Fig. 1

The Neurovascular Unit. The neurovascular unit is the multifaceted structure in the brain that facilitates blood supply, metabolic waste clearance and protection from potentially harmful peripheral material. From inwards to outwards, it is comprised of the artery which supplies blood, the endothelial cell and tight junctions that form the blood–brain barrier, the perivascular space which supports glymphatic waste clearance, and the astrocytes that synapse onto parenchymal neurons and host aquaporin-4 (AQP4) channels that facilitate fluid exchange. Adapted with permission from Sun et al. [157]