Glutamate and GABA are the major excitatory and inhibitory neurotransmitters in the central nervous system and together account for the majority of all of its neurons. Their synaptic actions are maintained through the operation of complex metabolic cycles between neurons and neighboring astroglia. Work in our laboratory is centered on deciphering the mechanism(s) linking glutamate and GABA neurotransmitter cycling to brain activity, and the role of glucose and alternate substrates (e.g., monocarboxylic acids) in this process. Our studies employ nuclear magnetic resonance (NMR) spectroscopy with stable isotope labeling (13C, 15N) and kinetic modeling to study metabolic pathway fluxes in neurons and glia of the intact brain in vivo. This work is being applied to study the role of altered glucose and neurotransmitter metabolism in rodent models of diabetes, depression, and epilepsy. Our laboratory uses Magnetic Resonance Spectroscopy and Imaging (MRS/I) in conjunction with stable 13C-labeled substrates, which can be introduced into the bloodstream in rodents to ‘visualize’ the pathways of brain glucose and energy metabolism and the synthesis of the neurotransmitter amino acids glutamate (excitatory) and GABA (inhibitory).
Specialized Terms: NMR; 1H NMR; 13C NMR; In vivo brain metabolism; Glutamate; Gamma-aminobutyrate; Glutamine; Neuron-glial trafficking
Central Nervous System; Glutamates; Glutamine; Psychiatry; Nuclear Magnetic Resonance, Biomolecular