The Zombie Protocol, Part 1

     As I mentioned in my previous post, some reports of zombies are more likely observations of people suffering from mental illness, long-term drug abuse, or both.  Given the loose definition of a zombie as somebody "acting strange" who had been missing and presumed dead, one wonders how many urban dwellers and street people in this country might be considered zombies.  I was at a conference in Barbados a few years back and walked past a homeless guy on Broad St. in Bridgetown.  He rose out of a pile of belongings to approach me, his legs stiff and his arms trembling. He was a pitiful sight, and communicated using grunts and various hand gestures.  He wound up following me for a block and even after I crossed the street and doubled back, he was still behind me.  I told everyone back home that I had seen a zombie, no doubt fulfilling my obligation to keep these legends alive.

  But what about "real" zombies? Is there a way to bring someone back from the dead?  Does the Zombie Protocol exist?  Without a doubt, the answer to this is 'yes'.  Although the legend of the zombie has existed in Haiti for generations, there is enough physical evidence to suggest that the process of zombification is likely rooted in scientific fact.  Please ignore the Hollywood ideas of brain-sucking zombies, and think instead about a circus act.  How would somebody make a zombie without learning all that dark magic (which, by all accounts, is very difficult)?  You fake it, but you fake it well.

Tetrodotoxin structure: Note the guanidido group (NH2+)
 group on the left.

In Wade Davis' excellent article The Ethnobiology of the Haitian Zombi (abstract), he lists the composition of zombie poisons from five separate locations around Haiti.  Although there were many differences, based on what was available at the different geographical locations, there were several key ingredients.  One of the most important was the puffer fish (Diodon hystrix, Diodon holacanthus, and others).  Puffer fish in the region have very high levels of tetrodotoxin (TTX), which is, of course, the same toxin found in Japanese fugu fish.  Tetrodotoxins are extremely toxic molecules and act by blocking Na ion channels, presumably through the positively charged guanidido group, which competes for the Na binding site in the channel.  Without Na exchange, nerve impulses do not propagate which leads to paralysis, as well as cardiac and respiratory failure. The LD50 of TTX is estimated to be about 5 ug/kg in humans (less than1 mg of TTX), so what if a person ingested something a little less than that?  Respiratory function decreases, blood pressure drops to near zero, pupils are fixed and dilated, the body is paralyzed, but maybe, just maybe, they won't actually die.  This is the first trick of the Voodoo priests, namely, to make the family think the victim is dead by titrating the amount of puffer fish in the poison to near the LD50.
     What is interesting, and also horrifying, is that TTX does not usually affect cognitive function.  This means that the victim falls ill and becomes "dead" while remaining conscious.  They hear the doctors discussing the death, hear the family wailing in grief, hear the preparations for burial, and then find themselves in a box, quiet and still.  Imagine the terror of being buried alive but having no way to move, scream, or otherwise respond to the panic.  The fear is completely trapped in the victim's mind..  Poe couldn't have scripted that much better...

Next up in the Zombie Protocol, toad toxins and zombie cucumbers...