BSCB Newsletter, Winter 2001

Book Reviews

Endocrine Cell Culture
Successful Scientific Writing
Neuronal Growth Cones
More books for review

Neuronal Growth Cones: The Molecular Approach to Their Behaviour
Phillip R. Gordon-Weeks
£55
Hardback, 271 pages. Cambridge University Press; ISBN: 0521444918

We are able to write this review and you are able to read it because the 15 billion or so neurons in each of our brains have connected to each other in a stereotypical pattern of staggering complexity. Each individual connection has been made during our development by the movement of cellular elements called growth cones from one cell to another. The navigational feats achieved by growth cones are often spectacular, requiring them to make numerous accurate turns over distances that are enormous when compared to their own size.

Ramon y Cajal discovered and named growth cones in the late 19th century, using the analogy of a 'living battering ram, soft and flexible' to describe them. Phillip Gordon-Weeks uses other analogies, 'a spider spinning a web or the laying of a telephone cable by a cable-laying ship', and describes the appearance of a growth cone as an enlargement at the end of a growing neurite with 'fine, finger-like extensions'. These newer analogies are satisfying, given that we now know that growth cones possess remarkable autonomy from their cell bodies, retaining the ability to move and navigate even when their connection to the rest of the cell is severed.

This book provides a detailed treatment of our current knowledge of the neuronal growth cone and is intended for graduate students and more experienced researchers. It comprises a general introduction, a description of the growth cone cytoskeleton, axon pathfinding, intracellular signalling in growth cones, and a brief chapter on synaptogenesis. The book is primarily a compendium of 100 years of experiments investigating growth cone function, from their discovery, through analysis of their mechanical properties to the identification and characterisation of some of the molecules involved. The text is enthusiastically written and extensively referenced.

The field of growth cone navigation is expanding very rapidly and a book such as this, which draws together and summarises the current state of knowledge, is certain to be of value to those researching this topic. As Phillip Gordon-Weeks admits in the preface, the exponential increase in publications on the growth cone as he wrote the book subjected him to a 'Herculean task', and inevitably the downside of this being such an active topic of research is that aspects of the book will become dated quite rapidly. For example, the GTPases (Rho, Rac and Cdc42) that regulate changes in the cytoskeleton in response to growth cone guidance cues are only given one page, the semaphorins are referred to by their old names rather than the nomenclature adopted in 1999, and the Robo/Slit axon guidance system is described very briefly. Yet the success of the book in consolidating such a large body of literature, describing current understanding that is unlikely to alter much, far outweighs problems of omitting the latest findings. In fact, his approach gives the narrative a more rounded feel and does not confuse the reader with a mass of up-to-the-minute data that has yet to fit into a clear picture. We are sure that many of those in or entering the field will consult the book for many years to come.

One aspect of the book is disappointing: the figures. Even for the experienced reader, more figures would make for a more relaxing read. Where figures are present, they are often of primary data. Certainly, there are some striking pictures of growth cones that illustrate points made in the text, but we yearned for more summary diagrams to emphasise and summarise key points and to interrupt and provide a focal point for the often long tracts of text. Where diagrams are used, they are sometimes drawn with poor quality. Unfortunately, those who consult the book to find clear illustrations of sufficient quality for teaching will be largely unsuccessful.

In summary, this book provides a rich source of information on the experimental attack on the neuronal growth cone. It contains a comprehensive record of how people have thought about growth cones over the past 100 years, the experiments they have done to look at their behaviour, and a sprinkling of experimental anecdotes and original data. Each chapter, and sections within chapters, can be read in isolation making it a useful reference text. We would recommend it to anyone who, like us, is working on axonal growth and guidance and wishes to consult a single reference to deepen their understanding of what goes on in these tiny structures, whose 'sources of marvellous power by which nerve expansions make direct contact with far-off ' cells' first fascinated Ramon y Cajal 100 years ago.

Tom Pratt and David J. Price, University of Edinburgh