Compartmentalised energy metabolism supporting glutamatergic neurotransmission in response to increased activity in the rat cerebral cortex: A 13C MRS study in vivo at 14.1 T.

Details

Serval ID
serval:BIB_81B052C24F59
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Compartmentalised energy metabolism supporting glutamatergic neurotransmission in response to increased activity in the rat cerebral cortex: A 13C MRS study in vivo at 14.1 T.
Journal
Journal of cerebral blood flow and metabolism
Author(s)
Sonnay S., Duarte J.M., Just N., Gruetter R.
ISSN
1559-7016 (Electronic)
ISSN-L
0271-678X
Publication state
Published
Issued date
05/2016
Peer-reviewed
Oui
Volume
36
Number
5
Pages
928-940
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
Many tissues exhibit metabolic compartmentation. In the brain, while there is no doubt on the importance of functional compartmentation between neurons and glial cells, there is still debate on the specific regulation of pathways of energy metabolism at different activity levels. Using (13)C magnetic resonance spectroscopy (MRS) in vivo, we determined fluxes of energy metabolism in the rat cortex under α-chloralose anaesthesia at rest and during electrical stimulation of the paws. Compared to resting metabolism, the stimulated rat cortex exhibited increased glutamate-glutamine cycle (+67 nmol/g/min, +95%, P < 0.001) and tricarboxylic (TCA) cycle rate in both neurons (+62 nmol/g/min, +12%, P < 0.001) and astrocytes (+68 nmol/g/min, +22%, P = 0.072). A minor, non-significant modification of the flux through pyruvate carboxylase was observed during stimulation (+5 nmol/g/min, +8%). Altogether, this increase in metabolism amounted to a 15% (67 nmol/g/min, P < 0.001) increase in CMRglc(ox), i.e. the oxidative fraction of the cerebral metabolic rate of glucose. In conclusion, stimulation of the glutamate-glutamine cycle under α-chloralose anaesthesia is associated to similar enhancement of neuronal and glial oxidative metabolism.

Keywords
Animals, Astrocytes/metabolism, Carbon Isotopes, Cell Compartmentation, Cerebral Cortex/metabolism, Cerebral Cortex/physiology, Electric Stimulation, Energy Metabolism/physiology, Glutamic Acid/metabolism, Glutamic Acid/physiology, Magnetic Resonance Imaging, Neuroglia/metabolism, Neurons/metabolism, Rats, Synaptic Transmission, Functional MRI (fMRI), energy metabolism, glucose, magnetic resonance, neuronal–glial interaction
Pubmed
Web of science
Open Access
Yes
Create date
05/09/2017 11:52
Last modification date
20/08/2019 14:41
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