The breakdown of responsibilities and mechanisms of the heavy (HC) and light chain (LC) of tetanus neurotoxin: The HC assists in binding of TeNT to both the ganglioside receptor and the final receptor. Once TeNT is in the vesicle in the inhibitory interneuron space the HC is also involved in translocation of the LC into the cytoplasm. Then the LC, characterized by zinc endopeptidase activity, inhibits neurotransmission by cleavage of synaptobrevin 1.