| Brain tissue oxygen consumption and supply induced by neural activation: determined under suppressed hemodynamic response conditions in the anesthetized rat cerebral cortex. | |
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MedLine Citation:
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PMID: 19227484 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The dynamic changes in cerebral metabolic rate of oxygen (CMRO2) and oxygen supply during brain functions have not been well-characterized. To examine this issue, experiments with electrophysiology, oxygen microelectrode and laser-Doppler flowmetry were performed in the anesthetized rat somatosensory cortex. During neural activation, brain tissue partial pressure of oxygen (P(O2)) and local cerebral blood flow (CBF) were similarly increased. To separate the P(O2) changes originating from the increase in CMRO2 and the increase in oxygen supply, the same experiments were repeated under a vasodilator-induced hypotension condition in which evoked CBF change was minimal. In this condition, evoked P(O2) monotonically decreased, indicating an increase in CMRO2. Then, CMRO2 was determined at resting as well as activation periods using a dynamic oxygen exchange model. Our results indicated that the changes in CMRO2 were linearly related with the summation of evoked field potentials and further showed that the oxygen supply in the normal condition was about 2.5 times larger than the demand. However, this oxygen oversupply was not explainable by the change in CBF alone, but at least partly by the increase in oxygenation levels at pre-capillary arterioles (e.g., 82% to 90% O2 saturation level) when local neural activity was evoked. |
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Authors:
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Kazuto Masamoto; Alberto Vazquez; Ping Wang; Seong-Gi Kim |
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Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Advances in experimental medicine and biology Volume: 645 ISSN: 0065-2598 ISO Abbreviation: Adv. Exp. Med. Biol. Publication Date: 2009 |
Date Detail:
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Created Date: 2009-02-19 Completed Date: 2009-03-11 Revised Date: 2010-12-03 |
Medline Journal Info:
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Nlm Unique ID: 0121103 Medline TA: Adv Exp Med Biol Country: United States |
Other Details:
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Languages: eng Pagination: 287-92 Citation Subset: IM |
Affiliation:
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National Institute of Radiological Sciences, Molecular Imaging Center, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan. masamoto@nirs.go.jp |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Anesthesia* Animals Cerebral Cortex / blood supply*, drug effects, metabolism* Male Oxygen / metabolism* Oxygen Consumption / drug effects* Rats Rats, Sprague-Dawley |
| Grant Support | |
ID/Acronym/Agency:
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EB003375/EB/NIBIB NIH HHS; F32 NS056682-02/NS/NINDS NIH HHS; NS044589/NS/NINDS NIH HHS |
| Chemical | |
Reg. No./Substance:
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7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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