Robert G. Shulman

My research is focused on non-invasive nuclear magnetic resonance studies in vivo of humans and animals. In particular, I have been studying the regional activation of the brain during sensory stimulation such as seeing and hearing and have developed methods for measuring the increased consumption of glucose and oxygen which provide the energy required. An extension of this approach measures the regional activation of the human brain during cognitive tasks. In vivo NMR measurements have been used to follow the rates of glucose odixation and glutamate neurotransmitter activity to be determined from the rates of glucose oxidation. Since functional imaging responds to glucose oxidation it provides, in this way, a direct measure of neuronal activation. I have also used in vivo NMR to follow glucose metabolism in the human muscle. The storage of glucose as glycogen has been measured under a variety of conditions and has provided insights into the cause of diabetes, the storage of glycogen for exercise and the basic understanding of flux control in the glucose storage pathway. This understanding has led to a new general role for the phosphorylation of enzymes showing how phosphorylation serves to maintain constant levels of metabolites during changes in flux. This provides a comprehensive, widely applicable understanding of the control of biochemical fluxes.