Astrocytes were first described in 1858 by Rudolf Virchow, and in the second half of the 19th century, a number of distinct astrocyte types were identified. With the exception of the radial astrocytes in neurogenic regions of the brain (see above), reactive astrocytes in response to injury, and types defined solely by morphology (such as velate astrocytes of the cerebellum and olfactory bulb), the modern understanding of astrocyte diversity essentially stands as it stood in 1900: the major types of mature astrocytes are believed to be the Müller glia of the retina, the Bergmann glia of the cerebellum, and the widely distributed protoplasmic and fibrous astrocytes (Ben Haim and Rowitch, 2017).
