The blood-brain barrier (BBB) is a highly selective, semipermeable border that separates the circulating blood from the brain and extracellular fluid in the central nervous system (CNS). Composed of endothelial cells with tight junctions, astrocyte end-feet, and pericytes, the BBB plays a crucial role in maintaining the brain’s microenvironment. It restricts the passage of pathogens, toxins, and large or hydrophilic molecules while allowing essential nutrients and gases to pass through.
Read more