Table 1.

Detection of tight junction proteins by immunofluorescence staining of the healthy brain

	Parenchymal blood vessel endothelium	Meningeal blood vessel endothelium	Choroid plexus endothelium	Choroid plexus epithelium	Ependymal cells
Claudin-1	–	+a	–	+	+
Claudin-2	–	–	–	+	+
Claudin-3	+	+	–	+	±
Claudin-5	+	+	+	–	–
Occludin	+	+	–	+	+
ZO-1	+	+	+	+	+
ZO-2	+	+	+	+	+

^aDiffuse rather than junctional staining