TY - JOUR
T1 - Optical measurement of microvascular oxygenation and blood flow responses in awake mouse cortex during functional activation
AU - Şencan, İkbal
AU - Esipova, Tatiana
AU - Kılıç, Kıvılcım
AU - Li, Baoqiang
AU - Desjardins, Michèle
AU - Yaseen, Mohammad A.
AU - Wang, Hui
AU - Porter, Jason E.
AU - Kura, Sreekanth
AU - Fu, Buyin
AU - Secomb, Timothy W.
AU - Boas, David A.
AU - Vinogradov, Sergei A.
AU - Devor, Anna
AU - Sakadžić, Sava
N1 - Publisher Copyright:
© The Author(s) 2020.
PY - 2022/3
Y1 - 2022/3
N2 - The cerebral cortex has a number of conserved morphological and functional characteristics across brain regions and species. Among them, the laminar differences in microvascular density and mitochondrial cytochrome c oxidase staining suggest potential laminar variability in the baseline O2 metabolism and/or laminar variability in both O2 demand and hemodynamic response. Here, we investigate the laminar profile of stimulus-induced intravascular partial pressure of O2 (pO2) transients to stimulus-induced neuronal activation in fully awake mice using two-photon phosphorescence lifetime microscopy. Our results demonstrate that stimulus-induced changes in intravascular pO2 are conserved across cortical layers I–IV, suggesting a tightly controlled neurovascular response to provide adequate O2 supply across cortical depth. In addition, we observed a larger change in venular O2 saturation (ΔsO2) compared to arterioles, a gradual increase in venular ΔsO2 response towards the cortical surface, and absence of the intravascular “initial dip” previously reported under anesthesia. This study paves the way for quantification of layer-specific cerebral O2 metabolic responses, facilitating investigation of brain energetics in health and disease and informed interpretation of laminar blood oxygen level dependent functional magnetic resonance imaging signals.
AB - The cerebral cortex has a number of conserved morphological and functional characteristics across brain regions and species. Among them, the laminar differences in microvascular density and mitochondrial cytochrome c oxidase staining suggest potential laminar variability in the baseline O2 metabolism and/or laminar variability in both O2 demand and hemodynamic response. Here, we investigate the laminar profile of stimulus-induced intravascular partial pressure of O2 (pO2) transients to stimulus-induced neuronal activation in fully awake mice using two-photon phosphorescence lifetime microscopy. Our results demonstrate that stimulus-induced changes in intravascular pO2 are conserved across cortical layers I–IV, suggesting a tightly controlled neurovascular response to provide adequate O2 supply across cortical depth. In addition, we observed a larger change in venular O2 saturation (ΔsO2) compared to arterioles, a gradual increase in venular ΔsO2 response towards the cortical surface, and absence of the intravascular “initial dip” previously reported under anesthesia. This study paves the way for quantification of layer-specific cerebral O2 metabolic responses, facilitating investigation of brain energetics in health and disease and informed interpretation of laminar blood oxygen level dependent functional magnetic resonance imaging signals.
KW - Intravascular partial pressure of oxygen
KW - cortical layers
KW - neurovascular coupling
KW - oxygen extraction fraction
KW - two-photon microscopy
UR - http://www.scopus.com/inward/record.url?scp=85086171675&partnerID=8YFLogxK
U2 - 10.1177/0271678X20928011
DO - 10.1177/0271678X20928011
M3 - Article
C2 - 32515672
AN - SCOPUS:85086171675
SN - 0271-678X
VL - 42
SP - 510
EP - 525
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
IS - 3
ER -