title: Metabolic demands of neural-hemodynamic associated and disassociated areas in brain.
abstract: Interpretation of regional blood oxygenation level-dependent (BOLD) responses in functional magnetic resonance imaging (fMRI) is contingent on whether local field potential (LFP) and multi-unit activity (MUA) is either dissociated or associated. To examine whether neural-hemodynamic associated and dissociated areas have different metabolic demands, we recorded sensory-evoked responses of BOLD signal, blood flow (CBF), and blood volume (CBV), which with calibrated fMRI provided oxidative metabolism (CMRO2) from rat's ventral posterolateral thalamic nucleus (VPL) and somatosensory forelimb cortex (S1FL) and compared these neuroimaging signals to neurophysiological recordings. MUA faithfully recorded evoked latency differences between VPL and S1FLbecause evoked MUA in these regions were similar in magnitude. Since evoked LFP was significantly attenuated in VPL, we extracted the time courses of the weaker thalamic LFP to compare with the stronger cortical LFP using wavelet transform. BOLD and CBV responses were greater in S1FLthan in VPL, similar to LFP regional differences. CBF and CMRO2responses were both comparably larger in S1FLand VPL. Despite different levels of CBF-CMRO2and LFP-MUA couplings in VPL and S1FL, the CMRO2was well matched with MUA in both regions. These results suggest that neural-hemodynamic associated and dissociated areas in VPL and S1FLcan have similar metabolic demands.
authors: Magnetic Resonance Research Center (MRRC), Yale University, New Haven, USA Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, USA Department of Radiology and Biomedical Imaging, Yale University, New Haven, USA basavaraju.ganganna@yale.edu fahmeed.hyder@yale.edu.
authors: Basavaraju G
authors: BG
authors: Sanganahalli
authors: Magnetic Resonance Research Center (MRRC), Yale University, New Haven, USA Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, USA Department of Radiology and Biomedical Imaging, Yale University, New Haven, USA.
authors: Peter
authors: P
authors: Herman
authors: Magnetic Resonance Research Center (MRRC), Yale University, New Haven, USA Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, USA Department of Radiology and Biomedical Imaging, Yale University, New Haven, USA Department of Biomedical Engineering, Yale University, New Haven, USA.
authors: Douglas L
authors: DL
authors: Rothman
authors: Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, USA Department of Neurology, Yale University, New Haven, USA Department of Neurobiology, Yale University, New Haven, USA.
authors: Hal
authors: H
authors: Blumenfeld
authors: Magnetic Resonance Research Center (MRRC), Yale University, New Haven, USA Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, USA Department of Radiology and Biomedical Imaging, Yale University, New Haven, USA Department of Biomedical Engineering, Yale University, New Haven, USA.
authors: Fahmeed
authors: F
authors: Hyder
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D059907:Functional Neuroimaging; D006439:Hemodynamics / Q000502:physiology*; D017078:Laser-Doppler Flowmetry; D008279:Magnetic Resonance Imaging; D008297:Male; D009474:Neurons / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013003:Somatosensory Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D020651:Ventral Thalamic Nuclei / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology
keywords: Glutamate; neuroenergetics; neurometabolic; neurovascular; spike rate