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 creation of local and international glial networks, the publication of the journal Glia, the celebration of periodic interna- tional meetings and the publication of extensive books focused on glial cells. In February 1997, with the establishment of the Spanish Glial Network, arose the early idea of publishing a compendium of selected work by Spanish glial research teams, which has fmally materialised in Understanding Glial Cel/s, a book whose objective is to present topics of current interest in glial cell biology.

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 creation of local and international glial networks, the publication of the journal Glia, the celebration of periodic interna- tional meetings and the publication of extensive books focused on glial cells. In February 1997, with the establishment of the Spanish Glial Network, arose the early idea of publishing a compendium of selected work by Spanish glial research teams, which has fmally materialised in Understanding Glial Cel/s, a book whose objective is to present topics of current interest in glial cell biology.