blood-brain barrier

noun

ˈbləd-ˈbrān- 

: a naturally occurring barrier created by the modification of brain capillaries (as by reduction in fenestration and formation of tight cell-to-cell contacts) that prevents many substances from leaving the blood and crossing the capillary walls into the brain tissues

Examples of blood-brain barrier in a Sentence

Recent Examples on the Web

This could allow therapies that were previously ineffective — due to their inability to cross the blood-brain barrier to reach their target in the central nervous system — to directly target tissues. —Melissa Rudy, Fox News, 31 Dec. 2024

Research on microplastics in the body is still new, and whether these microscopic bits of plastic can pass through the blood-brain barrier in humans is still a big question. —Kaitlin Sullivan, NBC News, 16 Sep. 2024

Consuming tryptophan with carbohydrates allows more to cross the blood-brain barrier, resulting in greater melatonin production.11 10. —Amy Brownstein, Ms, Rdn, Verywell Health, 16 Dec. 2024

One of the most influential researchers on the role of the blood-brain barrier in stroke and Alzheimer’s, Zlokovic was the only common author across the 37 papers, and the senior author on 29. —Bycharles Piller, science.org, 8 Nov. 2024

Word History

First Known Use

1934, in the meaning defined above

Medical Definition

blood-brain barrier

noun

: a naturally occurring barrier created by the modification of brain capillaries (as by reduction in fenestration and formation of tight cell-to-cell contacts) that prevents many substances from leaving the blood and crossing the capillary walls into the brain tissues

—abbreviation BBB