%0 Journal Article
%A Dufour, A.
%A Rollenhagen, A.
%A Sätzler, K.
%A Lübke, Joachim
%T Development of Synaptic Boutons in Layer 4 of the Barrel Field of the Rat Somatosensory Cortex: A Quantitative Analysis
%J Cerebral cortex
%V 26
%N 2
%@ 1460-2199
%C Oxford
%I Oxford Univ. Press
%M FZJ-2015-07899
%P 838-854
%D 2016
%X Understanding the structural and functional mechanisms underlying the development of individual brain microcircuits is critical for elucidating their computational properties. As synapses are the key structures defining a given microcircuit, it is imperative to investigate their development and precise structural features. Here, synapses in cortical layer 4 were analyzed throughout the first postnatal month using high-end electron microscopy to generate realistic quantitative 3D models. Besides their overall geometry, the size of active zones and the pools of synaptic vesicles were analyzed. At postnatal day 2 only a few shaft synapses were found, but spine synapses steadily increased with ongoing corticogenesis. From postnatal day 2 to 30 synaptic boutons significantly decreased in size whereas that of active zones remained nearly unchanged despite a reshaping. During the first 2 weeks of postnatal development, a rearrangement of synaptic vesicles from a loose distribution toward a densely packed organization close to the presynaptic density was observed, accompanied by the formation of, first a putative readily releasable pool and later a recycling and reserve pool. The quantitative 3D reconstructions of synapses will enable the comparison of structural and functional aspects of signal transduction thus leading to a better understanding of networks in the developing neocortex.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000371522500031
%$ pmid:26574502
%R 10.1093/cercor/bhv270
%U https://juser.fz-juelich.de/record/280153