Astrocyte nerve cell. Fluorescent light microscope of an astrocyte cell from a human brain. Glial-fibrillary acidic protein, a type of intermediate filament (IF), part of the cell's cytoskeleton, has been dyed green. Cell nuclei, which contain the cell's genetic information, have been dyed blue. The nuclei of fibroblast cells are seen in the background. Astrocytes are a type of glial cell. They provide structural support and protection for neurons (nerves cells) and also supply them with nutrients and oxygen. The cells cannot transmit electric signals and so insulate neurons from one another.