fig1

Figure 1. The components of BBB, NGVU, and the glymphatic system. The NGVU is composed of neuronal cells, glial cells, and the vascular system that includes arteries, veins, smooth muscle cells (not depicted in the figure), and pericytes that encircle the vascular endothelial cells. The glymphatic system is primarily made up of astrocytes and the endfeet of astrocytes that envelop the vasculature. It drains waste products through the CSF from the artery, flowing into the ISF through astrocytic AQP4 channels, thereby mixing the CSF with ISF. Waste solutes and/or by-products subsequently traverse the glymphatic pathway for absorption and processing by the waste clearance system.