Neuronal-glial glucose oxidation and glutamatergic-GABAergic function revealed by 13C MRS studies
Patel A, Rothman D, Behar K, Hyder F, Shulman R, Gjedde A
Magnetic Resonance Research Center, Yale University
Recent 13C MRS results, of total cycling (Vcyc(tot)), neuronal and glial glucose oxidation (CMRglc(ox),N), are used to revise a model of neurotransmitter cycling and energy metabolism which excluded energetics of glia and GABA neurons. The revised model shows that neurons produce ~3.7 more ATP oxidatively than glia, and glutamatergic neurons generate ~4.6 more ATP than GABAergic neurons. Although neurons produce ~79% of total oxidative ATP, neuronal glucose uptake is only ~30% of the total glucose oxidized. Glial lactate still makes the major contribution to neuronal oxidation. The relationship observed between ΔCMRglc(ox),N and ΔVcyc(tot) is maintained by glial glycolysis as before.