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001-es BibID:	BIBFORM029352
Első szerző:	Birinyi András (anatómus, neurobiológus)
Cím:	Quantitative morphological analysis of the motoneurons innervating muscles involved in tongue movements of the frogRana esculenta / Birinyi András, Székely György, Csapó Krisztina, Matesz Klára
Dátum:	2004
ISSN:	0021-9967
Megjegyzések:	We give an account of an effort to make quantitative morphological distinctions between motoneurons of the frog innervating functionally different groups of muscles involved in the movements of the tongue. The protractor, retractor, and inner muscles of the tongue were considered on the basis of their major action during the prey-catching behavior of the frog. Motoneurons were selectively labeled with cobalt lysin through the nerves of the individual muscles, and dendritic trees of successfully labeled neurons were reconstructed. Each motoneuron was characterized by 15 quantitative morphological parameters describing the size of the soma and dendritic tree and 12 orientation variables related to the shape and orientation of the dendritic field. The variables were subjected to multivariate discriminant analysis to find correlations between form and function of these motoneurons. According to the morphological parameters, the motoneurons were classified into three functionally different groups weighted by the shape of the perikaryon, mean diameter of stem dendrites, and mean length of dendritic segments. The most important orientation variables in the separation of three groups were the ellipses describing the shape of dendritic arborization in the horizontal, frontal, and sagittal planes of the brainstem. These findings indicate that characteristic geometry of the dendritic tree may have a preference for one array of fibers over another.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal Of Comparative Neurology. - 470 : 4 (2004), p. 409-421. -
További szerzők:	Székely György (1926-2017) (neurobiológus) Csapó Krisztina Matesz Klára (1949-) (anatómus, neurobiológus)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM029093
Első szerző:	Birinyi András (anatómus, neurobiológus)
Cím:	Synaptic targets of commissural interneurons in the lumbar spinal cord of neonatal rats / Birinyi A., Viszokay K., Wéber I., Kiehn O., Antal M.
Dátum:	2003
ISSN:	0021-9967
Megjegyzések:	There is strong evidence that commissural interneurons, neurons with axons that extend to the contralateral side of the spinal cord, play an important role in the coordination of left/right alternation during locomotion. In this study we investigated the projections of commissural interneurons to motor neurons and other commissural interneurons on the other side of the spinal cord in neonatal rats. To establish whether there are direct contacts between axons of commissural interneurons and motor neurons, we carried out two series of experiments. In the first experiment we injected biotinylated dextran amine (BDA) into the lateral motor column to retrogradely label commissural interneurons that may have direct projections to motor neurons. Stained neurons were recovered in the ventromedial areas of the contralateral gray matter in substantial numbers. In the second experiment BDA was injected into the ventromedial gray matter on one side of the lumbar spinal cord, whereas motor neurons were simultaneously labeled on the opposite side by applying biocytin onto the ventral roots. BDA injections into the ventromedial gray matter labeled a strong axon bundle that arose from the site of injection, crossed the midline in the ventral commissure, and extensively arborized in the contralateral ventral gray matter. Many of these axons made close appositions with dendrites and somata of motor neurons and also with commissural interneurons retrogradely labeled with BDA. The results suggest that commissural interneurons may establish monosynaptic contacts with motor neurons on the opposite side of the spinal cord. Our findings also indicate that direct reciprocal connections between commissural interneurons on the two sides of the spinal cord may also exist.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok magyar nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal Of Comparative Neurology. - 461 : 4 (2003), p. 429-440. -
További szerzők:	Viszokay Kornél Wéber Ildikó (1972-) (biológus, neurobiológus) Kiehn, Ole Antal Miklós (1951-) (orvos, anatómus)
Pályázati támogatás:	046121 OTKA
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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001-es BibID:	BIBFORM029088
Első szerző:	Birinyi András (anatómus, neurobiológus)
Cím:	Zinc co-localizes with GABA and glycine in synapses in the lamprey spinal cord / Birinyi A., Parker D., Antal M., Shupliakov O.
