Differentiation of neuromuscular junctions in cultures of embryonic Drosophila cells.

Cultures were prepared of embryonic cells from Drosophila melanogaster. Neurons and myocytes differentiated in vitro from their respective stem cells. Electron microscopy showed that neuromuscular junctions formed where axons contacted myocytes. Electrical stimuli were applied to axons and these caused contractions of innervated myocytes. This is the first report of insect or other invertebrate neuromuscular junctions differentiating in vitro. In addition, this is the first system reported in which the neurons, myocytes, and junctions are completely differentiated in vitro from neuroblasts and myoblasts.