title: Temporal dynamics of the partial pressure of brain tissue oxygen during functional forepaw stimulation in rats.
abstract: The partial pressure of tissue oxygen (pO2) was measured in rat somatosensory cortex during periodic electrical forepaw stimulation of either 1 min or 4 s in duration, and correlated with simultaneous laser Doppler flowmetry. For both stimulus durations, a transient decrease in tissue pO2 preceded blood flow changes, followed by a peak in blood flow and an overshoot in tissue pO2. With protracted stimulation, tissue pO2 remained only slightly above pre-stimulus baseline, while blood flow was maintained at a reduced plateau phase. A sustained post-stimulus undershoot in tissue pO2 was observed only for the 1 min stimulus. These findings suggest a complex dynamic relationship between oxygen utilization and blood flow.
authors.affiliation: Department of Neurology, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: Ances
authors.forename: D G
authors.initials: DG
authors.lastname: Buerk
authors.forename: J H
authors.initials: JH
authors.lastname: Greenberg
authors.forename: J A
authors.initials: JA
authors.lastname: Detre
mesh_terms: D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004558:Electric Stimulation; D005552:Forelimb / Q000294:innervation / Q000502:physiology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology; D008839:Microelectrodes; D009474:Neurons / Q000378:metabolism; D017711:Nonlinear Dynamics; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D010313:Partial Pressure; D010812:Physical Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013003:Somatosensory Cortex / Q000166:cytology / Q000378:metabolism*; D013997:Time Factors
chemical_list: D010100:Oxygen