TY - JOUR
T1 - Coupling between changes in human brain temperature and oxidative metabolism during prolonged visual stimulation
AU - Yablonskiy, Dmitriy A.
AU - Ackerman, Joseph J.H.
AU - Raichle, Marcus E.
PY - 2000/6/20
Y1 - 2000/6/20
N2 - A fundamental discovery of modern human brain imaging with positron- emission tomography that the blood flow to activated regions of the normal human brain increases substantially more than the oxygen consumption has led to a broad discussion in the literature concerning possible mechanisms responsible for this phenomenon. Presently no consensus exists. It is well known that oxygen delivery is not the only function of systemic circulation. Additional roles include delivery of nutrients and other required substances to the tissue, waste removal, and temperature regulation. Among these other functions, the role of regional cerebral blood flow in local brain temperature regulation has received scant attention. Here we present a theoretical analysis supported by empirical data obtained with functional magnetic resonance suggesting that increase in regional cerebral blood flow during functional stimulation can cause local changes in the brain temperature and subsequent local changes in the oxygen metabolism. On average, temperature decreases by 0.2°C, but individual variations up to ±1°C were also observed. Major factors contributing to temperature regulation during functional stimulation are changes in the oxygen consumption, changes in the temperature of incoming arterial blood, and extensive heat exchange between activated and surrounding brain tissue.
AB - A fundamental discovery of modern human brain imaging with positron- emission tomography that the blood flow to activated regions of the normal human brain increases substantially more than the oxygen consumption has led to a broad discussion in the literature concerning possible mechanisms responsible for this phenomenon. Presently no consensus exists. It is well known that oxygen delivery is not the only function of systemic circulation. Additional roles include delivery of nutrients and other required substances to the tissue, waste removal, and temperature regulation. Among these other functions, the role of regional cerebral blood flow in local brain temperature regulation has received scant attention. Here we present a theoretical analysis supported by empirical data obtained with functional magnetic resonance suggesting that increase in regional cerebral blood flow during functional stimulation can cause local changes in the brain temperature and subsequent local changes in the oxygen metabolism. On average, temperature decreases by 0.2°C, but individual variations up to ±1°C were also observed. Major factors contributing to temperature regulation during functional stimulation are changes in the oxygen consumption, changes in the temperature of incoming arterial blood, and extensive heat exchange between activated and surrounding brain tissue.
UR - http://www.scopus.com/inward/record.url?scp=0034691114&partnerID=8YFLogxK
U2 - 10.1073/pnas.97.13.7603
DO - 10.1073/pnas.97.13.7603
M3 - Article
C2 - 10861022
AN - SCOPUS:0034691114
SN - 0027-8424
VL - 97
SP - 7603
EP - 7608
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 13
ER -