abstractexocytic post - fusion events play an important role determining the composition and quantity of cellular secretion . 
 in particular , ca2 + -dependent regulation of fusion pore dilation / closure is a key regulator for fine - tuning vesicle content secretion . 
 this requires a tight temporal and spatial integration of vesicle fusion with the pm , ca2 + signals and translation of the ca2 + signal into fusion pore dilation via auxiliary factors . 
 yet , it is still mostly elusive how this is achieved in slow and non - excitable secretory cells , where initial ca2 + signals triggering fusions will abate before onset of the post - fusion phase . 
 new results suggest , that the vesicles themselves provide the necessary itinerary to sense and link vesicle fusion to generation of local ca2 + signals and fusion pore expansion .