Nervegrowth (IMAGE) Duke University Caption Very small tubes filled with two kinds of growth factors show the regrowth of damaged nerve fibers (central area). On the right is a chemical signal that transforms immune system macrophages into healing cells. On the left is a more robust nerve grown with a signal that recruits undifferentiated cells and makes them specialize as pro-healing macrophages. Credit Ravi Bellamkonda, Duke University 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.