Introducing the brain: strict blood-brain barrier (Introduction)

by David Turell , Monday, February 10, 2020, 19:35 (1530 days ago) @ David Turell

The brain is very different from all other organs. It is delicate and requires precise protection, but it needs oxygen and glucose and get rid of waste products and CO2 like the other organs:

https://phys.org/news/2020-02-human-brain-meticulous-interface-bloodstream.html

"The brain is the only part of the body outfitted with astrocytes, which regulate nourishment uptake and waste removal in their own, unique way.

"'Upon the brain's request, astrocytes collaborate with the vasculature in real-time what the brain needs and opens its gates to let in only that bit of water and nutrients. Astrocytes go to get just what the brain needs and don't let much else in," Kim said.

"Astrocytes form a protein structure called aquaporin-4 in their membranes that are in contact with vasculature to let in and out water molecules, which also contributes to clearing waste from the brain.

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"In testing related to drug delivery, nanoparticles moved through the blood-brain-barrier after engaging endothelial cell receptors, which caused these cells to engulf the particles then transport them to what would be inside the human brain in a natural setting. "

Comment: A beautiful example of design. I would guess the first evolved brains had this barrier with its very specialized protein complex..