Brain Guardians Remove Dying Neurons (IMAGE) Salk Institute Caption Salk scientists show that two immune cell receptors, called Mer and Axl, are responsible for consuming dead or dysfunctional brain cells. An accumulation of dead cells (green spots) is seen in the subventricular zone (SVZ) -- a neurogenic region -- of the brain in a mouse lacking the receptors Mer and Axl. (Blue staining marks all cells.) No green spots are seen in the SVZ from a normal mouse. Credit Salk Institute Usage Restrictions with credit and related coverage 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.