Methods in Insect Sensory Neuroscience

Thomas A. Christensen, Editor
CRC Press, Boca Raton, FL
2005, 435 pp.
Price: $139.95
ISBN 0-8493-2024-0

Scriptwriters in search of amazing new attributes for aliens and superheroes will find a source of inspiration in Methods in Insect Sensory Neuroscience, edited by T. A. Christensen of the University of Arizona. Who can resist the idea of taste receptors on legs, eyes on top of the head, ultrasonic hearing, and ultraviolet vision? I myself wouldn’t mind being able to navigate in featureless suburban landscapes using the polarization pattern of the sky. There’s no doubt that Methods in Insect Sensory Neuroscience will find a Hollywood audience, but will the intended readership of working neuroscientists find the book worthwhile? I think the answer is yes. Many chapters of this well-crafted book on the major sensory systems of insects (vision, mechanosensation, audition, olfaction, and taste) can also serve a broader audience of advanced students taking courses in sensory physiology, neuroethology, and bioengineering.

The title and preface imply that Methods in Insect Sensory Neuroscience was designed as a how-to guide. I was therefore initially disappointed by the lack of a common format for the chapters. Some chapters are painstakingly detailed (for example, anyone who has ever tried to stabilize an insect’s head without dental wax will derive immediate benefit from the chapter by Galizia and Vetter). Other chapters, such as those on insect eyes (Stavenga) and olfaction (Nighorn and Zweibel), instead provide an overview of modern techniques in terms of the questions they can answer. In the chapter by Perry, Dahanukar, and Carlson, for example, we learn why RT-PCR and in situ hybridization are complementary techniques for studying expression patterns of taste receptors, but not about the special challenges of performing these techniques on small, crunchy insect tissues. But any researcher who reads the Perry et al. chapter will gain new understanding of the logic of forward and reverse genetic approaches for studying insect taste receptor genes.
Other chapters highlight the hardware and software needed to acquire and analyze electrical signals from the insect brain. The chapter by Pawlowski, Christensen, Lei, and Hildebrand on multichannel neural ensemble recording includes a consumer guide designed to help the beginner shop with confidence.

Two introductory chapters eschew methods altogether for reviews of sensory processing in the insect brain (Homberg) and insect sensory ecology (Larsson and Svensson). The Homberg chapter provides a concise overview of insect neuroanatomy, with an emphasis on function; the Larsson and Svensson chapter showcases, with infectious enthusiasm for its subject, the challenges faced by insects as they attempt to extract useful information from complex, real-world environments.

Several chapters focus on the computational properties of synaptic interactions. In a chapter on bioinspired sensors, Rind shows how understanding insect vision may lead to better eyes for robots (are you listening, Hollywood?). Her clear presentation of the Rind and Bramwell model of the lobula giant movement detector (LGMD) neuron in the locust is followed by a description of the building and testing of locust-inspired collision sensors. This exciting chapter is an outstanding example of the multidisciplinary synthesis that characterizes contemporary insect sensory neuroscience.

All of the chapters are excellent. At first reading, some seemed overly long. I soon realized, however, that the chapters that seemed long represented topics on which I already have a bit of background. In less familiar territory, I appreciated the opportunity to linger over the details of specific systems. The comprehensive chapter by Field turned out to be just what I needed to answer a student’s question about chordotonal organs on the insect head other than the Johnston’s organ. I also found—and this is no small thing for a methods handbook—that the index was genuinely useful for relocating useful tidbits. I enjoyed using entries written in plain language (e.g., Ants, brain staining) and not being forced to guess if I needed to look up AM dyes or Acetoxymethylester dyes (both are listed). I would have gone one step further and added the names of genes discussed in the text and tables to the index. I was able to find malvolio a second time on my own, but I couldn’t relocate beethoven.

Several features of this book will be very helpful to students. All of the chapters define important terms clearly, from amphinematic to mutual information rate to K-means clustering. Reference lists are extensive and provide complete citations. An appendix lists contact information, including URLs, for 34 vendors of the specialized equipment required for sensory neuroscience.

Students in search of a preparation will note that ingenious investigators are finding ways to work around the small size of Drosophila. In their chapter on taste receptors, for example, Perry et al. describe the technique of side-wall recording and its possible application to functional analyses of tarsal taste sensilla, even in tiny fruit flies.

All readers will appreciate the abundant illustrations. A color insert effectively depicts, among other topics, eye shine, the use of calcium reporters to study responses to odors in the Drosophila brain, and the advantage of color vision to butterflies.

Given the varied formats, the themes that link the chapters are conceptual, rather than practical. I therefore suspect very few readers will trek with me and the editor through the entire book, and even fewer will prop it up on the lab bench in front of them as they work. Real manuals come wire-bound and are not typically as handsome as this volume. There is still an unfilled need for a true insect sensory neuroscience techniques book, but the present volume will appeal to a broad audience and will not rapidly become dated. In the end, the surprising diversity of approaches to a common theme taken by the different chapters reflects an editor (himself a leader in the field) confident enough to let the experts define their topics and have their say. The authors and the editor are to be congratulated on having produced such an excellent book.

Susan E. Fahrbach
Department of Biology
Wake Forest University
Winston Salem,
NC, 27109
American Entomologist
Vol. 51, No.3, Fall 2005