Hippocampal neurons (IMAGE) Vlaams Instituut voor Biotechnologie Caption Hippocampal neurons with staining for endosomes (turquoise and purple) and lysosomes (yellow). When the PSEN2 gene is absent or carries a familial Alzheimer-related mutation (middle), the lysosomes become noticeably enlarged. Credit VIB Usage Restrictions No restriction License Original 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.