Determining Blood-Brain Barrier Disruption Using Fluorescent Dyes in an EAE Mouse Model

Start with a solution containing green fluorescent dye bound to a large dextran chain. Then, add a solution of red dye bound to a small dextran chain.

Mix the dyes thoroughly and take into a syringe.

Inject this dye mixture intravenously into an anesthetized mouse through the retro-orbital sinus, a vein behind the eye.

This mouse suffers from experimental autoimmune encephalomyelitis or EAE.

In this condition, the blood-brain barrier is disturbed with weakened tight junctions between the endothelial cells of the brain's blood vessels with gaps.

Allow the mouse to fully awake and regain motility, enabling the dyes to circulate.

The red dye with the small dextran chain easily diffuses through the small gaps into the brain tissue, while the green dye bound to the large dextran chain diffuses if the damage is severe.

The amount of each fluorescent dye in the brain tissue correlates with the extent of the blood-brain barrier disruption.