Clostridium botulinum is a bacterium that produces the botulinum toxin. when locally applied, to parts of the face for example, neuromuscular transmission is blocked, and muscles that cause wrinkles cannot contract (no more wrinkles). how exactly does the toxin block nueromuscular transmissions? clostridium botulinum is a bacterium that produces the botulinum toxin. when locally applied, to parts of the face for example, neuromuscular transmission is blocked, and muscles that cause wrinkles cannot contract (no more wrinkles). how exactly does the toxin block nueromuscular transmissions? botulinum toxin stabilizes the link between synaptic vesicles and the axon terminal membrane. botulinum toxin cleaves the tethering proteins, inhibiting accumulation at the membrane. botulinum toxin cleaves the acetylcholine receptor. botulinum toxin cleaves snap-25, blocking fusion of the vesicle.