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

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 13C 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