TRP channel blamed for burning cold after a tropical fish meal.

Ciguatera is one of the most common forms of food poisoning, occurring after consumption of fish contaminated with ciguatoxins. New work by Vetter et al (2012) reveals the key molecular players that underlie the altered temperature sensation associated with ciguatera. In particular, they show that ciguatoxins act on sensory neurons that express TRPA1, an ion channel implicated in the detection of noxious cold. Imaging yourself in the following idyllic settings: a white sandy tropical beach, blue sea and sky; and a barbecue on which your catch of the day, a 4-kg red snapper, is being grilled for dinner. But then, just a few hours after savouring the delicious fish meal, you undergo another unforgettable but far less heavenly experience: it starts with severe nausea, vomiting and diarrhoea, followed by disturbing neurological symptoms including headache, numbness and burning of the skin. You contracted ciguatera, a food-borne disease that affects an estimated 500 000 persons each year, particularly in the tropical and sub-tropical coastal regions (Dickey and Plakas, 2010). So what causes ciguatera? The prime culprits are dinoflagellates of the genus Gambierdiscus, small microalgae that produce a group of fat-soluble toxins called ciguatoxins and grow on macroalgae in coral reefs (Yasumoto et al, 1977). Gambierdiscus-containing macroalgae serve as food for herbivorous fish, which results in the introduction of ciguatoxins into the food web. These smaller, herbivorous fish are on the menu of large, carnivorous reef fish, such as mackerel, red snapper, or barracuda, which can accumulate ciguatoxins in the fatty parts of their body over years, apparently without any distress or obvious sign of disease. However, when such a mouth-watering but toxin-loaded catch appears on your menu, just a few bites (or sips of fish broth) can be sufficient to induce ciguatera (Figure 1A). Disturbingly, affected fish looks, smells, and tastes normal, and ciguatoxins are resistant to grilling, drying, or cooking of the fish, so there is no straightforward method to predict whether your tropical culinary dream will be followed by a