Multivesicular release (MVR) is the phenomenon by which individual chemical synapses, forming the junction between neurons, is mediated by multiple releasable vesicles of neurotransmitter. In neuroscience, it is a subject of debate whether one or many vesicles are released per action potential.
Examples
In the mammalian brain, MVR has been shown to be common in CA1 pyramidal cells and Schaffer collateral cells. It has also been proposed and then refuted at the ribbon synapses formed between inner hair cell and spiral ganglion neurons. Recent evidence points to a possibility of MVR at neocortical connections of the somatosensory cortex.
References
Multivesicular release Wikipedia(Text) CC BY-SA