Intracortical connectivity of layer VI pyramidal neurons in the somatosensory cortex of normal and barrelless mice.

Détails

ID Serval
serval:BIB_463C036D0C7D
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Intracortical connectivity of layer VI pyramidal neurons in the somatosensory cortex of normal and barrelless mice.
Périodique
European Journal of Neuroscience
Auteur(s)
Pichon F., Nikonenko I., Kraftsik R., Welker E.
ISSN
1460-9568 (Electronic)
ISSN-L
0953-816X
Statut éditorial
Publié
Date de publication
2012
Peer-reviewed
Oui
Volume
35
Numéro
6
Pages
855-869
Langue
anglais
Résumé
In mice, barrels in layer IV of the somatosensory cortex correspond to the columnar representations of whisker follicles. In barrelless (BRL) mice, barrels are absent, but functionally, a columnar organization persists. Previously we characterized the aberrant geometry of thalamic projection of BRL mice using axonal reconstructions of individual neurons. Here we proceeded with the analysis of the intracortical projections from layer VI pyramidal neurons, to assess their contribution to the columnar organization. From series of tangential sections we reconstructed the axon collaterals of individual layer VI pyramidal neurons in the C2 barrel column that were labelled with biocytin [controls from normal (NOR) strain, 19 cells; BRL strain, nine cells]. Using six morphological parameters in a cluster analysis, we showed that layer VI neurons in NOR mice are distributed into four clusters distinguished by the radial and tangential extent of their intracortical projections. These clusters correlated with the cortical or subcortical projection of the main axon. In BRL mice, neurons were distributed within the same four clusters, but their projections to the granular and supragranular layers were significantly smaller and their tangential projection was less columnar than in NOR mice. However, in both strains the intracortical projections had a preference for the appropriate barrel column (C2), indicating that layer VI pyramidal cells could participate in the functional columnar organization of the barrel cortex. Correlative light and electron microscopy analyses provided morphometric data on the intracortical synaptic boutons and synapses of layer VI pyramidal neurons and revealed that projections to layer IV preferentially target excitatory dendritic spines and shafts.
Mots-clé
barrel cortex, cortical column, layer VI, morphological analysis, pyramidal neuron
Pubmed
Web of science
Création de la notice
23/05/2012 12:51
Dernière modification de la notice
03/03/2018 16:47
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