Synaptic transmission is a multi-stage process each with its own kinetics

After the terminal is depolarized, vesicles have to be recycled and filled with transmitter

After the terminal is depolarized, microtubules have to release filled vesicles to docking proteins

Vesicles take time to move to the active zone when the terminal is depolarized

Vesicles take time to be filled when the terminal is depolarized