Mode of Action of the Tetanus Exotoxin

Tetanus exotoxin is a neurotoxin that binds to inhibitory interneurons of the spinal cord and blocks their release of inhibitors. It is these inhibitors from the inhibitory interneurons that eventually allow contracted muscles to relax by stopping excitatory neurons from releasing the acetylcholine that is responsible for muscle contraction. The toxin, by blocking the release of inhibitors, keeps the involved muscles in a state of contraction and leads to spastic paralysis, a condition where opposing flexor and extensor muscles simultaneously contract.

© 2000 Gary E. Kaiser
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Updated: Jan. 13, 2000
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