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

TitleOptical measurement of microvascular oxygenation and blood flow responses in awake mouse cortex during functional activation.
Publication TypeJournal Article
Year of Publication2020
AuthorsŞencan, İ, Esipova, T, Kılıç, K, Li, B, Desjardins, M, Yaseen, MA, Wang, H, Porter, JE, Kura, S, Fu, B, Secomb, TW, Boas, DA, Vinogradov, SA, Devor, A, Sakadžić, S
JournalJ Cereb Blood Flow Metab
Pagination271678X20928011
Date Published2020 Jun 09
ISSN1559-7016
Abstract

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 metabolism and/or laminar variability in both O demand and hemodynamic response. Here, we investigate the laminar profile of stimulus-induced intravascular partial pressure of O (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 are conserved across cortical layers I-IV, suggesting a tightly controlled neurovascular response to provide adequate O supply across cortical depth. In addition, we observed a larger change in venular O saturation (ΔsO) compared to arterioles, a gradual increase in venular ΔsO 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 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.

DOI10.1177/0271678X20928011
Alternate JournalJ Cereb Blood Flow Metab
PubMed ID32515672
Grant ListP01 NS055104 / NS / NINDS NIH HHS / United States