Bm. Ances et al., Temporal dynamics of the partial pressure of brain tissue oxygen during functional forepaw stimulation in rats, NEUROSCI L, 306(1-2), 2001, pp. 106-110
The partial pressure of tissue oxygen (pO(2)) was measured in rat somatosen
sory cortex during periodic electrical forepaw stimulation of either 1 min
or 4 s in duration, and correlated with simultaneous laser Doppler flowmetr
y. For both stimulus durations, a transient decrease in tissue pO(2) preced
ed blood flow changes, followed by a peak in blood flow and an overshoot in
tissue pO(2) With protracted stimulation, tissue pO(2) remained only sligh
tly above pre-stimulus baseline, while blood flow was maintained at a reduc
ed plateau phase. A sustained post-stimulus undershoot in tissue pO(2) was
observed only for the 1 min stimulus. These findings suggest a complex dyna
mic relationship between oxygen utilization and blood flow. (C) 2001 Elsevi
er Science Ireland Ltd. All rights reserved.