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001-es BibID:	BIBFORM029087
Első szerző:	Antal Miklós (orvos, anatómus)
Cím:	Development, neurochemical properties and axonal projections of a population of last-order premotor interneurons in the white matter of the chick lumbosacral spinal cord / Antal M., Puskár Z., Birinyi A., Storm-Mathisen J.
Dátum:	2000
ISSN:	1552-5007
Megjegyzések:	There is general agreement that last-order premotor interneurons-a set of neurons that integrate activities generated by the spinal motor apparatus, sensory information and volleys arising from higher motor centres, and transmit the integrated signals to motoneurons through monosynaptic contacts-play crucial roles in the initiation and maintenance of spinal motor activities. Here, we demonstrate the development, neurochemical properties, and axonal projections of a unique group of last-order premotor interneurons within the ventrolateral aspect of the lateral funiculus of the chick lumbosacral spinal cord. Neurons expressing immunoreactivity for neuron-specific enolase were first detected in the ventrolateral white matter at embryonic day 9 (E9). The numbers of immunoreactive neurons were significantly increased at E10-E12, while most of them were gradually concentrated in small segmentally arranged nuclei (referred to as major nuclei of Hofmann) protruding from the white matter in a necklace like fashion dorsal to the ventral roots. The major nuclei of Hofmann became more prominent at E12-E16, but substantial numbers of cells were still located within the ventrolateral white matter (referred to as minor nucleus of Hofmann). The distribution of immunoreactive neurons achieved by E16 was maintained during later developmental stages and was also characteristic of adult animals. After injection of Phaseolus vulgaris-leucoagglutinin unilaterally into the minor nucleus of Hofmann, labeled fibres were detected in the ventrolateral white matter ipsilateral to the injection site. Ascending and descending fibres were revealed throughout the entire rostro-caudal length of the lumbosacral spinal cord. Axon terminals were predominantly found within the lateral motor column and the ventral regions of lamina VII ipsilateral to the injection site. Several axon varicosities made close appositions with somata and dendrites of motoneurons, which were identified as synaptic contacts in a consecutive electron microscopic study. With the postembedding immunogold method, 21 of 97 labeled terminals investigated were immunoreactive for glycine and 2 of them showed immunoreactivity for gamma-aminobutyric acid (GABA). The axon trajectories of neurons within the minor nucleus of Hofmann suggest that some of these cells might represent a population of last-order premotor interneurons
Tárgyszavak:	Orvostudományok Elméleti orvostudományok magyar nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal Of Experimental Zoology. - 286 : 2 (2000), p. 157-172. -
További szerzők:	Puskár Zita Birinyi András (1960-) (anatómus, neurobiológus) Storm-Mathisen, John
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001-es BibID:	BIBFORM028817
Első szerző:	Antal Miklós (orvos, anatómus)
Cím:	Development of specific populations of interneurons in the ventral horn of the embryonic chick lumbosacral spinal cord / Antal M., Polgár E., Berki Á., Birinyi A., Puskár Z.
Dátum:	1994
Megjegyzések:	The development, morphological and neurochemical properties of specific populations of interneurons were investigated in the ventral horn of the embryonic and mature chick lumbosacral spinal cord by using pre- and post-embedding immunocytochemical as well as anterograde axonal tracing techniques. We have identified and traced the morphological maturation of the following cell groups: (1) Neurons immunoreactive for calbindin-D 28k (CaB), a calcium-binding protein that has been reported to be a marker of certain subsets of excitatory spinal neurons. We have distinguished and traced the maturation of three CaB-immunoreactive cell groups in the ventral horn; (2) Neurons immunoreactive for GABA and glycine, the two putative inhibitory amino acid neurotransmitters in the spinal cord; (3) Neurons within the nucleus marginalis, a cell group located in the ventrolateral aspect of the white matter in close proximity to the lateral motor column. The characteristic features of the development of these neurons are discussed and correlated with previous neuroanatomical and physiological studies concerning motor functions in the developing chick spinal cord.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	European Journal of Morphology. - 32 : 2-4 (1994), p. 201-206. -
További szerzők:	Polgár E. Berki Á. Birinyi András (1960-) (anatómus, neurobiológus) Puskár Zita
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM029090
Első szerző:	Dityatev, A. E.
