Abstract
Measuring cerebral oxygen delivery and metabolism microscopically is important for interpreting macroscopic functional magnetic resonance imaging (fMRI) data and identifying pathological changes associated with stroke, Alzheimer's disease, and brain injury. Here, we present simultaneous, microscopic measurements of cerebral blood flow (CBF) and oxygen partial pressure (pO2) in cortical microvessels of anesthetized rats under baseline conditions and during somatosensory stimulation. Using a custom-built imaging system, we measured CBF with Fourier-domain optical coherence tomography (OCT), and vascular pO2 with confocal phosphorescence lifetime microscopy. Cerebral blood flow and pO2 measurements displayed heterogeneity over distances irresolvable with fMRI and positron emission tomography. Baseline measurements indicate O2 extraction from pial arterioles and homogeneity of ascending venule pO2 despite large variation in microvessel flows. Oxygen extraction is linearly related to flow in ascending venules, suggesting that flow in ascending venules closely matches oxygen demand of the drained territory. Oxygen partial pressure and relative CBF transients during somatosensory stimulation further indicate arteriolar O 2 extraction and suggest that arterioles contribute to the fMRI blood oxygen level dependent response. Understanding O2 supply on a microscopic level will yield better insight into brain function and the underlying mechanisms of various neuropathologies.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1051-1063 |
| Number of pages | 13 |
| Journal | Journal of Cerebral Blood Flow and Metabolism |
| Volume | 31 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1 2011 |
| Externally published | Yes |
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Keywords
- cerebral blood flow
- fMRI
- microscopy
- optical imaging
- oxygen
ASJC Scopus subject areas
- Neurology
- Clinical Neurology
- Cardiology and Cardiovascular Medicine
Cite this
Microvascular oxygen tension and flow measurements in rodent cerebral cortex during baseline conditions and functional activation. / Yaseen, Mohammad A.; Srinivasan, Vivek; Sakadžić, Sava; Radhakrishnan, Harsha; Gorczynska, Iwona; Wu, Weicheng; Fujimoto, James G.; Boas, David A.
In: Journal of Cerebral Blood Flow and Metabolism, Vol. 31, No. 4, 01.04.2011, p. 1051-1063.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Microvascular oxygen tension and flow measurements in rodent cerebral cortex during baseline conditions and functional activation
AU - Yaseen, Mohammad A.
AU - Srinivasan, Vivek
AU - Sakadžić, Sava
AU - Radhakrishnan, Harsha
AU - Gorczynska, Iwona
AU - Wu, Weicheng
AU - Fujimoto, James G.
AU - Boas, David A.
PY - 2011/4/1
Y1 - 2011/4/1
N2 - Measuring cerebral oxygen delivery and metabolism microscopically is important for interpreting macroscopic functional magnetic resonance imaging (fMRI) data and identifying pathological changes associated with stroke, Alzheimer's disease, and brain injury. Here, we present simultaneous, microscopic measurements of cerebral blood flow (CBF) and oxygen partial pressure (pO2) in cortical microvessels of anesthetized rats under baseline conditions and during somatosensory stimulation. Using a custom-built imaging system, we measured CBF with Fourier-domain optical coherence tomography (OCT), and vascular pO2 with confocal phosphorescence lifetime microscopy. Cerebral blood flow and pO2 measurements displayed heterogeneity over distances irresolvable with fMRI and positron emission tomography. Baseline measurements indicate O2 extraction from pial arterioles and homogeneity of ascending venule pO2 despite large variation in microvessel flows. Oxygen extraction is linearly related to flow in ascending venules, suggesting that flow in ascending venules closely matches oxygen demand of the drained territory. Oxygen partial pressure and relative CBF transients during somatosensory stimulation further indicate arteriolar O 2 extraction and suggest that arterioles contribute to the fMRI blood oxygen level dependent response. Understanding O2 supply on a microscopic level will yield better insight into brain function and the underlying mechanisms of various neuropathologies.
AB - Measuring cerebral oxygen delivery and metabolism microscopically is important for interpreting macroscopic functional magnetic resonance imaging (fMRI) data and identifying pathological changes associated with stroke, Alzheimer's disease, and brain injury. Here, we present simultaneous, microscopic measurements of cerebral blood flow (CBF) and oxygen partial pressure (pO2) in cortical microvessels of anesthetized rats under baseline conditions and during somatosensory stimulation. Using a custom-built imaging system, we measured CBF with Fourier-domain optical coherence tomography (OCT), and vascular pO2 with confocal phosphorescence lifetime microscopy. Cerebral blood flow and pO2 measurements displayed heterogeneity over distances irresolvable with fMRI and positron emission tomography. Baseline measurements indicate O2 extraction from pial arterioles and homogeneity of ascending venule pO2 despite large variation in microvessel flows. Oxygen extraction is linearly related to flow in ascending venules, suggesting that flow in ascending venules closely matches oxygen demand of the drained territory. Oxygen partial pressure and relative CBF transients during somatosensory stimulation further indicate arteriolar O 2 extraction and suggest that arterioles contribute to the fMRI blood oxygen level dependent response. Understanding O2 supply on a microscopic level will yield better insight into brain function and the underlying mechanisms of various neuropathologies.
KW - cerebral blood flow
KW - fMRI
KW - microscopy
KW - optical imaging
KW - oxygen
UR - http://www.scopus.com/inward/record.url?scp=79953283190&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79953283190&partnerID=8YFLogxK
U2 - 10.1038/jcbfm.2010.227
DO - 10.1038/jcbfm.2010.227
M3 - Article
VL - 31
SP - 1051
EP - 1063
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
SN - 0271-678X
IS - 4
ER -