Synapse development and maturation at the drosophila neuromuscular junction

Abstract

Synapses are the sites of neuron-to-neuron communication and form the basis of the neural circuits that underlie all animal cognition and behavior. Chemical synapses are specialized asymmetric junctions between a presynaptic neuron and a postsynaptic target that form through a series of diverse cellular and subcellular events under the control of complex signaling networks. Once established, the synapse facilitates neurotransmission by mediating the organization and fusion of synaptic vesicles and must also retain the ability to undergo plastic changes. In recent years, synaptic genes have been implicated in a wide array of neurodevelopmental disorders; the individual and societal burdens imposed by these disorders, as well as the lack of effective therapies, motivates continued work on fundamental synapse biology. The properties and functions of the nervous system are remarkably conserved across animal phyla, and many insights into the synapses of the vertebrate central nervous system have been derived from studies of invertebrate models. A prominent model synapse is the Drosophila melanogaster larval neuromuscular junction, which bears striking similarities to the glutamatergic synapses of the vertebrate brain and spine; further advantages include the simplicity and experimental versatility of the fly, as well as its century-long history as a model organism. Here, we survey findings on the major events in synaptogenesis, including target specification, morphogenesis, and the assembly and maturation of synaptic specializations, with a emphasis on work conducted at the Drosophila neuromuscular junction.

Modelling and Refining Neuronal Circuits with Guidance Cues: Involvement of Semaphorins

“…In the PNS, the neuromuscular junction (NMJ) is probably the most studied structure as example of distal cell-cell signaling and synaptic homeostasis [ 78 , 79 ]. Most of the knowledge we have to date were obtained by genetic manipulations on Drosophila melanogaster , its NMJ features being conserved in vertebrates.…”

Motor neuron boutons remodel through membrane blebbing

“…The Drosophila melanogaster larval NMJ has been widely used as an in vivo model to discover the machinery that regulates bouton formation 24,25 . Other than developmental bouton addition, which occurs throughout the larval stages, the advent of simple stimulation paradigms applied to dissected larval preparations, or intact larvae, created an opportunity to study in more detail the mechanisms required for activity-dependent bouton formation.…”

Macros to Quantify Exosome Release and Autophagy at the Neuromuscular Junction of Drosophila Melanogaster

“…A more recent example is the in vivo study of synaptic transmission using the NMJ in Zebrafish ( Brehm and Wen, 2019 ). In Drosophila , larval NMJ has been widely studied to understand not only general synaptic development ( Ruiz-Cañada and Budnik, 2006 ; Chou et al, 2020 ) and morphology ( Nijhof et al, 2016 ) but also to investigate the regulation of glutamatergic synapses ( Petersen et al, 1997 ). A unique feature of the Drosophila NMJ synapses is their big size (between 2 and 5 µm in diameter) ( Knodel et al, 2014 ), which allowed initial research without the need for super-resolution imaging techniques.…”