Stem Cells (IMAGE) Neural Regeneration Research Caption After 3 days of culture, differentiated neural stem cells within the proliferative neurosphere were strongly positive for nestin. The arrow indicates a nestin-positive neurosphere. Credit <i>Neural Regeneration Research</i> 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.