were dissolved in 0.1% DMSO to render them membrane permeable. DMSO by itself caused a statistically significant electromotility magnitude decrease. Forskolin and PMA could not reverse the motility decrease due to DMSO, the effects seen in their presence were the same as observed with DMSO alone. Thus, neither 3',5'-cyclic AMP-dependent protein kinase nor calcium/phospholipid-dependent protein kinase appear to have modulatory effects on electromotility. Dibutyryl cGMP (DBcGMP), in concentrations of 200 microM, elicited a significant electromotility magnitude increase. The DBcGMP effect could be inhibited by co-application of 200 microM DBcGMP and 100 microM 8-Rp-pCPT-cGMPS (8-4-chlorophenylthio-guanosine 3',5'-cyclic monophosphothioate, Rp isomer, a cGMP antagonist). Our results suggest that OHC electromotility is modulated by a cGMP-dependent pathway.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Hearing Research. - 137 : 1-2 (1999), p. 29-42. -
További szerzők:He, David Z. Z. Ribári Ottó (1932-) (fül-orr-gégész, audiológus) Sziklai István (1954-) (fül-orr-gégész) Dallos Péter
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5.

001-es BibID:BIBFORM040087
Első szerző:Szőnyi Magdolna
Cím:Intracellular calcium and outer hair cell electromotility / Szonyi, M., He, D. Z., Ribari, O., Sziklai, I., Dallos, P.
Dátum:2001
ISSN:0006-8993
Megjegyzések:The influence of increased intracellular calcium level on outer hair cell (OHC) electromotility was examined by means of transcellular electrical stimulation in a partitioning microchamber. Electromotile activity was measured before and after application of the calcium ionophore ionomycin, which promotes the inflow of extracellular calcium, as well as its release from intracellular calcium stores. The ionomycin solvent, dimethyl sulphoxide (DMSO), by itself elicited a significant decrease in the magnitude of OHC electromotility. The DMSO effect was counteracted by 10 microM ionomycin and was reversed by 50 microM ionomycin. The increase in electromotility is partially mediated by a calmodulin-dependent mechanism, since W7, a calmodulin antagonist, attenuated the 50 microM ionomycin-induced motility increase. Our results suggest that the electromotility magnitude increase in isolated OHCs due to ionomycin is a calcium/calmodulin-dependent phenomenon.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Brain Research. - 922 : 1 (2001), p. 65-70. -
További szerzők:He, David Z. Z. Ribári Ottó (1932-) (fül-orr-gégész, audiológus) Sziklai István (1954-) (fül-orr-gégész) Dallos Péter
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6.

001-es BibID:BIBFORM040975
Első szerző:Szűcs Attila (fül-orr-gégész)
Cím:Measurement of caffeine induced ion currents in isolated guinea pig OHCs (P55) / Attila Szűcs, David Z. Z. He, Peter Dallos, István Sziklai
Dátum:2000
Tárgyszavak:Orvostudományok Klinikai orvostudományok előadáskivonat
Megjelenés:37th Workshop Inner Biology / ed. Matti Anniko. - p. 70.
További szerzők:He, David Z. Z. Dallos Péter Sziklai István (1954-) (fül-orr-gégész)
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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