Botulinum neurotoxin has achieved celebrity status through its use in cosmetic treatment. The most lethal toxin known in nature, it is also a notorious cause of the deadly food poisoning, botulism. Lay patients are less aware, however, that its ability to relax and paralyse muscles has many therapeutic applications.
It is not a perfect therapy, despite being used to treat inappropriate or excessive contractions of muscles throughout the body. Botulinum neurotoxin remains a highly toxic substance and a recognised bioterrorism threat, and it is only safe when used in low nanogram quantities. Since the toxin evolved to target nerve cells specifically, its effects are limited to conditions involving peripheral nerve transmission, and muscle relaxation in particular.
Both the toxic and therapeutic effects of botulinum neurotoxin arise from the same property: the ability to inhibit neurotransmitter release from nerve cells. Imagine if botulinum neurotoxin’s ability to target and inhibit nerve cell secretions could be widened to other cell types, while rendering it non-lethal. |