Regulation of neuronal function by protein trafficking: a role for the endosomal pathway

Protein trafficking plays a central role in many aspects of neuronal functi on, from the release of neurotransmitters by exocytosis and the recycling o f synaptic vesicle proteins to the regulation of receptor signalling. Synap tic function can be significantly modified on a short time scale by alterat ions in the levels of receptors, ion channels and transporters both pre- an d postsynaptically. In many cases, these alterations appear to be mediated by acute changes in the rates at which the proteins are endocytosed from an d exocytosed to the cell surface from intracellular pools. While our curren t understanding of the signalling mechanisms and the intracellular pathways responsible for these acute changes is still in its infancy: intriguing de tails are beginning to emerge from a number of systems.