Összesen 3 találat.


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.
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
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat


001-es BibID:BIBFORM037166
Első szerző:Stelescu András
Cím:Somato-dendritic morphology and dendritic signal transfer properties differentiate between fore- and hindlimb innervating motoneurons in the frog Rana esculenta / Stelescu András, Sümegi János, Wéber Ildikó, Birinyi András, Wolf Ervin
Megjegyzések:BACKGROUND: The location specific motor pattern generation properties of the spinal cord along its rostrocaudal axis have been demonstrated. However, it is still unclear that these differences are due to the different spinal interneuronal networks underlying locomotions or there are also segmental differences in motoneurons innervating different limbs. Frogs use their fore- and hindlimbs differently during jumping and swimming. Therefore we hypothesized that limb innervating motoneurons, located in the cervical and lumbar spinal cord, are different in their morphology and dendritic signal transfer properties. The test of this hypothesis what we report here.RESULTS: Discriminant analysis classified segmental origin of the intracellularly labeled and threedimensionally reconstructed motoneurons 100% correctly based on twelve morphological variables. Somata of lumbar motoneurons were rounder; the dendrites had bigger total length, more branches with higher branching orders and different spatial distributions of branch points. The ventro-medial extent of cervical dendrites was bigger than in lumbar motoneurons. Computational models of the motoneurons showed that dendritic signal transfer properties were also different in the two groups of motoneurons. Whether log attenuations were higher or lower in cervical than in lumbar motoneurons depended on the proximity of dendritic input to the soma. To investigate dendritic voltage and current transfer properties imposed by dendritic architecture rather than by neuronal size we used standardized distributions of transfer variables. We introduced a novel combination of cluster analysis and homogeneity indexes to quantify segmental segregation tendencies of motoneurons based on their dendritic transfer properties. A segregation tendency of cervical and lumbar motoneurons was detected by the rates of steady-state and transient voltageamplitude transfers from dendrites to soma at all levels of synaptic background activities, modeled by varying the specific dendritic membrane resistance. On the other hand no segregation was observed by the steady-state current transfer except under high background activity.CONCLUSIONS: We found size-dependent and size-independent differences in morphology and electrical structure of the limb moving motoneurons based on their spinal segmental location in frogs. Location specificity of locomotor networks is therefore partly due to segmental differences in motoneurons driving fore-, and hindlimbs.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Bmc Neuroscience [electronic resource]. - 13 : 1 (2012), p. 68. -
További szerzők:Sümegi János Wéber Ildikó (1972-) (biológus, neurobiológus) Birinyi András (1960-) (anatómus, neurobiológus) Wolf Ervin (1961-) (fizikus, neurobiológus)
Pályázati támogatás:K67747
Internet cím:DOI
Intézményi repozitóriumban (DEA) tárolt változat


001-es BibID:BIBFORM001430
Első szerző:Wéber Ildikó (biológus, neurobiológus)
Cím:Neurotransmitter systems of commissural interneurons int he lumbar spinal cord of neonatal rats / Wéber I., Veress G., Szűcs P., Antal M., Birinyi A.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Brain Research. - 1178 (2007), p. 65-72. -
További szerzők:Veress Gábor (1971-) (neurobiológus) Szűcs Péter (1974-) (kutatóorvos) Antal Miklós (1951-) (orvos, anatómus) Birinyi András (1960-) (anatómus, neurobiológus)
Pályázati támogatás:046121
Internet cím:elektronikus változat
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