Many transmitters, few sparks

With the increasing prominence of disorders of the brain, drug abuse and sophisticated pharmaceutical therapies, it is hardly surprising that an increasing number of new textbooks focus on the chemical systems of signalling between brain cells: neuropsychopharmacology. In this book, the jaw-breaking term covers the operations of the many different transmitter systems in the brain, both at the level of communication between the cells themselves, as well as from the perspective of the behavioural sequelae.

The authors version of events has been inspired by the twin advances of brain imaging and molecular biology. At first glance, however, the pages do not appear to be particularly student friendly. Nowadays one is becoming used to slick pedagogic devices - bullet-point summaries, self-test checks, titles in the form of bottom-line statements - to help the biomedical student plough through very different subjects on information-dense courses. No such concession here, however, to the hard-pressed reader. Nor will the figures necessarily gladden the eye. Particularly unaesthetic cases in point are the figures showing the distribution of the different transmitter systems in the brain. No attempt has been made to present these key illustrations in a uniform style. Instead each retains the original look of its respective source.

However, the scope of the book is timely and admirably ambitious. The contents are divided into four broad areas: basic concepts, neurotransmitter concepts, major drug classes and clinical applications. But the ordering within the initial section sets a rather dry tone. In my own experience early mention, as here, of "methods" and "techniques" is the kiss of death to student interest. The technical terms and procedures would have been more happily housed as an appendix or included in the chapters discussing neurons, synaptic transmission or a particular chemical system. Boxing the more obscure data would have made it easier to absorb.

Generally, the material is appropriate for its target student readership. A personal gripe was to see pharmacology defined in the time-honoured way as "the study of actions of drugs..." which, to my mind, carries too much of the taste of the pharmacy instead of conveying the fascination of the pharmacologist in the underlying systems on which the external substance can act. Pharmacology is more accurately the "study of chemically sensitive sites" in the body.

Indeed, much of the book is not about drugs at all. The remainder of the basic concepts section deals with the predictable topics of neurons and their supporting cells, glia, functional neuroanatomy, neurophysiological mechanisms and synapse structure and function. Each of these issues could have merited a book in its own right, and it is a strength of this work that such inter-related yet disparate topics are housed under one roof. On the other hand, there is little attempt at a unifying framework. Although the reader will welcome clear discussion on subjects such as immediate early genes, they might be dismayed at the rather flat description, region by region, of different parts of the brain. They might also be misled into the easy and erroneous stance that brain regions have clear-cut functions. Brain structures have very different functions and we still do not know how most of them contribute to the coordination of an integrated behaviour such as thought or emotion.

The rather limited premises that characterise the organisation of material, can also be seen in the presentation of the "concepts" themselves. For example, the parallels in distribution between the diffuse amines and acetylcholine systems are ignored: hence valuable clues are missed as to the action of these substances in the brain. For some reason histamine is even tacked onto the back of a chapter on a completely different system, amino acids, instead of being described in line with its amine cousins, with whom it shares much in terms of distribution and relation to arousal levels. The student will learn about each system well enough, but it will be a piecemeal acquisition of facts.

Another problem is that the worn mindset of "inhibition and excitation" is never far away - a yes/no idea of signalling that has shackled neuroscience to computer technology for years. Following this binary mode of thought, drugs are divided accordingly into stimulants and depressants. The result is not surprisingly that a large number of drugs which cannot be so simplistically reduced, end up in a rather awkward pot-pourri chapter entitled vaguely "Mind-Altering Drugs".

In short this book contains no surprises no new way of looking at a complex, multidisciplinary subject: hence a great chance has slipped through the authors' fingers. On the other hand, the compartmentalised organisation of the material and the fact that a broad sweep of facts is covered, would ensure that specific topics could be reliably accessed. Principles of Neuropsychopharmacology is a sound, up-to-date reference book, but not an inspirational read.

Susan Greenfield is professor of pharmacology, University of Oxford.