Oxygen imaging of hypoxic pockets in the mouse cerebral cortex

Abstract

Consciousness is lost within seconds upon cessation of cerebral blood flow. The brain cannot store oxygen, and interruption of oxidative phosphorylation is fatal within minutes. Yet only rudimentary knowledge exists regarding cortical partial oxygen tension ( P o 2 ) dynamics under physiological conditions. Here we introduce Green enhanced Nano-lantern (GeNL), a genetically encoded bioluminescent oxygen indicator for P o 2 imaging. In awake behaving mice, we uncover the existence of spontaneous, spatially defined “hypoxic pockets” and demonstrate their linkage to the abrogation of local capillary flow. Exercise reduced the burden of hypoxic pockets by 52% compared with rest. The study provides insight into cortical oxygen dynamics in awake behaving animals and concurrently establishes a tool to delineate the importance of oxygen tension in physiological processes and neurological diseases.

Modal Analysis of Cerebrovascular Effects for Digital Health Integration of Neurostimulation Therapies—A Review of Technology Concepts

“…There are various neurostimulation approaches to facilitate CBF: Animal studies have revealed the presence of spontaneous “hypoxic pockets” in the brains of awake, active mice, linked to interruptions in the local capillary flow [ 82 ]. Moreover, it was found that exercise reduced these hypoxic areas by 52% compared to when at rest.…”