Calcium ion signaling in astrocytes

Abstract

Ca 2+ signaling has been recognized as one of the major second messenger steps in most cell types, including astrocytes, the major macroglial cell type in vertebrate nervous systems. Astrocytes are by no means a homogeneous group of glial cells, but comprise a number of different cell types (see Chap. 1). However, in contrast to a decade ago, when mammalian astrocytes were divided into either protoplasmic type 1 or fibrous type II astrocytes, we assume today that there are many types of astrocytes in different brain regions. Another classification has recognized astrocytes with a dense distribution of glutamate uptake transporters (EAAT, excitatory amino acid transporter) and poor equipment of ionotropic glutamate receptors, while another type of astrocytes shows a poor expression of EAATs, but prominent distribution of ionotropic glutamate receptors. As with all of these cell type