Nuclear magnetic resonance as a tool to study brain metabolism

Nuclei which are most appropriate for nuclear magnetic resonance (NMR) spectroscopy in biological systems include, in decreasing sensitivity, 1H, 19F, 23Na, 31P, 13C and 15N. Proton NMR has achieved remarkable prominence in imaging of the brain, and though clinical 1H spectroscopy is still in its infancy, current developments indicate that it will provide interesting information on brain metabolism. The naturally abundant form of phosphorus (31P) has proved particularly useful in studies on energy metabolism in metabolically perturbed states in the brain in vivo and in vitro. Dynamic studies on turnover rates of ATP and creatine phosphate can be performed using saturation transfer techniques. The use of 13C to follow intermediary metabolism shows great potential, even though it is a relatively insensitive nucleus and has only 1% natural abundance. 19F is a highly sensitive and naturally abundant nucleus. When covalently attached to various chelators, it provides a most sensitive method for accurate measurement of many cations of biological importance, by virtue of the chemical shift of the 19F on binding of the cation to the chelator.