A system to study mechanisms of neuromuscular junction development and maintenance

Abstract

The neuromuscular junction (NMJ), a cellular synapse between a motor neuron and a skeletal muscle fiber, enables the translation of chemical cues into physical activity. The development of this special structure has been subject to numerous investigations, but its complexity renders in vivo studies particularly difficult to perform. In vitro modelling of the neuromuscular junction represents a powerful implement to fully delineate the fine tuning of events that lead to subcellular specialization at the pre-synaptic and post-synaptic sites. Here we describe a novel heterologous co-culture in vitro method using rat spinal cord explants with dorsal root ganglion and murine primary myoblasts to study neuromuscular junctions. This system allows the formation and long-term survival of highly differentiated myofibers, motor neurons, supporting glial cells and functional neuromuscular junctions with post-synaptic specialization. Therefore, fundamental aspects of NMJ formation and maintenance can be studied using the described system which can be adapted to model multiple NMJ-associated disorders.