Tetrodotoxin is a potent toxin found in a variety of organisms including the pufferfish. The toxin binds to the extracellular side of the Na+ channel and prevents channel opening. This leads to paralysis of muscles, including the diaphragm. Death from respiratory failure can occur after ingestion of as little as 1 mg of the toxin. Why does this toxin cause paralysis? Question 7 options: The axon membranes become over-depolarized. The Na+ channels remain in the inactive, refractory state. The Na+ channel does not open wide enough to allow enough Na+ through the channel. The membrane depolarization is not amplified along the axon.