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001-es BibID:	BIBFORM009112
Első szerző:	Pál Balázs (élettanász)
Cím:	Targets, receptors and effects of muscarinic neuromodulation on giant neurones of the rat dorsal cochlear nucleus / Pal, B., Koszeghy, A., Pap, P., Bakondi, G., Pocsai, K., Szucs, G., Rusznak, Z.
Dátum:	2009
ISSN:	0953-816X
Megjegyzések:	Although cholinergic modulation of the cochlear nucleus (CN) is functionally important, neither its cellular consequences nor the types of receptors conveying it are precisely known. The aim of this work was to characterise the cholinergic effects on giant cells of the CN, using electrophysiology and quantitative polymerase chain reaction. Application of the cholinergic agonist carbachol increased the spontaneous activity of the giant cells; which was partly the consequence of the reduction in a K(+) conductance. This effect was mediated via M4 and M3 receptors. Cholinergic modulation also affected the synaptic transmission targeting the giant cells. Excitatory synaptic currents evoked by the stimulation of the superficial and deep regions of the CN were sensitive to cholinergic modulation: the amplitude of the first postsynaptic current was reduced, and the short-term depression was also altered. These changes were mediated via M3 receptors alone and via the combination of M4, M2 and M3 receptors, when the superficial and deep layers, respectively, were activated. Inhibitory synaptic currents evoked from the superficial layer showed short-term depression, but they were unaffected by carbachol. In contrast, inhibitory currents triggered by the activation of the deep parts exhibited no significant short-term depression, but they were highly sensitive to cholinergic activation, which was mediated via M3 receptors. Our results indicate that pre- and postsynaptic muscarinic receptors mediate cholinergic modulation on giant cells. The present findings shed light on the cellular mechanisms of a tonic cholinergic modulation in the CN, which may become particularly important in evoking contralateral excitatory responses under certain pathological conditions
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban agonist Carbachol CN Cochlear Nucleus dorsal cochlear nucleus Electrophysiology giant Health neurone physiology Polymerase Chain Reaction rat receptor Synaptic Transmission
Megjelenés:	The European Journal of Neuroscience. - 30 : 5 (2009), p. 769-782. -
További szerzők:	Kőszeghy Áron (1983-) (Ph.D hallgató, élettanász) Pap Pál (1981-) (élettanász) Bakondi Gábor (1980-) (élettanász) Pocsai Krisztina (1978-) (élettanász) Szűcs Géza (1948-) (élettanász) Rusznák Zoltán (1965-) (élettanász)
Internet cím:	elektronikus változat DOI
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001-es BibID:	BIBFORM040376
Első szerző:	Rusznák Zoltán (élettanász)
Cím:	The hyperpolarization-activated non-specific cation current (Ih) adjusts the membrane properties, excitability, and activity pattern of the giant cells in the rat dorsal cochlear nucleus / Rusznák Zoltán, Pál Balázs, Kőszeghy Áron, Fu YuHong, Szücs Géza, Paxinos George
Dátum:	2013
ISSN:	0953-816X
Megjegyzések:	Giant cells of the cochlear nucleus are thought to integrate multimodal sensory inputs and participate in monaural sound source localization. Our aim was to explore the significance of a hyperpolarization-activated current in determining the activity of giant neurones in slices prepared from 10 to 14-day-old rats. When subjected to hyperpolarizing stimuli, giant cells produced a 4-(N-ethyl-N-phenylamino)-1,2-dimethyl-6-(methylamino) pyridinium chloride (ZD7288)-sensitive inward current with a reversal potential and half-activation voltage of ?36 and ?88 mV, respectively. Consequently, the current was identified as the hyperpolarization-activated non-specific cationic current (Ih). At the resting membrane potential, 3.5% of the maximum Ih conductance was available. Immunohistochemistry experiments suggested that hyperpolarization-activated, cyclic nucleotide-gated, cation non-selective (HCN)1, HCN2, and HCN4 subunits contribute to the assembly of the functional channels. Inhibition of Ih hyperpolarized the membrane by 6 mV and impeded spontaneous firing. The frequencies of spontaneous inhibitory and excitatory postsynaptic currents reaching the giant cell bodies were reduced but no significant change was observed when evoked postsynaptic currents were recorded. Giant cells are affected by biphasic postsynaptic currents consisting of an excitatory and a subsequent inhibitory component. Inhibition of Ih reduced the frequency of these biphasic events by 65% and increased the decay time constants of the inhibitory component. We conclude that Ih adjusts the resting membrane potential, contributes to spontaneous action potential firing, and may participate in the dendritic integration of the synaptic inputs of the giant neurones. Because its amplitude was higher in young than in adult rats, Ih of the giant cells may be especially important during the postnatal maturation of the auditory system.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban developing auditory system h-current spontaneous activity synaptic transmission ZD7288
Megjelenés:	European Journal Of Neuroscience. - 37 : 6 (2013), p. 876-890. -
További szerzők:	Pál Balázs (1975-) (élettanász) Kőszeghy Áron (1983-) (Ph.D hallgató, élettanász) Fu, YuHong Szűcs Géza (1948-) (élettanász) Paxinos, George
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM039760
035-os BibID:	PMID:12453052
Első szerző:	Szabo Zsolt
Cím:	Ionic currents determining the membrane characteristics of type I spiral ganglion neurons of the guinea pig / Zs. Szabó, Cs. Harasztosi, I. Sziklai, G. Szűcs, Z. Rusznák
Dátum:	2002
ISSN:	0953-816X
Megjegyzések:	Enzymatically isolated type I spiral ganglion neurons of the guinea pig have been investigated in the present study. The identity of the cells was confirmed by using anti-neuron-specific enolase immunostaining. The presence and shredding of the myelin sheath was also documented by employing anti-S100 immunoreaction. The membrane characteristics of the cells were studied by using the whole-cell patch-clamp technique. The whole-cell capacitance of the cells was 9 +/- 2 pF (n = 51), while the resting membrane potential of the cells was -62 +/- 9 mV (n = 19). When suprathreshold depolarizing stimuli were applied, the neurons fired a single action potential at the beginning of the stimulation. It was confirmed in this study that type I spiral ganglion cells possess a hyperpolarization-activated nonspecific cationic current (Ih). The major characteristics of this current component were unaffected by the enzyme treatment. Type I spiral ganglion cells also expressed various depolarization-activated K+ current components. A high-threshold outward current was sensitive to 1-10 mm TEA+ application. The ganglion cells also expressed a relatively small, but nevertheless present, transient outward current component which was less sensitive to TEA+ but could be inhibited by 100 micro m 4-aminopyridine. A DTX-I-sensitive current was responsible for some 30% of the total outward current (at 0 mV), showed rapid activation at membrane potentials positive to -50 mV and demonstrated very little inactivation. However, inhibition of the highly 4-AP- or DTX-I-sensitive component did not alter the rapidly inactivating nature of the firing pattern of the cells.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban egyetemen (Magyarországon) készült közlemény
Megjelenés:	European Journal of Neuroscience. - 16 : 10 (2002), p. 1887-1895. -
További szerzők:	Harasztosi Csaba Sziklai István (1954-) (fül-orr-gégész) Szűcs Géza (1948-) (élettanász) Rusznák Zoltán (1965-) (élettanász)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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