What is the Blood-Brain Barrier? It is a highly selective semipermeable border that separates the circulating blood from the brain and central nervous system (CNS). It is composed of specialized cells that tightly regulate the movement of substances between the blood and the brain to maintain a stable environment for proper neuronal function.
The BBB allows essential nutrients, such as oxygen and glucose, to pass through to the brain while preventing potentially harmful substances, like toxins and pathogens, from entering. It also helps to maintain a consistent chemical composition in the brain by selectively allowing certain molecules to cross.
The barrier is formed by a layer of endothelial cells that line the capillaries in the brain, surrounded by pericytes and astrocytes. These cells work together to restrict the passage of most molecules, including large proteins and hydrophilic (water-soluble) substances, into the brain.
The blood-brain barrier plays a crucial role in protecting the brain from potential harm and maintaining its proper functioning. It is an essential feature of the central nervous system and understanding its function is important for developing treatments for brain disorders and delivering drugs to the brain.
Reference
Daneman, R., & Prat, A. (2015). The blood-brain barrier. Cold Spring Harbor perspectives in biology, 7(1), a020412. https://doi.org/10.1101/cshperspect.a020412
