Measurement of Cerebrovascular Hemodynamics in Awake Freely Behaving Mice

Abstract

Hemodynamic changes are frequently used as a readout for neuronal activity in functional imaging studies, and the mechanisms by which neurons communicate activity‐dependent energy needs to the surrounding vasculature to evoke an increase in blood flow (functional hyperemia) are collectively termed neurovascular coupling (NVC). Various techniques are utilized to measure the hemodynamic changes resulting from NVC but none provide precise, cellular resolution data in awake and freely behaving animals. Here, we repurpose novel in‐vivo imaging technology to measure brain blood flow at the single capillary level using miniature head mounted microscopes (miniscopes) and compare this to gold‐standard multiphoton imaging of blood flow. We combine the use of miniscopes for data collection with automated analyses for rapid, accurate and impartial assessment of blood flow through complex vascular networks in deep brain structures. By adapting miniscopes to study hemodynamics in detail, we aim to generate high‐resolution data of NVC and functional hyperemia that provides a window into the dynamics of these mechanisms in awake, freely behaving animals.