AN ELECTRON-MICROSCOPIC STUDY OF DE NOVO FORMATION OF NEUROMUSCULAR JUNCTIONS IN TISSUE CULTURE

Trypsin dissociated somatic muscle from 11-day chick embryos was cultured upon a collagen substrate, and later confronted with 7-9 day chick lumbar spinal cord. Regions of contact between outgrowing nerve and muscle were identified light microscopically and prepared for electron microscopy. Neuromuscular junctions comparable to those found in the developing chick embryo formed de novo between homologous explants. Appearances were also found suggesting that mechanisms may exist to maintain apposition between nerve and muscle in the early stages of development of such junctions. © 1969 Springer-Verlag.