Portrait of a Killer (IMAGE) University of Montreal Caption Glial cells normally protect neurons in the retina. Credit Frédéric Lebrun-Julien, Université de Montréal 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.