Mechanism of action of tetanospasmin is
**Core Concept**
Tetanospasmin is a neurotoxin produced by Clostridium tetani, the causative agent of tetanus. The toxin's mechanism of action is critical in understanding the pathophysiology of tetanus.
**Why the Correct Answer is Right**
Tetanospasmin acts by releasing the neurotransmitter glycine from neurons, leading to a reduction in inhibitory neurotransmission in the spinal cord. This results in an increase in excitatory neurotransmission, causing muscle rigidity and spasms. Tetanospasmin achieves this by cleaving the protein synaptobrevin, which is involved in the release of neurotransmitters from synaptic vesicles.
**Why Each Wrong Option is Incorrect**
* **Option A:** Incorrect because it does not accurately describe the mechanism of action of tetanospasmin. Tetanospasmin does not act by inhibiting the release of glycine.
* **Option B:** Incorrect because it does not accurately describe the mechanism of action of tetanospasmin. Tetanospasmin does not act by stimulating the release of glycine.
* **Option D:** Incorrect because it does not accurately describe the mechanism of action of tetanospasmin. Tetanospasmin's primary action is not through the inhibition of acetylcholine release.
**Clinical Pearl / High-Yield Fact**
Tetanus toxin's mechanism of action is a classic example of how a toxin can disrupt normal neurotransmission, leading to severe clinical consequences. Understanding this mechanism is essential for managing tetanus, which requires specific treatment, including tetanus immunoglobulin and wound care.
**Correct Answer: C. It releases glycine from neurons, leading to a reduction in inhibitory neurotransmission in the spinal cord.**