Blood-brain barrier and cellular membranes (BBB)

The blood-brain barrier (BBB) and cellular membranes are critical physiological structures that regulate the internal environment of cells and the central nervous system. The BBB is a highly specialized microvascular system composed of endothelial cells connected by tight junctions, which, along with pericytes and astrocytic endfeet, restricts the passage of most molecules from the blood into the brain parenchyma (Abbott et al., 2010, Nature Reviews Neuroscience). Cellular membranes consist of a phospholipid bilayer embedded with proteins that facilitate communication and transport, maintaining the integrity and function of individual cells (Alberts et al., 2002, Molecular Biology of the Cell). While not a single molecular target, these membranes are central to pharmacology as they dictate drug bioavailability and distribution; for instance, the BBB prevents over 98% of small-molecule drugs from reaching the brain (Pardridge, 2005, NeuroRx). Pathological breakdown of these barriers is associated with neurodegenerative diseases, stroke, and infections, making their modulation a key area of therapeutic research (Zlokovic, 2011, Nature Reviews Neuroscience).

Other names

Blood-brain interfaceNeurovascular unitPlasma membraneCytoplasmic membraneBiological membrane

Drugs interact with these structures through osmotic disruption of tight junctions, physical disruption of the phospholipid bilayer, or modulation of membrane-bound efflux transporters and receptors to alter permeability (Pardridge, 2005, NeuroRx; Daneman & Prat, 2015, Cold Spring Harbor Perspectives in Biology).