Similar perisynaptic glial localization for the Na+,K+-ATPase alpha 2 subunit and the glutamate transporters GLAST and GLT-1 in the rat somatosensory cortex

Détails

Ressource 1Télécharger: serval:BIB_4E0DE0417D68.P001 (1617.29 [Ko])
Etat: Public
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ID Serval
serval:BIB_4E0DE0417D68
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Similar perisynaptic glial localization for the Na+,K+-ATPase alpha 2 subunit and the glutamate transporters GLAST and GLT-1 in the rat somatosensory cortex
Périodique
Cerebral Cortex
Auteur(s)
Cholet  N., Pellerin  L., Magistretti  P. J., Hamel  E.
ISSN
1047-3211 (Print)
Statut éditorial
Publié
Date de publication
05/2002
Volume
12
Numéro
5
Pages
515-25
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: May
Résumé
Several isoenzymes of the Na(+),K(+)-ATPase are expressed in brain but their specific roles are poorly understood. Recently, it was suggested that an isoenzyme of the Na(+),K(+)-ATPase containing the alpha(2) subunit, together with the glutamate transporters GLAST and GLT-1, participate in a coupling mechanism between neuronal activity and energy metabolism taking place in astrocytes. To substantiate this hypothesis, we compared the distribution of alpha(2), GLAST and/or GLT-1 in the rat cerebral cortex using double immunofluorescence and confocal microscopy, and immunocytochemistry at the electron microscopic level. We also investigated the relationship between alpha(2), GLAST or GLT-1 and asymmetrical synaptic junctions (largely glutamatergic) and GABAergic nerve terminals. Results show that the alpha(2) subunit has an exclusive astroglial localization, and that it is almost completely co-distributed with GLAST and GLT-1 when evaluated by confocal microscopy. This similar distribution was confirmed at the ultrastructural level, which further showed that the vast majority of the alpha(2) staining (73% of all labelled elements), like that of GLAST and GLT-1, was located in glial leaflets surrounding dendritic spines and the dendritic and/or axonal elements of asymmetrical (glutamatergic) axo-dendritic synapses. Synapses ensheathed by alpha(2), GLAST or GLT-1 virtually never included (<or=2%) GABAergic nerve terminals or synaptic junctions. However, a subset of GABAergic nerve terminals (10-14%) were directly apposed to asymmetrical axo-dendritic junctions surrounded by alpha(2), GLAST or GLT-1. Altogether these results demonstrate that alpha(2), GLAST and GLT-1 have comparable perisynaptic distribution within cortical astrocytes most likely associated with glutamatergic synapses.
Mots-clé
Amino Acid Transport System X-AG/*analysis/ultrastructure Animals Excitatory Amino Acid Transporter 2/*analysis/ultrastructure Male Na(+)-K(+)-Exchanging ATPase/*analysis/ultrastructure Neuroglia/*chemistry/ultrastructure Rats Rats, Sprague-Dawley Somatosensory Cortex/*chemistry/ultrastructure Synapses/*chemistry/ultrastructure
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 14:17
Dernière modification de la notice
25/09/2019 7:09
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