Neural Stem Cells (IMAGE) Salk Institute Caption The signaling molecule BMP keeps neural stem cells in the hippocampus, an important memory hub of the brain, in a quiescent state thus ensuring pool of neural stem cells that last a lifetime. Cell nuclei are shown in blue, nuclei of neural stem cells are shown in green, while so called radial stem cells, a subgroup of neural stem cells, are shown red. Credit Image: Courtesy of Dr. Helena Mira, Carlos III Health Institute, Madrid Usage Restrictions News media reproduction to illustrate this story permitted with proper attribution as provided above. For one time use only. 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.