Genetic tools for imaging microcirculation via plasma labeling.

Cerebral microcirculation is a critical infrastructure for brain function, delivering energy substrates and clearing metabolic byproducts. Disruptions in vascular dynamics contribute to neurodegenerative diseases, stroke, and cognitive impairments. Traditional blood labeling methods for fluorescence imaging, such as fluorescent dextran injection, have advanced our understanding of microcirculation but are limited for long-term imaging. In this mini review, we introduce two recently developed molecular genetic techniques, achieved by recombinant adeno-associated virus (AAV)-mediated plasma label expression or genomic knock-in that enable stable, long-term microcirculation imaging. These AAV-mediated methods require only a single systemic injection, facilitating longitudinal imaging of microcirculation in mouse models of disease. We discuss the fundamental design concepts of these approaches and explore their potential applications in systems biology.