Blood Vessel in The Brain (IMAGE) Cell Press Caption The image depicts a cross-sectional view of a brain's blood vessel with cell nuclei shown in blue. Some endothelial cells at the inside vessel wall are activated by type-I interferons (purple) following a viral infection. Yellow cells within the vessel's lumen represent erythrocytes. Credit Thomas Blank Usage Restrictions Credit Required. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.