¹³C NMR spectroscopy in combination with the infusion of ¹³C‐labeled precursors is currently the only technique that is capable of quantitatively studying energy metabolism, neurotransmission and other metabolic pathways non‐invasively in vivo. ¹H‐[¹³C]‐NMR spectroscopy is a high‐sensitivity alternative to direct ¹³C NMR spectroscopy. The development of improved NMR methods for water suppression, spatial localization, broadband decoupling, shimming and signal quantification, together with the availability of high magnetic field strengths, has made ¹H‐[¹³C]‐NMR spectroscopy the method of choice for the detection of metabolism at a high spatial and/or temporal resolution. ¹H‐[¹³C]‐NMR spectroscopy can now be used to discriminate glutamatergic (excitatory) and GABAergic (inhibitory) neuronal activity. The improved sensitivity allows the detection of metabolism in different tissues (e.g. gray and white matter) and potentially even in smaller structures, like cortical layers. Finally, ¹H‐[¹³C]‐NMR spectroscopy allows the detection of energy metabolism and neurotransmission during functional activation, thereby further strengthening our understanding of the neurochemical basis of brain function. Copyright © 2003 John Wiley & Sons, Ltd.