Talk about the types of astrocytes

Two types of astrocytes are described: - Fibrous astrocytes, especially present in the white matter and having many fibrils and fine extensions. By controlling the immediate ionic environment of neurons, these astrocytes participate with endothelial cells, to the formation of the blood-brain barrier. - Protoplasmic astrocytes mainly present in the gray matter. They have few fibrils but thick extensions. They surround neurons and the synaptic cleft and capture back neurotransmitters. Their nucleus is round and light colored. Their cytoplasm contains glycogen granules.