Glutamatergic synthesis, recycling, and receptor pharmacology at Drosophila and crustacean neuromuscular junctions

Invertebrate glutamatergic synapses have been at the forefront of major discoveries into the mechanisms of neurotransmission. In this chapter we recount many of the neurophysiological advances that have been made using invertebrate model organisms, from receptor pharmacology to synaptic plasticity and glutamate recycling. We then direct your attention to the crayfish and fruit fly larva neuromuscular junctions, glutamatergic synapses that have been extraordinarily insightful, the crayfish because of its experimental tractability and Drosophila because of its extensive genetic and molecular resources. Detailed protocols with schematics and representative images are provided for both preparations, along with references to more advanced techniques that have been developed in these systems. The chapter concludes with a discussion of unresolved questions and future directions for which invertebrate neuromuscular junction preparations would be particularly well suited.