Blood Brain Barrier

Question 1

What were the initial perceptions of the blood brain barrier?

Answer 1

Acid dyes were excluded from the greater part of the CNS
Thought to be because nerve cells had failed to internalise the dye
Later established there must be a barrier between the brain and the blood

Question 2

Where is the BBB?

Answer 2

Demonstrated to be at the tight junctions of the vascular endothelium in the CNS vessels by Reese and Karnovsky in 1967