Energy on demand
Magistretti, P.J.; Pellerin, L.; Rothman, D.L.; Shulman, R.G.
Science 283(5401): 496-497
1999
ISSN/ISBN: 0036-8075 PMID: 9988650 Document Number: 505925
Positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have enabled scientists to visualize which brain areas are activated by particular tasks. Until recently, however, it has been unclear precisely what neuronal activity PET and fMRI experiments measure because both techniques detect signals that reflect brain energy consumption rather than directly measuring brain activity. The writers discuss recent evidence that the neurotransmitter glutamate and a type of glial cell called astrocytes are key elements in the stoichiometric coupling of energy-related neuronal activities and energy metabolism.