Ex-Vivo C NMR Spectroscopy of Rodent Brain: TNF Restricts Neuronal Utilization of Astrocyte-Derived Metabolites.

Tumor necrosis factor (TNF) has well-established roles in neuroinflammatory disorders, but the effect of TNF on the biochemistry of brain cells remains poorly understood. Here, we microinjected TNF into the brain to study its impact on glial and neuronal metabolism (glycolysis, pentose phosphate pathway, citric acid cycle, pyruvate dehydrogenase, and pyruvate carboxylase pathways) using C NMR spectroscopy on brain extracts following intravenous [1,2-C]-glucose (to probe glia and neuron metabolism), [2-C]-acetate (probing astrocyte-specific metabolites), or [3-C]-lactate. An increase in [4,5-C]-glutamine and [2,3-C]-lactate coupled with a decrease in [4,5-C]-glutamate was observed in the [1,2-C]-glucose-infused animals treated with TNF.