Cortical capillary blood flow and oxygenation are highly heterogeneous. Mapping absolute capillary blood flow and oxygenation along capillary path is a key step towards understanding how oxygen is transported and delivered in a complex microvascular network to enable adequate tissue oxygenation. In this work, we applied two-photon microscopic imaging of intravascular oxygen partial pressure (PO2) to measure both oxygen concentration and red blood cell (RBC) flux in cortical arterioles, capillaries, and venules. Imaging was performed in awake, head-restrained C57BL/6 mice (n=15), through a chronic sealed cranial window centered over the E1 whisker barrel. We obtained a detailed mapping of the resting state cortical microvascular PO2 in all arterioles and venules, and both PO2 and RBC flux in most capillaries down to 600 μm depth from the cortical surface (n=6,544 capillaries across all mice). Capillary RBC speed and density were also extracted and all measurements were co-registered with the microvascular angiograms. We characterized the distributions of capillary PO2 and flow as a function of branching order and cortical depth. The results show strong positive correlation between oxygenation and flow in the capillary segments, with an increased correlation in downstream capillaries. We have also observed homogenization of both oxygenation and flow in deeper cortical layers, which may imply a mechanism to improve oxygen delivery without increasing global blood flow in the area with increased metabolism.
Baoqiang Li, Ikbal Sencan, Tatiana V. Esipova, Kivilcim Kilic, Mohammad Moeini, Mohammad A. Yaseen, Buyin Fu, Sreekanth Kura, Frédéric Lesage, Sergei A. Vinogradov, Anna Devor, David A. Boas, and Sava Sakadžić, "Cerebral oxygenation and blood flow distributions along the capillary path in awake mice (Conference Presentation)," Proc. SPIE 10481, Neural Imaging and Sensing 2018, 1048109 (Presented at SPIE BiOS: January 29, 2018; Published: 14 March 2018); https://doi.org/10.1117/12.2290858.5751476102001.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the conference proceedings. They include the speaker's narration along with a video recording of the presentation slides and animations. Many conference presentations also include full-text papers. Search and browse our growing collection of more than 12,000 conference presentations, including many plenary and keynote presentations.