Chapter 20 – Crustaceans as Model Systems for Teaching Neuroscience: Past, Present, and Future

<1> Abstract In addition to their role as important preparations for research, crustaceans have served as model systems for teaching basic principles of signal transmission in nervous systems, particularly in student laboratory classes. We survey published and other easily available crustacean preparations used in neuroscience teaching, focusing on neuromuscular properties, synaptic transmission, neuronal excitability, sensory physiology, heart, respiratory, and intestinal muscle control, and neurogenesis. We also briefly describe select computer simulations, behavioral exercises, and commercially available exercises that contribute to neuroscience teaching, and insect neurobiology exercises that are often complementary. Finally we suggest future directions for development of crustacean teaching exercises. <1> Introduction Crustaceans are excellent models with which to teach physiology of nervous systems and introduce students to electrophysiological techniques. These preparations come from a long history of research, mainly concentrated on decapods (crabs, lobsters, crayfish), that continues to the present (Florey 1990, Weise 2005a, 2005b; this volume). There are advantages of using invertebrates instead of vertebrates in teaching laboratories (Deyrup-Olsen and Linder 1991). (1) They often illustrate a principle more clearly than vertebrate preparations because of the relatively small number of neurons in the nervous system, many of which are identifiable across preparations. (2) They can survive and remain physiologically active at room temperature for long periods without supplemental oxygen. (3) They are generally less expensive than vertebrates. (4) They are not subject to the same governmental regulations regarding purchasing, storing, and dissecting as are vertebrates. (5) Finally, crayfish in particular are farmed commercially for fishing and food, so their removal from the environment does not damage local ecosystems. Most crustacean teaching exercises came from neurobiologists who used the preparations in their research laboratories and brought them into teaching laboratories (Parfitt 2002, Atwood 2008). For example, some versions of exercises on crustacean neuromuscular junctions (NMJs) stem from Harold Atwood's physiology class at the University of Toronto beginning in 1965 (Atwood and Parnas 1968, Baierlein et al. 2011). One of us (RRH) studied development and regeneration of the crayfish NMJ for his dissertation work and later developed this preparation for the Crawdad teaching project (Wyttenbach et al. 1999). This chapter surveys published and other easily available examples of crustacean preparations used in teaching neuroscience. We focus on teaching exercises rather than on the research that led to their development; the original research can be found in other chapters of this and related volumes (Wiese 2002a, 2002b). This overview is …