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001-es BibID:	BIBFORM037816
Első szerző:	Kőszeghy Áron (Ph.D hallgató, élettanász)
Cím:	Activation of muscarinic receptors increases the activity of the granule neurones of the rat dorsal cochlear nucleus : a calcium imaging study / Áron Kőszeghy, János Vincze, Zoltán Rusznák, Yuhong Fu, George Paxinos, László Csernoch, Géza Szücs
Dátum:	2012
ISSN:	0031-6768
Megjegyzések:	Acetylcholine modulates the function of the cochlear nucleus via several pathways. In this study the effects of cholinergic stimulation were studied on the cytoplasmic Ca2+ concentration of granule neurones of the rat dorsal cochlear nucleus (DCN). Ca2+ transients were recorded in Oregon-Green-BAPTA 1-loaded brain slices using a calcium imaging technique. For the detection, identification, and characterisation of the Ca2+ transients, a wavelet analysis-based method was developed. Granule cells were identified on the basis of their size and localisation. The action potential-coupled character of the Ca2+ transients of the granule cells was established by recording fluorescence changes and electrical activity simultaneously. Application of the cholinergic agonist carbamyl-choline (CCh) significantly increased the frequency of the Ca2+ transients (from 0.37 to 6.31 min-1, corresponding to a 17.1-fold increase; n = 89). This effect was antagonised by atropine, whereas CCh could still evoke an 8.3-fold increase of the frequency of the Ca2+ transients when hexamethonium was present. Using immunolabelling, the expression of both type 1 and type 3 muscarinic receptors (M1 and M3 receptors, respectively) was demonstrated in the granule cells. Application of 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (an M3-specific antagonist) prevented the onset of the CCh effect, whereas an M1-specific antagonist (pirenzepine) was less effective. We conclude that cholinergic stimulation increases the activity of granule cells, mainly by acting on their M3 receptors. The modulation of the firing activity of the granule cells, in turn, may modify the firing of projection neurones, and may adjust signal processing in the entire DCN.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Pflügers Archiv. - 463 : 6 (2012), p. 829-844. -
További szerzők:	Vincze János (1988-) (orvos) Rusznák Zoltán (1965-) (élettanász) Fu, YuHong Paxinos, George Csernoch László (1961-) (élettanász) Szűcs Géza (1948-) (élettanász)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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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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