Hemodynamic maps of the pial vascular connectome
The pial vasculature is the sole source of blood supply to the neocortex. The brain is con-tained within the skull, a vascularized bone marrow with a unique anatomical connectionto the brain meninges. Recent developments in tissue clearing have enabled detailedmapping of the entire pial and calvarial vasculature. However, what are the absoluteflow rate values of those vascular networks? This information cannot accurately beretrieved with the commonly used bioimaging methods. Here, we introduce Pia-FLOW,a unique approach based on large-scale transcranial fluorescence localization microscopy,to attain hemodynamic imaging of the whole murine pial and calvarial vasculature atframe rates up to 1,000 Hz and spatial resolution reaching 5.4 µm. Using Pia-FLOW,we provide detailed maps of flow velocity, direction, and vascular diameters which canserve as ground-truth data for further studies, advancing our understanding of brain fluiddynamics. Furthermore, Pia-FLOW revealed that the pial vascular network functionsas one unit for robust allocation of blood after stroke.