Basavaraju G. Sanganahalli1,2, Peter Herman1,2, Douglas L. Rothman2,3, Hal Blumenfeld2,4, Fahmeed Hyder2,3
1Diagnostic Radiology, Yale University, New Haven, CT, USA; 2Quantitative Neuroscience with Magnetic Resonance in Medicine (QNMR), Yale University, New Haven, CT, USA; 3Diagnostic Radiology & Biomedical Engineering, Yale University, New Haven, CT, USA; 4Neurology, Neurosurgery, Neuroscience, Yale University, New Haven, CT, USA
Because oxidative demands in cortex and subcortex are largely unknown, we evaluated regional energetics with high field calibrated fMRI in rat brain. During somatosensory stimulation we measured BOLD, CBV, and CBF to calculate δCMRO2 in cortex and subcortex and compared these with neural recordings. We find that while neural-BOLD, neural-CBV, and neural-CBF relationships differ significantly between cortex and subcortex, δCMRO2 values are quite similar in these regions. These regional energetic estimates from calibrated fMRI are in agreement with neural recordings. Thus these results suggest that neurometabolic couplings are similar in cortex and subcortex, but neurovascular couplings are quite different.