The studies by Santiago Ram6n y Cajal on astrocytes, and the extense work developed by Pio del Rio Hortega dealing with microglia and oligodendrocytes are with no doubt two important milestones of neurobiology, and specially cf glial research. Since these classical studies, the curiosity for understanding glial cells has continuously grown. During the last two decades, the development of new meth ods of study, including cell culture techniques and the use of histochemical and immunocytochemical markers, has allowed a remarkable advance in this field. This increasing interest is reflected by...

The studies by Santiago Ram6n y Cajal on astrocytes, and the extense work developed by Pio del Rio Hortega dealing with microglia and oligodendrocytes are with no doubt two important milestones of neurobiology, and specially cf glial research. Since these classical studies, the curiosity for understanding glial cells has continuously grown. During the last two decades, the development of new meth- ods of study, including cell culture techniques and the use of histochemical and immunocytochemical markers, has allowed a remarkable advance in this field. This increasing interest is reflected by...