TY - JOUR
T1 - Oxygen consumption and blood flow coupling in human motor cortex during intense finger tapping
T2 - Implication for a role of lactate
AU - Vafaee, Manouchehr S.
AU - Vang, Kim
AU - Bergersen, Linda H.
AU - Gjedde, Albert
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2012/10
Y1 - 2012/10
N2 - Rates of cerebral blood flow (CBF) and glucose consumption (CMR glc) rise in cerebral cortex during continuous stimulation, while the oxygen-glucose index (OGI) declines as an index of mismatched coupling of oxygen consumption (cerebral metabolic rate of oxygen-CMRO 2) to CBF and CMR glc. To test whether the mismatch reflects a specific role of aerobic glycolysis during functional brain activation, we determined CBF and CMRO 2 with positron emission tomography (PET) when 12 healthy volunteers executed finger-to-thumb apposition of the right hand. Movements began 1, 10, or 20 minutes before administration of the radiotracers. In primary and supplementary motor cortices and cerebellum, CBF had increased at 1 minute of exercise and remained elevated for the duration of the 20-minute session. In contrast, the CMRO 2 numerically had increased insignificantly in left M1 and supplementary motor area at 1 minute, but had declined significantly at 10 minutes, returning to baseline at 20 minutes. As measures of CMR glc are impossible during short-term activations, we used measurements of CBF as indices of CMR glc. The decline of CMRO 2 at 10 minutes paralleled a calculated decrease of OGI at this time. The implied generation of lactate in the tissue suggested an important hypothetical role of the metabolite as regulator of CBF during activation.
AB - Rates of cerebral blood flow (CBF) and glucose consumption (CMR glc) rise in cerebral cortex during continuous stimulation, while the oxygen-glucose index (OGI) declines as an index of mismatched coupling of oxygen consumption (cerebral metabolic rate of oxygen-CMRO 2) to CBF and CMR glc. To test whether the mismatch reflects a specific role of aerobic glycolysis during functional brain activation, we determined CBF and CMRO 2 with positron emission tomography (PET) when 12 healthy volunteers executed finger-to-thumb apposition of the right hand. Movements began 1, 10, or 20 minutes before administration of the radiotracers. In primary and supplementary motor cortices and cerebellum, CBF had increased at 1 minute of exercise and remained elevated for the duration of the 20-minute session. In contrast, the CMRO 2 numerically had increased insignificantly in left M1 and supplementary motor area at 1 minute, but had declined significantly at 10 minutes, returning to baseline at 20 minutes. As measures of CMR glc are impossible during short-term activations, we used measurements of CBF as indices of CMR glc. The decline of CMRO 2 at 10 minutes paralleled a calculated decrease of OGI at this time. The implied generation of lactate in the tissue suggested an important hypothetical role of the metabolite as regulator of CBF during activation.
KW - energy metabolism
KW - lactate
KW - neurovascular coupling
KW - positron emission tomography
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U2 - 10.1038/jcbfm.2012.89
DO - 10.1038/jcbfm.2012.89
M3 - Article
C2 - 22781333
AN - SCOPUS:84867084530
VL - 32
SP - 1859
EP - 1868
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
SN - 0271-678X
IS - 10
ER -