The ingestion of marine animals that contain toxic substances can produce neurological symptoms. Ciguatera, tetrotoxin poisoning and paralytic shellfish poisoning are the three main syndromes of marine poisoning. Both ciguatoxins and tetrodoxins disrupt impulse transmission as they affect the activity of the Na+ channels of the axonal membrane. In ciguatera the toxin causes the Na+ channels along the axonal membrane to be hyper sensitive and open at resting potentials resulting in the spontaneous firing of the neurons. Tetrodotoxin blocks the Na+ channels resulting in disrupted action potential generation and impulse conduction leading to conduction failure. Our aim is to investigate the effects of marine neurotoxins on impulse transmission using nerve excitability testing.
