Abstract
This chapter outlines the experimental paradigms for the study of plasticity at the neuromuscular junction (NMJ) and discusses the cellular parameters are to be altered by plasticity at the NMJ. A number of the known molecules that can effect plastic changes at the NMJ by the activation of signal transduction pathways and the way they initiate these processes are discussed. The chapter also discusses the internal machinery of signal transduction and the way a cell reacts when plasticity-inducing pathways are activated. Functional plasticity refers to changes in the magnitude of synaptic transmission that occur without gross structural change, usually on a short timescale. The Drosophila NMJ is a glutamatergic synapse. Release of glutamate into the synaptic cleft activates ionotropic glutamate receptors (iGluRs) permeable to cations. The resulting glutamate-induced depolarization of the muscle membrane leads to the opening of a variety of voltage-dependent channels. The Drosophila NMJ has proved to be a fertile ground for the study of plasticity and signal transduction. Molecules that are involved in invertebrate and vertebrate behavior inevitably have a role in the development or modulation of this experimentally accessible synapse.