Neurosphere culture. Fluorescent light microscope of a group of neural stem cells (neurosphere) in culture. The stem cells are differentiating into neurons (red) and nerve support cells (green), which are then migrating out of the neurosphere. Cell nuclei, which contain the cells genetic information, are dyed blue. Intermediate filaments (IFs) are green and betatubulin III, one of the proteins that make up microtubules, is red. IFs and microtubules are part of the cells cytoskeleton, which is responsible for intracellular transport, cell structure and motility.