The SECRET of the ZOMBIES: the molecule that kills
In 1984, a young scientist named Wade Davis managed to obtain, with great difficulty, in Haiti the mysterious powder used by sorcerers to create zombies, the living dead from voodoo rituals well known to those who love horror films.
Having it analyzed he discovered that it contained puffer fish extract, a very powerful poison which, taken in very small doses, if it does not kill, can reduce those who come into contact with it into a trance-like state. He added that the poison is not enough, but to become a zombie a good psychological and cultural predisposition is also needed.
Living dead aside, tetrodotoxin, this is the name of this poison which is much more powerful than cyanide, takes its name from the Tetraodontidae family, fish with 4 teeth fused into a beak, suitable for cutting shells, crustaceans and even coral twigs. Puffer fish, if disturbed, swell into spherical shape, thus enormously increasing their volume to terrify predators. The same characteristic and the same poison are present in the Diodontidae, or porcupine fish, also equipped with spines all over their body.
In Japan, fugu is still served, i.e. puffer fish treated by trained chefs who know how to extract the poison from the meat (gonads, skin, liver, intestines). The secret is to leave enough of that toxin in it to give a slight euphoria and a little tingling to the lips and tongue... but only a quarter of chefs pass the exam, that is, eating their own preparation!
In Japan it is the only delicacy that is forbidden to serve to the emperor and his family. Every year several dozen people in search of thrills lose their minds over a dish that can cost up to 400 euros! One milligram is enough to kill a person. There are no adequate antidotes yet: the toxin blocks nerve conduction causing paralysis, vomiting, diarrhea, convulsions, cardiorespiratory block, etc. so much so that 60% of those poisoned die within a few hours.
Those who survive recover without complications, hence the state of apparent death induced in the "zombies".
Tetrodotoxin is not only found in pufferfish and porcupines, but also in some salamanders, flatworms, frogs and toads, parrotfish, crabs and starfish, algae and molluscs.
The presence of the same poison in many animals that are often evolutionarily very distant is due to the fact that it is not a product of their metabolism, but of microscopic organisms (there is still no agreement among scientists on the species of bacterium involved) that live in symbiosis all over the world inside them. The host is immune to it because natural selection has created a small modification to one of the cellular sodium channel proteins, a molecular deformation sufficient to prevent the tetrodotoxin from attaching like a real plug, obstructing the passage of sodium and therefore the propagation of the nervous impulse.
