There is a toxin extracted from pufferfish called tetrodotoxin (TTX), which completely inhibits (blocks) voltage-gated sodium channels. In low doses it can cause a slight numbness (people eat...

Extracted text: There is a toxin extracted from pufferfish called tetrodotoxin (TTX), which completely inhibits (blocks) voltage-gated sodium channels. In low doses it can cause a slight numbness (people eat contaminated pufferfish sometimes!), in high doses it is lethal. Why is this the case? It prevents glutamate uptake and reuptake, causing seizures in the brain Ob. It causes excess neuronal activity, leading to excitotoxicity and cell death It destroys myelin around axons, slowing action potential propagation It prevents action potentials from being initiated, stopping all synaptic transmission O 0 o o