Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-9-25
pubmed:abstractText
Synapses are the key elements for signal transduction and plasticity in the brain. For a better understanding of the functional signal cascades underlying synaptic transmission, a quantitative morphological analysis of the pre- and postsynaptic structures that represent morphological correlates for synaptic transmission is important. In particular, realistic values of the number, distribution, and geometry of synaptic contacts and the organization of the pool of synaptic vesicles provide important constraints for realistic models and numerical simulations of those parameters of synaptic transmission that, at present, are still not accessible to experiment. Although all synapses are composed of almost the same structural elements, the composition of these elements within a given synapse and the microcircuit in which they are embedded are the deciding factors determining its function. One possible way to analyze these structures is by computer-assisted three-dimensional reconstructions of synapses and their subsequent quantitative analysis based on ultrathin serial sections. The present review summarizes and discusses the morphology of five central excitatory synapses that are quantitatively well described: (1) a giant synapse, the so-called Calyx of Held, in the medial nucleus of the trapezoid body in the auditory brain stem, (2) the mossy fiber terminal establishing synapses with multiple cerebellar granule cell dendrites, (3) the mossy fiber bouton in the hippocampus predominantly terminating on proximal dendrites of CA3 pyramidal neurons, (4) the climbing fiber-Purkinje cell synapse in the cerebellum, and (5) cortical input synapses on the basal dendrites of layer 5 pyramidal cells. The detailed morphological description of these synaptic structures may help to define the morphological correlates of the functional parameters of synaptic transmission, such as the readily releasable pool of synaptic vesicles, of release, and of the variability of quantal size and might therefore explain the existing differences in the function between individual synapses embedded in different microcircuits.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0302-766X
pubmed:author
pubmed:issnType
Print
pubmed:volume
326
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
221-37
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
The morphology of excitatory central synapses: from structure to function.
pubmed:affiliation
Institute of Neuroscience and Biophysics, Department of Medicine, Research Center Jülich, D-52425, Jülich, Germany.
pubmed:publicationType
Journal Article, Review