Immunohistology of the area postrema (AP) in the healthy mouse. The V-shaped area of the AP is outlined by the MECA-32+ capillaries (top panel). ICAM-1 and VCAM-1 can not be detected on the MECA-32+ capillaries within the AP. Single CD45+ perivascular cells are present in this CVO (e.g. arrows, lower panel). Immunoperoxidase, hematoxylin counterstain. Bar = 100 μm. This result was observed 10 times.