Optical measurement of microvascular oxygenation and blood flow responses in awake mouse cortex during functional activation

Published on 2020-08-01T14:06:16Z (GMT) by
<div><p>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 O<sub>2</sub> metabolism and/or laminar variability in both O<sub>2</sub> demand and hemodynamic response. Here, we investigate the laminar profile of stimulus-induced intravascular partial pressure of O<sub>2</sub> (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 pO<sub>2</sub> are conserved across cortical layers I–IV, suggesting a tightly controlled neurovascular response to provide adequate O<sub>2</sub> supply across cortical depth. In addition, we observed a larger change in venular O<sub>2</sub> saturation (ΔsO<sub>2</sub>) compared to arterioles, a gradual increase in venular ΔsO<sub>2</sub> 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 O<sub>2</sub> 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.</p></div>

Cite this collection

Şencan, İkbal; Esipova, Tatiana; Kılıç, Kıvılcım; Li, Baoqiang; Desjardins, Michèle; Yaseen, Mohammad A; et al. (2020): Optical measurement of microvascular oxygenation and blood flow responses in awake mouse cortex during functional activation. SAGE Journals. Collection. https://doi.org/10.25384/SAGE.c.5080169.v1