Abstract #0457

Chen W, Zhang N, Ugurbil K, Zhang X, Zhang Y, Zhu X

Whether and how much CMRO2 increases during brain activation and how it influences BOLD-based fMRI have been debated for a long time. A major difficulty for resolving this controversy is the lack of reliable techniques for directly imaging CMRO2. Recent developments in the high-field 17O NMR methodology provide a promising tool for noninvasively imaging CMRO2 in animals. We have applied this methodology for obtaining 3D CMRO2 imaging in the cat visual cortex at both resting state and visual stimulation with short inhalation of 17O2 gas. The results indicate (i) a substantial CMRO2 increase in the activated regions and (ii) an essential role of oxidative metabolism in brain function.