TY - JOUR
T1 - Uniform distributions of glucose oxidation and oxygen extraction in gray matter of normal human brain
T2 - No evidence of regional differences of aerobic glycolysis
AU - Hyder, Fahmeed
AU - Herman, Peter
AU - Bailey, Christopher J.
AU - Møller, Arne
AU - Globinsky, Ronen
AU - Fulbright, Robert K.
AU - Rothman, Douglas L.
AU - Gjedde, Albert
N1 - Publisher Copyright:
© 2016 The Author(s).
PY - 2015
Y1 - 2015
N2 - Regionally variable rates of aerobic glycolysis in brain networks identified by resting-state functional magnetic resonance imaging (R-fMRI) imply regionally variable adenosine triphosphate (ATP) regeneration. When regional glucose utilization is not matched to oxygen delivery, affected regions have correspondingly variable rates of ATP and lactate production. We tested the extent to which aerobic glycolysis and oxidative phosphorylation power R-fMRI networks by measuring quantitative differences between the oxygen to glucose index (OGI) and the oxygen extraction fraction (OEF) as measured by positron emission tomography (PET) in normal human brain (resting awake, eyes closed). Regionally uniform and correlated OEF and OGI estimates prevailed, with network values that matched the gray matter means, regardless of size, location, and origin. The spatial agreement between oxygen delivery (OEFâ ‰-0.4) and glucose oxidation (OGI â ‰- 5.3) suggests that no specific regions have preferentially high aerobic glycolysis and low oxidative phosphorylation rates, with globally optimal maximum ATP turnover rates (V ATP â ‰- 9.4 μmol/g/min), in good agreement with 31 P and 13 C magnetic resonance spectroscopy measurements. These results imply that the intrinsic network activity in healthy human brain powers the entire gray matter with ubiquitously high rates of glucose oxidation. Reports of departures from normal brain-wide homogeny of oxygen extraction fraction and oxygen to glucose index may be due to normalization artefacts from relative PET measurements.
AB - Regionally variable rates of aerobic glycolysis in brain networks identified by resting-state functional magnetic resonance imaging (R-fMRI) imply regionally variable adenosine triphosphate (ATP) regeneration. When regional glucose utilization is not matched to oxygen delivery, affected regions have correspondingly variable rates of ATP and lactate production. We tested the extent to which aerobic glycolysis and oxidative phosphorylation power R-fMRI networks by measuring quantitative differences between the oxygen to glucose index (OGI) and the oxygen extraction fraction (OEF) as measured by positron emission tomography (PET) in normal human brain (resting awake, eyes closed). Regionally uniform and correlated OEF and OGI estimates prevailed, with network values that matched the gray matter means, regardless of size, location, and origin. The spatial agreement between oxygen delivery (OEFâ ‰-0.4) and glucose oxidation (OGI â ‰- 5.3) suggests that no specific regions have preferentially high aerobic glycolysis and low oxidative phosphorylation rates, with globally optimal maximum ATP turnover rates (V ATP â ‰- 9.4 μmol/g/min), in good agreement with 31 P and 13 C magnetic resonance spectroscopy measurements. These results imply that the intrinsic network activity in healthy human brain powers the entire gray matter with ubiquitously high rates of glucose oxidation. Reports of departures from normal brain-wide homogeny of oxygen extraction fraction and oxygen to glucose index may be due to normalization artefacts from relative PET measurements.
KW - Default mode network
KW - PET
KW - energy metabolism
KW - fMRI
KW - glutamate
KW - neurophysiology
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U2 - 10.1177/0271678X15625349
DO - 10.1177/0271678X15625349
M3 - Article
C2 - 26755443
AN - SCOPUS:84964938448
SN - 0271-678X
VL - 36
SP - 903
EP - 916
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
IS - 5
ER -