Blood-Brain Barrier Diagram (IMAGE) Georgia Institute of Technology Caption Illustration of human astrocytes (white) interfacing with endothelial cells in the vasculature. On the right, aquaporin-4 is expressed for the exchange of water and some nutrients and waste. Credit Georgia Tech / Kim lab / Yonsei University College of Medicine Usage Restrictions None 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.