Binds to Na+ channels, ☆inhibiting Na+ influx and preventing action potential conduction
・Tetrodotoxin (puffer fish)
・Saxitoxin (dinoflagellates in "red tide")
Binds to the Na+ channel, keeping it open and causing persistent depolarization
・Ciguatoxin (exotic fish, Moray eel)
・Batrachotoxin (South American frogs)