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Titolo:
DIMENSIONS AND DENSITY OF DENDRITIC SPINES FROM RAT DENTATE GRANULE CELLS BASED ON RECONSTRUCTIONS FROM SERIAL ELECTRON-MICROGRAPHS
Autore:
TROMMALD M; HULLEBERG G;
Indirizzi:
UNIV OSLO,DEPT NEUROPHYSIOL,PB 1104 N-0317 OSLO NORWAY
Titolo Testata:
Journal of comparative neurology
fascicolo: 1, volume: 377, anno: 1997,
pagine: 15 - 28
SICI:
0021-9967(1997)377:1<15:DADODS>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
LONG-TERM POTENTIATION; EXCITATORY POSTSYNAPTIC CURRENTS; PARTITIONED TRANSMISSION ZONES; LESION-INDUCED SYNAPTOGENESIS; CEREBRAL-CORTEX; SYNAPTIC TRANSMISSION; AXOSPINOUS SYNAPSES; PYRAMIDAL CELLS; 3-DIMENSIONAL STRUCTURE; ADULT RAT;
Keywords:
HIPPOCAMPUS; 3-DIMENSIONAL RECONSTRUCTION; SPINE DIMENSIONS; SPINE DENSITY; SPINE CLASSIFICATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
67
Recensione:
Indirizzi per estratti:
Citazione:
M. Trommald e G. Hulleberg, "DIMENSIONS AND DENSITY OF DENDRITIC SPINES FROM RAT DENTATE GRANULE CELLS BASED ON RECONSTRUCTIONS FROM SERIAL ELECTRON-MICROGRAPHS", Journal of comparative neurology, 377(1), 1997, pp. 15-28

Abstract

In the hippocampus, most excitatory synapses are located on dendriticspines. It has been postulated that the geometry of spines and/or thepostsynaptic density (PSD) in fluences synaptic efficiency and may contribute to the expression of plastic processes such as learning or long-term potentiation (LTP). Based on three-dimensional reconstructionsof dentate granule cell dendrites from serial electron micrographs, we have measured head dimensions, neck cross-sectional areas, neck length, and PSD area and form of 115 spines of dentate granule cells in the medial perforant path termination zone. All dimensions showed a large variability, with up to 100-fold differences in values. A calculateddiffusion index for transport of molecules through the reconstructed neck varied over a 100-fold range. The neck and head dimensions were moderately positively correlated, whereas the PSD area was strongly correlated with head volume. Distribution histograms and scatter plots ofvarious spine dimensions did not reveal any systematic clustering, suggesting that there is a continuum of spine geometries rather than distinct classes for granule cell dendritic spines in the middle molecular layer. Transversely (n = 13) and longitudinally (n = 27) sectioned dendrites had mean spine densities of 2.66 and 1.01 spines/mu m, respectively, uncorrected for so-called hidden spines. Bifurcating spines made up 2.1% of the total spine number in transversely and 2.3% in longitudinally sectioned dendrites. The twin spine heads never shared the same presynaptic bouton. Fenestrated or split PSDs shared the same presynaptic element in all but two cases, arguing against PSD division as an intermediate step in synapse formation. (C) 1997 Wiley-Liss, Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/08/20 alle ore 00:39:12