“…In contrast to non-CNS barriers that constitutively express high levels of both adhesion molecules VCAM-1 and ICAM-1 (Steffen, Breier, Butecher, Schultz, & Engelhardt, 1996;Hofman et al, 2002), we and others have shown that brain-derived endothelial cells (Brown, McFarlin, & Raine, 1991;Jovanova-Nesic, & Shoenfeld, 2006) have reduced levels of expression of these molecules under basal conditions (Wolburg, Gerhardt, Schulz, Wolburg, & Engelhardt, 2004), and represent a less permissive barrier to cell migration comparing to that high endothelial venules (HUVECs) in the periphery (Wong, Prameya, & Dorovini-Zis, 1999).…”