Mécanismes cellulaires du métabolisme énergétique cérébral: implications pour l'imagerie fonctionnelle

Détails

ID Serval
serval:BIB_6DF2B85B480A
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Mécanismes cellulaires du métabolisme énergétique cérébral: implications pour l'imagerie fonctionnelle
Périodique
M/S Médecine Sciences
Auteur(s)
Magistretti P.J., Pellerin L.
ISSN
0767-0974
Statut éditorial
Publié
Date de publication
1999
Volume
15
Numéro
4
Pages
451-456
Langue
français
Notes
Cellular mechanisms of brain energy metabolism: implications for functional brain imaging
Résumé
Signals detected with functional brain imaging techniques are based on the coupling of neuronal activity with energy metabolism. Techniques such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) allow the visualization of brain areas that are activated by a variety of sensory, motor or cognitive tasks. Despite the technological sophistication of these brain imaging techniques, the precise mechanisms and cell types involved in coupling and in generating metabolic signals are still debated. Recent experimental data on the cellular and molecular mechanisms that underlie the fluorodeoxyglucose (FDG) - based PET imaging point to a critical role of a particular brain cell type, the astrocytes, in coupling neuronal activity to glucose utilization. Indeed, astrocytes possess receptors and re-uptake sites for a variety of neurotransmitters, including glutamate, the predominant excitatory neurotransmitter in the brain, In addition, astrocytic end-feet, which surround capillaries, are enriched in the specific glucose transporter GLUT-1. These features allow astrocytes to "sense" synaptic activity and to couple it with energy metabolism. In vivo and in vitro data support the following functional model: in response to glutamate released by active neurons, glucose is predominantly taken up by astrocytic end-feet; glucose is then metabolized to lactate which provides a preferred energy substrate for neurons. These data support the notion that astrocytes markedly contribute to the FDG-PET signal.
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Création de la notice
24/01/2008 13:16
Dernière modification de la notice
20/08/2019 14:27
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