Pufferfish, scorpions and black mamba snakes, oh my! These cuddly critters all make toxins affecting the cell membranes of nerve cells. If you haven’t read my last two posts, “Don’t eat pufferfish” and “Your potassium channel,” now would be the time. I’m experimenting here with a three-part series and this post is the last of the three.
Toxins affecting nerve cells, like those produced by pufferfish, scorpions and snakes, are called neurotoxins. Although tetrodotoxin (this is the toxin from pufferfish) is somewhat commonly known, I’m guessing the most prominent neurotoxin is Botox.
Toxin? Yep. Botox is the botulinum toxin. It comes from the Clostridium botulinum bacteria and ranks with tetrodotoxin as one of the most toxic substances out there.
The botulinum toxin has become popular in the medical world because of its ability to paralyze cells. It’s used in minute amounts for cosmetic treatment.
I’m inserting my opinion into this paragraph before I return to the science of Botox. I have mixed feelings about Botox treatment: it’s my frenemy. I am a migraine sufferer, and thus very well understand the plight of chronic migraine sufferers.
I sometimes have luck with pharmaceuticals (i.e. prescribed drugs) and sometimes do not. The appeal of a Botox shot to curb a persistent, debilitating migraine is, thus, not lost upon me. However, Botox is a toxin, and if given incorrectly, could paralyze me. However, here’s a NY Times article from 2009 (pre-FDA approval) that makes me want to try Botox. FRENEMY!
Here’s how Botox works. Let’s say I go to the doctor complaining of a wrinkle in my forehead. The doctor injects a tiny amount of Botox directly into my forehead. She aims to hit the weak muscle underneath my wrinkle. (If the muscle weren’t weak, there would be no wrinkle!)
The toxin, once inside my body, travels to the nerve cell responsible for controlling the weakened muscle. The toxin plugs that nerve cell’s sodium channel. This prevents the nerve cell from talking to its neighbors.
Sound familiar? This is exactly how tetrodotoxin works.
As a result, the cell loses its ability to function. No longer controlled by a functional nerve cell, the muscle relaxes and my wrinkle disappears.
This procedure is an art form. Too little toxin and the wrinkle stays. Too much toxin and we have a repeat performance of what happens from eating pufferfish.
But not all toxins are neurotoxins. In the plant kingdom a toxin works differently.
The black walnut tree produces the drug-like toxin juglone. Juglone is made in the tree’s roots, bark and leaves. Juglone acts as an herbicide to nearby plants. The toxic zone is expansive, extending 50 feet from the base of the tree in every direction.
The juglone toxin wipes out everything in its path. It hits alfalfa plants, tomato plants, apple trees, and [insert your favorite plant or tree]. The attacked plants and trees wilt, and their leaves darken and wither away. The black walnut tree can now eat like a king: it has no competition.
Toxins are carried in a liquid form, either as venom or poison.
If an animal is venomous, the animal will inject venom directly into its prey by biting or stinging.
If an animal is poisonous, the toxin is harmful only if we touch it or eat it or inject it ourselves.
The pufferfish? It’s poisonous. It’s not going to bite us; we have to touch it or eat it.
A scorpion? It’s venomous. It’s sure as heck going to sting us.
The black mamba snake? Venomous. Bite away, snake.
The botulinum bacteria? Poisonous. Ever seen a bacterial cell with teeth? Nope. And no, Dad, Pac-Man does not count.
The black walnut tree’s toxin juglone? Is that poison or venom? Post a comment with your answer!
For those animals that are venomous, mostly scorpions and snakes, our medical advances provide us with anti-venom. The anti-venom protects us from the toxic effects of the venom, and we can avoid getting sick.
What is anti-venom? It’s an antibody to the venom, thanks to the use of research animals. Researchers inject animals, often horses, with venom that harms humans (but not horses). The horse’s body mounts an immune response to the venom, producing antibodies.
Medical researchers then collect the horse’s blood, isolate the antibodies, and voila – anti-venom.
The anti-venom will help snake and scorpion bites. It’s useless against the pufferfish toxin. Don’t. eat. pufferfish.