Table 2.

Heterogeneity of the BBB in different segments of the brain microvasculature.

	arterioles	capillaries	venules
gene expression		increased expression of genes of the solute transport system	higher expression of inflammation-associated genes
TJs			looser arrangement of junctional strands than in capillaries, EAE: loss of claudin-5
transporters	lower P-gp levels	high and uniform P-gp levels	high and uniform P-gp levels
astrocytic endfeet	thickest astrocytic perivascular sheaths	GFAP-negative astrocytic processes, highest density of contacting processes, thinest astrocytic perivascular sheaths