Figure 1.

The vascular network is a scaffold for glymphatic fluid transport along the perivascular spaces. Glymphatic fluid (light blue) enters the brain via the perivascular space of the major arteries (red; left). Arteries and veins are lined by perivascular spaces, where astrocyte end feet (green) cover smooth muscle cells (gray) and the endothelial wall of the vasculature (pink; right). This perivascular unit is a critical component of the glymphatic system, and its geometry is biologically optimized to promote fluid movement (blue arrows).