Blood-Brain Barrier and “brain drain”

Question 1

What is the function of the Blood-Brain Barrier?

Answer 1

Physical and functional barrier between circulating blood, the central nervous system and cerebrospinal fluid

Question 2

What are the 3 ways the Blood-Brain Barrier maintains homeostasis through system of cellular transport mechanisms?

Answer 2

• Restricts entrances of harmful agencies from the blood
• Permeable for essential CNS nutrients
• Protects sensitive neurons from environmental changes

Question 3

How do lymphocytes access and exit the brain?

Answer 3

Through the meningeal lymphatic system

Question 4

What are the 3 steps for Blood-Brain Barrier breakdown in the CNS pathology and what happens in each step?

Answer 4

1. Endothelium activation: leukocyte crawling and adhesion (selectins and integrins) => increased BBB permeability
2. Formation of perivascular cuffs: BBB breakdown => leukocyte transmigration (chemokines) and accumulation
3. Parenchyme invasion: parenchymal basement membrane breeched => leukocyte extravasation, activation and migration

Question 5

What are the 3 ways Imatinib treats EAE?

Answer 5

Preserves BBB integrity:

• reduces amount of recruited inflammarory cells to the CNS
• decreases endothelial cell activation at the BBB
• preserves tight junctions at the BBB