SYNAPTIC VESICLE ENDOCYTOSIS MEDIATES THE ENTRY OF TETANUS NEUROTOXININTO HIPPOCAMPAL-NEURONS

Tetanus neurotoxin causes the spastic paralysis of tetanus by blocking neurotransmitter release at inhibitory synapses of the spinal cord, T his is due to the penetration of the toxin inside the neuronal cytosol where it cleaves specifically VAMP/synaptobrevin, an essential compon ent of the neuroexocytosis apparatus. Here rye show that tetanus neuro toxin is internalized inside the lumen of small synaptic vesicles foll owing the process of vesicle reuptake, Vesicle acidification is essent ial for the toxin translocation in the cytosol, which results in the p roteolytic cleavage of VAMP synaptobrevin and block of exocytosis.