Elementary components of synaptic transmission.

The analysis of chemical transmission at synapses, in particular at the neuromuscular junction, has proceeded from the cellular to the molecular level. Gradual refinements in electric recording technique have brought to light new features, first the quantal delivery of the transmitter substance, in multimolecular packets, from the nerve endings, and more recently the statistical elements of the postsynaptic potential change which arise from the molecular bombardment by acetylcholine and the transient opening of individual ion channels in the end-plate membrane.