Researchers have identified which areas of the human nervous system are effected by the the tropical disease, called ciguatera. Ciguatera is contracted by eating reef fish and is the world's most common form of non-bacterial food poisoning, affecting 50,000-500,000 people each year.
Some reef fish contain ciguatoxins which are responsible for the disease. The first recorded incident of ciguatera was in 1774, when British sailors led by Captain James Cook were exploring the coast of Vanuatu and experienced a peculiar type of poisoning after eating fish.
The most prominent symptom of ciguatera is cold allodynia, a disorder where exposure to cool objects or water causes severe burning pain and electric shock-like sensations. In addition to the burning pain associated with cool temperatures, ciguatera also causes nausea, diarrhea, intense itchiness, and abdominal pain.
Professor Richard Lewis and Irina Vetter, scientists with the University of Queensland's Institute for Molecular Bioscience, led the research team that examined the effect of ciguatoxins on the body's nervous system. In a detailed study of nerve channels, the team found that ciguatoxins don't directly affect the channels responsible for sensing pain and cold. "We identified the channels in the nervous system that the ciguatoxins act on, which in turn activate the nerves that sense cold and pain," Vetter says.
"It's the first time anyone has established the molecular and cellular basis of ciguatoxin-induced cold pain and may lead to a treatment for this symptom."