Fiche publication
Date publication
février 2015
Journal
Nature neuroscience
Auteurs
Membres identifiés du Cancéropôle Est :
Dr PFRIEGER Frank
,
Dr COLLOT Mayeul
Tous les auteurs :
Otsu Y, Couchman K, Lyons DG, Collot M, Agarwal A, Mallet JM, Pfrieger FW, Bergles DE, Charpak S
Lien Pubmed
Résumé
Enhanced neuronal activity in the brain triggers a local increase in blood flow, termed functional hyperemia, via several mechanisms, including calcium (Ca(2+)) signaling in astrocytes. However, recent in vivo studies have questioned the role of astrocytes in functional hyperemia because of the slow and sparse dynamics of their somatic Ca(2+) signals and the absence of glutamate metabotropic receptor 5 in adults. Here, we reexamined their role in neurovascular coupling by selectively expressing a genetically encoded Ca(2+) sensor in astrocytes of the olfactory bulb. We show that in anesthetized mice, the physiological activation of olfactory sensory neuron (OSN) terminals reliably triggers Ca(2+) increases in astrocyte processes but not in somata. These Ca(2+) increases systematically precede the onset of functional hyperemia by 1-2 s, reestablishing astrocytes as potential regulators of neurovascular coupling.
Mots clés
Animals, Astrocytes, cytology, Calcium Signaling, physiology, Cerebrovascular Circulation, physiology, Mice, Mice, Transgenic, Olfactory Bulb, cytology, Olfactory Receptor Neurons, metabolism, Receptor, Metabotropic Glutamate 5, metabolism, Synapses, metabolism
Référence
Nat Neurosci. 2015 02;18(2):210-8
