Measurement of cerebral oxygen pressure in living mice by two-photon phosphorescence lifetime microscopy

• Published in: STAR protocols 2022-06, Vol.3 (2), p.101370, Article 101370
• Main Authors: Erlebach, Eva, Ravotto, Luca, Wyss, Matthias T., Condrau, Jacqueline, Troxler, Thomas, Vinogradov, Sergei A., Weber, Bruno
• Format: Article
• Language: English
• Subjects: Animals; Cerebral Cortex - diagnostic imaging; Metabolism; Mice; Microscopy; Microscopy - methods; Model Organisms; Molecular/Chemical Probes; Neuroscience; Oxygen - metabolism; Partial Pressure; Photons; Protocol
• ISSN: 2666-1667; 2666-1667
• DOI: 10.1016/j.xpro.2022.101370

The ability to quantify partial pressure of oxygen (pO2) is of primary importance for studies of metabolic processes in health and disease. Here, we present a protocol for imaging of oxygen distributions in tissue and vasculature of the cerebral cortex of anesthetized and awake mice. We describe in vivo two-photon phosphorescence lifetime microscopy (2PLM) of oxygen using the probe Oxyphor 2P. This minimally invasive protocol outperforms existing approaches in terms of accuracy, resolution, and imaging depth. For complete details on the use and execution of this protocol, please refer to Esipova et al. (2019). [Display omitted] •Two-photon phosphorescence imaging of Oxyphor 2P allows for oxygen measurement in vivo•Oxygen imaging can be performed in anesthetized or awake, behaving mice•Intravenous injection enables oxygen imaging in the vasculature•Cisterna magna injection enables extra- and intravascular oxygen imaging in the brain Publisher's note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics. The ability to quantify partial pressure of oxygen (pO2) is of primary importance for studies of metabolic processes in health and disease. Here, we present a protocol for imaging of oxygen distributions in tissue and vasculature of the cerebral cortex of anesthetized and awake mice. We describe in vivo two-photon phosphorescence lifetime microscopy (2PLM) of oxygen using the probe Oxyphor 2P. This minimally invasive protocol outperforms existing approaches in terms of accuracy, resolution, and imaging depth.