A glia-centric perspective

Glial Cell Development: Basic Principles and Clinical Relevance (2nd edn)edited by Kristjan R. Jessen and William D. Richardson, Oxford University Press, 2001. £79.50 (480 pages) ISBN 0 198 52478 1A senior scientist came to visit our program, looked at my desk, noticed this book and said ‘A book on glial cell development? Why would anyone need that?’ The answer is, of course, evident in the question. Even with the advances in glial biology that have occurred in the past decade, there is still a general perception that glial cells are simply the buttresses of a neuron-centric nervous system. The essays in Glial Cell Development provide a clear insight into why this notion is outmoded.The book contains 21 chapters written by leaders in the field, and addresses issues at the forefront of glial biology. Somewhat surprisingly, there is no foreword from the editors to orient the reader as to the overall goal of the volume. This would have been helpful, as the main title on the front cover mentions only glial development. Although several of the chapters do deal directly with this topic, more than one third of the book is devoted to the role of glial cells in a variety of nervous system pathologies – as highlighted by the subtitle of Basic Principles and Clinical Relevance. The majority of chapters provide comprehensive updates of the field, significant synthesis and frequently novel perspectives on the relevant issues.In the first edition of this book, the clinical aspects of glial biology were possibly of more general interest than the basic principles of glial development. Today, with our understanding of the molecular mechanisms mediating cell-fate selection among products of the neuroepithelium, this is no longer so evident. The dramatic role of transcription factors in neural cell determination has projected glial-cell biology to the very forefront of developmental neuroscience. These aspects are well covered in several chapters on Schwann cell development and early oligodendrocyte induction and maturation. By contrast, the molecular control of astrocyte specification is, as a field, clearly less well developed. Inclusion of a review of current understanding of microglial development and function provides completeness in glial coverage.Somewhat surprisingly, relatively few chapters deal with the biology of myelination. A comprehensive overview of the myelin-specific genes provides insights into the molecular control of myelin-sheath formation; the structure of the node of Ranvier is discussed in detail, as befits this crucial specialization. The clinical aspects of glial biology are well covered, with chapters on injury and regeneration responses, as well as on the role of myelin and oligodendrocytes in inhibition of axon outgrowth. As expected in a book on glia, both hereditary demyelinating neuropathies and multiple sclerosis are presented.A delightful consideration of the evolutionary concepts of myelin biology bring together molecular and paleomyelinological approaches in a refreshing and novel discussion. Likewise, the chapters on glial tumors of the CNS and PNS are a welcome addition, as they present important aspects of glial cell biology that are often excluded from such discussions.One disappointment with the volume is the relative paucity of discussion of stem cell biology. A single chapter discusses stem cells from a rather restricted perspective, following a consideration of myelin repair by transplantation. Given the burgeoning interest in neural stem cells, and the emerging notion that certain glia (astrocytes and oligodendrocyte precursors) might have the capacity to de-differentiate into multipotent cells, this subject was surely worthy of additional discussion both from developmental and therapeutic perspectives. Perhaps we can look forward to a complete coverage of this topic in the third edition.Overall, the volume is well produced. The chapters are informative and provide access to the key references in the area. The illustrations are clear and useful, although it is rather disappointing that, in this age of color publishing, most of the illustrations are in black and white. The volume will be helpful to those entering the field of glial biology and for use as a teaching resource. The visiting senior scientist, a leader in the field of glial biology, might not need this book – but for the rest of us, the contents provide considerable momentum for the swing of the pendulum from a neuron-centric to glia-centric view of the nervous system.