Figure 1. A schematic diagram illustrating the constituents of
the CNS barriers. The endothelial cells are connected by tight junctions
(TJs), preventing molecules permeating from the blood into the CNS
parenchyma via the paracellular route. Influx transporters such as
L-type amino acid transporter 1 (LAT1) and glucose transporter 1 (GLUT1)
facilitate entry of nutrients into the parenchyma, whereas efflux
transporters such as P-glycoprotein (P-gp) and breast cancer resistance
protein (BCRP) actively exclude potential toxins from entering the
brain. |