Short-term Facilitation and Depression of Transmitter Release at Amphibian Sympathetic Ganglionic Cells - Mathematical/Computa- tional Modeling.

There have been few investigations of the short-term plasticity of synaptic transmission at amphibian sympathetic ganglionic cells where the frequency of miniature excitatory postsynaptic potentials is too low to measure an accurate quantum size. This has made it difficult to investigate the mechanism of synaptic transmission at the ganglionic cells by quantal analysis. A theoretical equation, therefore, is proposed. This equation is based on the premise that transmitter release is due to the product of two factors: intracellular calcium ([Ca2+]i) and acetylcholine (ACh), which is a readily releasable transmitter. The equation accounts for the mechanism of synaptic facilitation and depression of transmitter release at the ganglionic cells in the paired-pulse experiments.