Research

Overview

The research performed in the Yale MRS group is as diverse as its faculty. The long and rich history of the Yale MRS group with the study of metabolism using heteronuclear (¹³C, ¹⁵N, ³¹P) MRS techniques still remains a prime focus point today. Among the many collaborations, ¹³C MRS is applied to study metabolism in diabetes (Douglas Rothman) and psychiatric disorders (Graeme Mason). Fahmeed Hyder is studying cerebral metabolism in relation to neuronal activity and function with a wide range of techniques, whereas Kevin Behar is studying cerebral metabolism under a variety of conditions, like hypoxia. The research of Robin de Graaf focuses on the further development of MR methods and hardware to enhance the MRS information content and reliability.

Current Projects

Robin deGraaf: My current research covers three areas. Developing methods to achieve magnetic field uniformity throughout the human and animal brain are central to the technological innovation of my research. The problem of magnetic field inhomogeneity is tackled through dynamic shimming and through the use of electrical coil and passive shim element arrays. ¹³C NMR methods have been pioneered at the Yale MRRC and part of my research is to extend those methods to achieve 3D coverage, higher sensitivity (through ¹H detection), and higher specificity (e.g. GABA turnover detection). Finally, the field of ¹⁷O NMR appears promising for fast and sensitive mapping of a variety of metabolic fluxes. Research covers the synthesis of ¹⁷O-labeled compounds, the development of novel ¹⁷O MR methods, and the in vivo detection of ¹⁷O label turnover.

Fahmeed Hyder: Below are some specific topics of ongoing research in my laboratory.

• High spatiotemporal resolution fMRI at ultra-high fields: Sensory columns at extremely high resolution.
• Electrophysiological basis of BOLD signal: Excitatory and inhibitory neural events underlying the BOLD response.
• Rheological basis of BOLD signal: Contributions of blood plasma and erythrocytes on the BOLD response.
• Energetics of neuronal populations by fMRI: Subcortical mechanisms underlying cortical activations for unisensory and multisensory stimuli.
• Translation of smart contrast agents for tumor characterization by MR: Synthesize and translate agents for improved biosensing of pH and temperature by MR.

Graeme Mason: My research integrates quantitative approaches to measure functional brain chemistry and the study of neuropsychiatric disorders. The primary methods used are 1H and 13C magnetic resonance spectroscopy and mathematical assessment of metabolism. Current areas of research are depression, manic-depressive disorder, alcoholism, panic disorder, premenstrual syndrome, and post-partum depression. My primary areas of interest are the effects of alcohol and nicotine dependence on the brain, and to that end, my research program evaluate acute and chronic effects of alcohol and nicotine on the brain, from perspectives of neurotransmission, metabolism, adaptation, and vulnerability to dependence.