Cím:	A correlative physiological and morphological analysis of monosynaptically connected propriospinal axon - motoneuron pairs in the lumbar spinal cord of frogs / Dityatev A. E., Birinyi A., Puskár Z., Antal M., Clamann P.
Dátum:	2001
ISSN:	0306-4522
Megjegyzések:	Intracellular stimulation of single propriospinal axons evoked excitatory postsynaptic potentials (EPSPs) in lumbar motoneurons. Mean EPSP amplitudes differed by two orders of magnitude when measured in different connections. After analyzing the distribution of mean amplitudes of 47 single-fiber EPSPs, two populations of responses could be defined: (1) those with mean amplitudes between 0.1 and 1.2 mV (mean+/-S.D.: 0.48+/-0.30 mV, 34 pairs), which is in the range of values typical for single-fiber EPSPs evoked by stimulation of supraspinal fibers and primary muscle afferents, (2) those with mean amplitudes between 1.6 and 8 mV (4.2+/-2.0 mV, 13 pairs). Both populations of responses had similarly short latencies and rise times and responded similarly to paired-pulse stimulation, consistent with monosynaptic transmission. However, the high-efficacy connections had significantly smaller coefficients of variation of EPSPs, as well as increased quantal content and quantal size. Tetanic stimulation gradually depressed the amplitude of large EPSPs by 81-86%, but did not affect small EPSPs. Recovery of large EPSPs was exponential with a time constant of 3-5.6 min. During post-tetanic depression the amplitude ratio between the test and conditioned EPSPs evoked by paired-pulse stimulation was not changed but the coefficient of variation was increased, suggesting that the depression was due to depletion of synaptic vesicles available for release.Intracellular labeling of seven electrophysiologically studied propriospinal axon-motoneuron pairs revealed that the number of axon varicosities establishing close appositions with dendrites of the labeled motoneuron was higher for connections where large-amplitude EPSPs were recorded. These varicosities were more often located on proximal dendrites of motoneurons than those of low-efficacy connections. In addition, the number of boutons in highly effective connections was several times lower than the maximal number of available quanta estimated from physiological data, implying that the large EPSPs may be generated by multivesicular release from presynaptic boutons. We conclude that the efficacy and related mode of use-dependent modulation of propriospinal connections is determined by a number of factors, including the number and position of synaptic contacts and the number of active zones or vesicles available for release.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok magyar nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Neuroscience. - 106 : 2 (2001), p. 405-417. -
További szerzők:	Birinyi András (1960-) (anatómus, neurobiológus) Puskár Zita Antal Miklós (1951-) (orvos, anatómus) Clamann, P.
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001-es BibID:	BIBFORM029492
Első szerző:	Wolf Ervin (fizikus, neurobiológus)
Cím:	Morphometric descriptors and cable modelling of dendritic arborizations based on 3-dimensional reconstructions / Wolf E., Birinyi A., Puskár Z.
Dátum:	1996
ISSN:	0236-5383
Megjegyzések:	The main goal of this paper is twofold. First, to classify some of the quantitative morphological descriptors within a common theoretical framework and to illustrate their use in the neurobiological research. The second aim is to describe how the computer modelling of dendritic impulse propagation could be related to those high-fidelity morphological databases of dendritic arborizations that we had obtained by three-dimensional reconstructions. Most of the illustrative examples cited here were chosen from morphological and computer simulation studies published by our institute in the past few years. The selection of different morphological parameters in reliability tests of our newly developed 3DARBOR three-dimensional neuronal tree reconstruction system was also cited as an example. The advantages of the parallelled morphological and computational approach in the study of dendritic arborizations were discussed. A full flow chart that gives an outline of the methods we followed in setting up a morphologically accurate cable model was also presented.
Tárgyszavak:	Orvostudományok Természettudományok Biológiai tudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban egyetemen (Magyarországon) készült közlemény
Megjelenés:	Acta Biologica Hungarica. - 47 : 1-4 (1996), p. 427-439. -
További szerzők:	Birinyi András (1960-) (anatómus, neurobiológus) Puskár Zita
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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