Molecular architecture of the brain microvasculature: perspective on blood-brain transport.

Brain endothelial cells and their intercellular tight junctions form a cellular interface between the circulating blood and neural environment. All nutrients consumed by brain must traffic through this cellular space and its two limiting membranes. Additionally, the endothelial cell affects homeostasis by contributing or removing constituents from the interstitial space. These endothelial-cell functions are collectively accomplished with a rich complement of transporters and channels distributed, frequently asymmetrically, between the luminal and abluminal membranes. The identity and characterization of these proteins is rapidly advancing by application of molecular and cellular techniques. Knowledge of these molecular mechanisms will be beneficial in improving brain function and the treatment of neurological diseases.