Refilling

The Vesicles are reloaded with neurotransmitter in the nerve terminals. The vesicles are then acidified by the action of the proton ATPase. The transport of transmitter into the vesicles is then driven by the secondary active transport with H⁺ efflux given that the energy as shown in figure.

                                                                  Figure: Vesicle refilling

The Nerve terminals are incapable of protein synthesis. The Peptide transmitters are synthesized in the cell body, secreted into the lumen of the rough endoplasmic reticulum (RER), and enclosed for export by the Golgi apparatus, by which the loaded vesicles are budded. Then these are moved to the terminal by rapid axoplasmic transport.