Dátum:	2001
ISSN:	0021-9967
Megjegyzések:	The presence of zinc in synaptic terminals in the lamprey spinal cord was examined utilizing a modification of the Timm's sulfide silver method and with the fluorescent marker 6-methoxy-8-quinolyl-p-toluenesulfonamide (TSQ). Axons labeled with a Timm's staining method were predominantly located in the lateral region of the dorsal column. This correlated with a maximum of TSQ fluorescence in this region of the spinal cord. Single labeled terminals accumulating Timm reaction product were also found throughout the gray matter and fiber tracts. At the ultrastructural level, zinc was located in a population of synaptic terminals that co-localized gamma-aminobutyric acid (GABA) and glycine. Possible effects of Zn2+ on neuronal activity were examined. In spinobulbar interneurons, which receive GABAergic input in the dorsal column, zinc potentiated responses to GABA application, but it did not affect responses to GABA in motoneurons. Responses in motoneurons to pressure application of glycine were also not affected by Zn2+. Zinc, however, potentiated monosynaptic glycinergic inhibitory postsynaptic potentials (IPSPs) evoked in motoneurons by inhibitory locomotor network interneurons and increased frequency, but not amplitude of spontaneous miniature IPSPs recorded in the presence of tetrodotoxin (TTX), suggesting presynaptic effects. Glutamate responses and the amplitude of monosynaptic excitatory postsynaptic potentials (EPSPs) in motoneurons were reduced by zinc. These effects appeared to be mediated largely postsynaptically through an effect on the N-methyl-D-aspartate (NMDA) component of the glutamatergic input. Our results thus show that free zinc is present in inhibitory synaptic terminals in the lamprey spinal cord, and that it may function as a modulator of inhibitory synaptic transmission.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok magyar nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal Of Comparative Neurology. - 433 : 2 (2001), p. 208-221. -
További szerzők:	Parker, David (1960-) (vegyész) Antal Miklós (1951-) (orvos, anatómus) Shupliakov, Oleg
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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001-es BibID:	BIBFORM053829
Első szerző:	Gustafsson, Jenny S.
Cím:	Ultrastructural organization of lamprey reticulospinal synapses in three dimensions / Jenny S. Gustafsson, András Birinyi, John Crum, Mark Ellisman, Lennart Brodin, Oleg Shupliakov
Dátum:	2002
ISSN:	0021-9967
Megjegyzések:	The giant reticulospinal synapse in lamprey provides a unique model to study synaptic vesicle traffic. The axon permits microinjections, and the active zones are often separated from each other, which makes it possible to track vesicle cycling at individual release sites. However, the proportion of reticulospinal synapses with individual active zones ("simple synapses") is unknown and a quantitative description of their organization is lacking. Here, we report such data obtained by serial section analysis, intermediate-voltage electron microscopy, and electron tomography. The simple synapse was the most common type (78%). It consisted of one active zone contacting one dendritic process. The remaining synapses were "complex," mostly containing one vesicle cluster and two to three active zones synapsing with distinct dendritic shafts. Occasional axosomatic synapses with multiple active zones forming synapses with the same cell were also observed. The vast majority of active zones in all synapse types contained both chemical and electrotonic synaptic specializations. Quantitative analysis of simple synapses showed that the majority had active zones with a diameter of 0.8-1.8 microm. The number of synaptic vesicles and the height of the vesicle cluster in middle sections of serially cut synapses correlated with the active zone length within, but not above, this size range. Electron tomography of simple synapses revealed small filaments between the clustered synaptic vesicles. A single vesicle could be in contact with up to 12 filaments. Another type of filament, also associated with synaptic vesicles, emerged from dense projections. Up to six filaments could be traced from one dense projection.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal of Comparative Neurology. - 450 : 2 (2002), p. 167-182. -
További szerzők:	Birinyi András (1960-) (anatómus, neurobiológus) Crum, John Ellisman, Mark Brodin, Lennart Shupliakov, Oleg
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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