Botox can make your face muscles stay put, but it may not stay put in your face. Evidence from experiments with rodents suggests that the neurotoxin can cruise along nerve cells and remain active beyond the injection site.
Understanding the mechanisms and pathways that toxins use is "of fundamental importance," comments Giampietro Schiavo, of Cancer Research UK in London, who studies a related toxin that causes tetanus and also travels in the body via nerve cells.
Botox is actually a trade name for one of several toxins that target nerve cells and are made by the rod-shaped bacterium Clostridium botulinum. While extremely poisonous in the wrong dose—the neurotoxi