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001-es BibID:	BIBFORM029496
Első szerző:	Székely György (neurobiológus)
Cím:	Spatial distribution of pre- and postsynaptic sites of primary afferent cutaneous terminals in the frog spinal cord / Székely G., Nagy I., Wolf E., Nagy P.
Dátum:	1989
ISSN:	0306-4522
Megjegyzések:	Axon terminals which could be interpreted as dorsal root boutons, were photographed from a series of 98 ultrathin sections with a Jeol 100B electron microscope. A total of 13 boutons were recovered for computer reconstruction. Two of them were terminal boutons, eight en passant boutons and three boutons were only partially recovered. All boutons contained multiple synaptic sites (maximum 33 and minimum seven) at which axodendritic and axoaxonic synapses were established. Axodendritic synapses were of the asymmetric type and they were directed toward adjacent dendrites. In axoaxonic synapses, which were of the symmetric type, the boutons were invariably on the postsynaptic side. Among the presynaptic profiles axons with spherical and pleomorphic vesicles and dendrites with flattened vesicles could be discerned. On average, each 2.67-mikrom2 bouton surface area contained one presynaptic site at which an axodendritic synapse was established, and each 7-mikrom2 surface area contained one postsynaptic site for an axoaxonic (or dendroaxonic) contact. A tendency of grouping of synaptic sites was observed. Distance measurements between the closest neighbours of all synaptic sites were made in four combinations in boutons with the original and with a random distribution of synaptic sites. The arithmetic mean of distances measured between the presynaptic and the closest postsynaptic sites was almost twice as big as that measured in the reverse direction. The difference between these values became greatly reduced in the case of random distribution. The arithmetic mean of distances between the closest neighbours of presynaptic sites was about the same as that between the closest neighbours of postsynaptic sites. This latter value was considerably increased with randomly distributed synaptic sites. The results suggest a non-random distribution of synaptic sites on the surface of boutons. The analysis of cluster formation of synaptic sites performed with a numerical taxonomy technique revealed that the majority of the 153 synaptic sites were comprised in 27 clusters containing both pre- and postsynaptic sites within the 1-mikrom similarity level. All postsynaptic sites were within 1-mikrom of one or more presynaptic sites.
Tárgyszavak:	Orvostudományok Természettudományok Biológiai tudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban egyetemen (Magyarországon) készült közlemény
Megjelenés:	Neuroscience. - 29 : 1 (1989), p. 175-188. -
További szerzők:	Nagy I. (orvos) Wolf Ervin (1961-) (fizikus, neurobiológus) Nagy Péter
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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