solve the CHAPTER MYSTERY

POISONING ON THE HIGH SEAS

Because of a sketch done by the ship's naturalist, Georg Forster, it is suspected that Cook and his men most likely ate Tetraodon lagocephalus sceleratus, also known as the Silverstripe blaasop. Bacteria that live in the fish's liver, gonads, intestines, and skin produce a poison called tetrodotoxin. The poison can remain active even after the fish is cooked at high temperatures. Tetrodotoxin binds to and blocks voltage-gated sodium channels, especially in the peripheral nervous system.

Unlike the men on Cook's ship, today, some Japanese chefs are specially trained to prepare fish—known as pufferfish—that contain this toxin. The dish, known as fugu, is highly prized by diners in exclusive restaurants. The prepared fish have a unique taste and produce a tingling sensation in the mouth and throat when eaten. Improper preparation of fugu can lead to serious consequences for the diner, including death.

Obviously, tetrodotoxin doesn't poison the fish that produce it. Studies of the fish's genome have revealed a mutation in the gene that codes for the structure of sodium channel proteins. The mutation changes the surface shape of the channel, and prevents the toxin from binding to it.

1. Infer Based on the location of bacteria in Tetraodon, what methods are likely involved in preparing fugu?

2. Apply Concepts Describe in your own words why the fish are not affected by their own toxin.

3. Connect to the Some researchers have explored the possibility of using tetrodotoxin to treat severe pain. Why might the toxin be useful in this way? What safety concerns would you have to consider when designing a study to test this possibility?