Table 1 Segmental heterogeneity in the brain microvasculature endothelial cells (arterioles, capillaries and venules).

Cells

 Smooth muscle cells

Yes

No

[13, 30]

 Pericytes

Yes/No

Yes

[13, 31]

 Perivascular macrophages

Yes

Yes

[13, 30]

BBB features

 Tight junctions (TJs)

Continuous and elaborate TJs/?

Highly expressed TJs

[29, 32, 33]

 Permeability for BBB markers

?

No

[30, 34]

 Astrocytic end-foot shealth

No

Yes

[29, 30]

Transporters/enzymes/receptors

 P-glycoprotein

?

+++

[35, 36]

 Na⁺/K⁺-ATPase

+++

+

[29]

 Transferrin receptor (TFRC)

–

+++

[13, 37]

 Alkaline phosphatase

+++

+++

[29]

 Mg²⁺-ATPase

+++

+

[29]

 5′-nucleotidase

+++

+

[29]

 γ-Glutamyl transpeptidase (GGTP)

?

+++

[38, 39]

 Bidirectiona/l vesicular horsedish peroxidase transport

+++

+

[29, 40]