Undernormal circumstances, the acetylcholine-containing vesicles are located in the nerve endings. They bind to the cell membranes through SNARE protein complexes N-ethylmaleimide-sensitive factor attachment protein receptor, which include VAMP vesicle-associated membrane protein where type B exercises its main action, and SNAP-25 synaptosome-associated protein of 25 kDa where type A has its action. They then release their content into the synaptic cleft through exocytosis.
En circunstancias normales, en las terminales nerviosas motoras se encuentran las vesículas que contienen acetilcolina, y estas se unen a la membrana celular por medio de complejos proteínicos N-ethylmaleimide-sensitive factor attachment protein receptor SNARE que incluyen la vesicle-associated membrane protein VAMP, donde actúa principalmente la tipo B, y la synaptosome-associated protein of 25 kDa SNAP-25, donde actúa la tipo A; luego liberan su contenido a la hendidura sináptica por medio de exocitosis.