Where does vesicle collide?

In cell biology a vesicle is a small, membrane-bounded sac that buds from one compartment and fuses with another, carrying proteins and other cargo through the secretory and endocytic pathways. Palade's work on the secretory pathway, recognised in his 1975 account of intracellular protein transport, established vesicular traffic as the mechanism by which cells route newly made molecules. The referent is a dynamic transport compartment defined by its membrane and cargo, sharing only the word with a bubble void in lava.[1]

Unit

The membrane-bounded compartment and the cargo it transports between organelles

Recovery means

Not applicable

Measured by

Resolved by electron microscopy, fractionation of membrane compartments, and tracking of labelled cargo through the pathway

In neuroscience a synaptic vesicle is a specialised small vesicle in a nerve terminal that stores neurotransmitter and releases it by fusing with the presynaptic membrane when an action potential arrives, then is recycled for reuse. Südhof's 2004 synthesis of the synaptic-vesicle cycle laid out the steps of docking, priming, calcium-triggered fusion, and retrieval that make fast chemical signalling possible. The referent is a tightly regulated signalling organelle, a specialised case of the cell-biological vesicle and nothing like a cavity in cooled magma.[2]

Unit

The quantal store of neurotransmitter and its calcium-triggered release and recycling

Recovery means

Not applicable

Measured by

Studied by quantal postsynaptic responses, fluorescent markers of release and retrieval, and electron microscopy of terminals