Blood Brain Barrier

what dye was used to reveal the idea of the blood brain barrier?

trypan blue

What does the blood brain barrier consist of?

a wall of brain capillaries

how many arteries supply the brain with oxygen?

4

name the two types of arteries that supply the brain with oxygen

x2 carotid artery
x2 vertebral artery

What is the Circle of Willis?

A circle of the 4 arteries that supply blood to the brain

what does India ink stain?

vascular system

what is the capillary density of the human brain?

2500-3000/mm3

walls of blood vessels are composed of ...?

endothelial cells (monolayer/single cell)

what can be used to identify astrocytes?

GFAP- glial fibrillary acidic protein staining

where are glial limitans located

surface of the brain

can astrocytes form more than one endfoot?

ys

what component of astrocytes contains water channels?

aquaporin

what is the process which materials move through the endothelial membrane?

passive diffusion

name 5 permeation mechansims

1) simple diffusion
2) passive diff
3) transporter influx
4) transporter efflux
5) endocytosis

Where are adherens junctions found?

between capillaries

what structure between cells restrict movement of molecules?

tight junctions

what are the 2 transmembrane proteins that make up adheren junction?

PECAM and VE

transmembrane proteins of the tight and adheren juctions are separated, true or false?

false- they are interlinked

what are the transmembrane proteins of tight junctions?

ZO, JAM, ESAM

where is electrical resistance higher, in the brain or peripheral capillaries?

much higher in the brain

why is it difficult for morphine to cross the BBB

low lipophilicity due to presence of -OH groups

Why is heroin more potent than morphine?

It is acetylated, can cross BBB easier

what are the 2 types of transport proteins

SLC and ABC (ATP binding cassette)

Why does cyclosporin have a low bioavailability?

presence of ABC transporters

describe the structure of PGPs ( P-glycoproteins)

2 repeating units, 2 drug binding sites

accumaltion of amyloid B in the brain can cause what?

Alzheimer's

What does LRP-1 do?

removes toxins (e.g. amyloid b) from brain

what forms the Blood-CFS Barrier?

choroid plexus and arachnoid membrane

What is ISF & where is it found?

interstitial fluid surrounding the brain