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Titolo:
Total number and distribution of inhibitory and excitatory synapses on hippocampal CA1 pyramidal cells
Autore:
Megias, M; Emri, Z; Freund, TF; Gulyas, AI;
Indirizzi:
Hungarian Acad Sci, Inst Expt Med, H-1450 Budapest, Hungary Hungarian AcadSci Budapest Hungary H-1450 Med, H-1450 Budapest, Hungary
Titolo Testata:
NEUROSCIENCE
fascicolo: 3, volume: 102, anno: 2001,
pagine: 527 - 540
SICI:
0306-4522(2001)102:3<527:TNADOI>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
LONG-TERM POTENTIATION; GAMMA-AMINOBUTYRIC ACID; RAT HIPPOCAMPUS; DENDRITIC SPINES; BEHAVING RAT; IMMUNOREACTIVE INTERNEURONS; DENTATE GYRUS; NEURONS; VARIABILITY; SELECTIVITY;
Keywords:
synaptic convergence; dendrite geometry; serial reconstruction; 3D; electron microscopy; database for modeling;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
36
Recensione:
Indirizzi per estratti:
Indirizzo: Gulyas, AI Hungarian Acad Sci, Inst Expt Med, POB 67, H-1450 Budapest, Hungary Hungarian Acad Sci POB 67 Budapest Hungary H-1450 est, Hungary
Citazione:
M. Megias et al., "Total number and distribution of inhibitory and excitatory synapses on hippocampal CA1 pyramidal cells", NEUROSCIENC, 102(3), 2001, pp. 527-540

Abstract

The integrative properties of neurons depend strongly on the number, proportions and distribution of excitatory and inhibitory synaptic inputs they receive. In this study the three-dimensional geometry of dendritic trees andthe density of symmetrical and asymmetrical synapses on different cellularcompartments of rat hippocampal CA1 area pyramidal cells was measured to calculate the total number and distribution of excitatory and inhibitory inputs on a single cell. A single pyramidal cell has similar to 12,000 mum dendrites and receives around 30,000 excitatory and 1700 inhibitory inputs, of which 40% are concentrated in the perisomatic region and 20% on dendrites in the stratum lacunosum-moleculare. The pre and post-synaptic features suggest that CA 1 pyramidal cell dendrites are heterogeneous. Strata radiatum and oriens dendrites are similar and differ from stratum lacunosum-moleculare dendrites. Proximal apical and basal strata radiatum and oriens dendrites are spine-free or sparsely spiny. Distal strata radiatum and oriens dendrites (forming 68.5% of the pyramidal cells ' dendrite tree) are densely spiny; their excitatory inputs terminate exclusively on dendritic spines, while inhibitory inputs target only dendritic shafts. The proportion of inhibitory inputs on distal spiny strata radiatum and oriens dendrites is low (similar to3%). In contrast, proximal dendritic segments receive mostly (70-100%) inhibitory inputs. Only inhibitory inputs innervate the somata (77-103 per cell) and axon initial segments. Dendrites in the stratum lacunosum-moleculare possess moderate to small amounts of spines. Excitatory synapses: on stratum lacunosum-moleculare dendrites are larger than the synapses in other layers, are frequently perforated (similar to 40%) and can be located on dendritic shafts. Inhibitory inputs, whose percentage is relatively high (similar to 14-17%), also terminate on dendritic spines. Our results indicate that: (i) the highly convergent excitation arriving onto the distal dendrites of pyramidal cells is primarily controlled by proximally located inhibition; (ii) the organization of excitatory and inhibitory inputs in layers receiving Schaffer collateral input (radiatum/oriens) versus perforant path input (lacunosum-moleculare) is significantly different. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/01/20 alle ore 20:43:56