Blood–brain barrier
| Blood–brain barrier | |
|---|---|
Solute permeability at the BBB vs. choroid plexus | |
| Details | |
| System | Neuroimmune system |
| Identifiers | |
| Acronym(s) | BBB |
| MeSH | D001812 |
| Anatomical terminology | |
The blood–brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system, thus protecting the brain from harmful or unwanted substances in the blood.[1] The blood–brain barrier is formed by endothelial cells of the capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane.[2] This system allows the passage of some small molecules by passive diffusion, as well as the selective and active transport of various nutrients, ions, organic anions, and macromolecules such as glucose and amino acids that are crucial to neural function.[3]
The blood–brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and large or hydrophilic molecules into the cerebrospinal fluid, while allowing the diffusion of hydrophobic molecules (O2, CO2, hormones) and small non-polar molecules.[4][5] Cells of the barrier actively transport metabolic products such as glucose across the barrier using specific transport proteins.[6] The barrier also restricts the passage of peripheral immune factors, like signaling molecules, antibodies, and immune cells, into the central nervous system, thus insulating the brain from damage due to peripheral immune events.[7]
Specialized brain structures participating in sensory and secretory integration within brain neural circuits—the circumventricular organs and choroid plexus—have in contrast highly permeable capillaries.[8]
- ^ Daneman R, Prat A (January 2015). "The blood-brain barrier". Cold Spring Harbor Perspectives in Biology. 7 (1): a020412. doi:10.1101/cshperspect.a020412. PMC 4292164. PMID 25561720.
- ^ Ballabh P, Braun A, Nedergaard M (June 2004). "The blood-brain barrier: an overview: structure, regulation, and clinical implications". Neurobiology of Disease. 16 (1): 1–13. doi:10.1016/j.nbd.2003.12.016. PMID 15207256. S2CID 2202060.
- ^ Gupta S, Dhanda S, Sandhir R (2019). "Anatomy and physiology of blood-brain barrier". In Gao H, Gao X (eds.). Brain Targeted Drug Delivery System. Academic Press. pp. 7–31. doi:10.1016/b978-0-12-814001-7.00002-0. ISBN 978-0-12-814001-7. S2CID 91847478. Retrieved 2023-11-02.
- ^ Obermeier B, Daneman R, Ransohoff RM (December 2013). "Development, maintenance and disruption of the blood-brain barrier". Nature Medicine. 19 (12): 1584–96. doi:10.1038/nm.3407. PMC 4080800. PMID 24309662.
- ^ Kadry H, Noorani B, Cucullo L (November 2020). "A blood-brain barrier overview on structure, function, impairment, and biomarkers of integrity". Fluids Barriers CNS. 17 (1) 69. doi:10.1186/s12987-020-00230-3. PMC 7672931. PMID 33208141.
- ^ Stamatovic SM, Keep RF, Andjelkovic AV (September 2008). "Brain endothelial cell-cell junctions: how to "open" the blood brain barrier". Current Neuropharmacology. 6 (3): 179–92. doi:10.2174/157015908785777210. PMC 2687937. PMID 19506719.
- ^ Muldoon LL, Alvarez JI, Begley DJ, Boado RJ, Del Zoppo GJ, Doolittle ND, et al. (January 2013). "Immunologic privilege in the central nervous system and the blood-brain barrier". Journal of Cerebral Blood Flow and Metabolism. 33 (1): 13–21. doi:10.1038/jcbfm.2012.153. PMC 3597357. PMID 23072749.
- ^ Kaur C, Ling EA (September 2017). "The circumventricular organs". Histology and Histopathology. 32 (9): 879–892. doi:10.14670/HH-11-881. PMID 28177105.