Neuromuscular transmission failure during postnatal development.

Neuromuscular transmission failure in rat diaphragm muscle was examined during the first two weeks of postnatal development, and was found to contribute significantly more to diaphragm fatigue induced by repetitive activation than in adult muscle. Intracellular analysis of evoked end-plate potentials indicated that neuromuscular transmission failure was due to both a block of action potential propagation and reduced synaptic efficacy.