Tuesday, June 20, 2006

There's Probably a Bug in Your Brain that Wants a Lion to Eat You.

On average I have one hundred visitors to my blog each week. Of those, fifty of them are infected by a parasite called Toxoplasma. And boy is this an interesting little bug.

It is a cellular parasite which, surprisingly, infects half of the world population. Fortunately for us, it is a benign parasite and does little to no damage to us. Basically, it works like this: you introduce the parasite into your body through your digestive tract, and the parasite is absorbed into your blood stream. Once it gets into your blood stream it is found by your immunity cells. When an immunity cell gets close, the Toxoplasm cell jumps on its back. The immunity cell goes "Hey what are you doing there?" And buries himself, hibernating so that he doesn't go off infecting the whole body. Eventually this becomes a benign cyst, and the host never notices anything wrong. The parasite can infect us in pretty much any organ, but it especially likes to make a home in our brains. But don't worry, if you are a host, and the chances are pretty good that you are, you'll probably never know.

So, what's the interesting thing? Well, Toxoplasma is only able to make babies in the intestines of cats. That means in order to procreate, the parasite needs to somehow get inside of cats. But, cats don't eat their own feces, so the parasite won't propogate if it stays in the cat's feces. Mice do eat cat dung however, and cats eat mice. So, the parasite works itself to stay alive inside of mice until a cat eats the mouse. Trouble is: cats don't eat dead things. So, if the parasite kills the mouse, the cat won't eat it and the parasite won't procreate. Instead, the parasite lives inside the mouse (or any other animal) without killing it, waiting for a cat to come by and eat the live, infected mouse. But that's not all. If you think the parasite is clever for living benignly inside of the food that cats eat... wait for this. Here comes the interesting thing: when the parasite is found in mice and rats, they become attracted to the smell of cats!

That's right. Scientists have studied infected mice and rats and have found that infected mice and rats, which instinctually run from the smell of cats, start actually running toward the smell! They don't loose their fear of dogs, and they don't gain fear of rabbits or anything like that. Only their fear of cats is affected by the parasite. It appears as though there is a place in the brain where mice and rats store their instinct to run from cats. Somehow, the parasite seeks out that place and becomes a cyst on that part of the brain. Rats and mice then become attracted to the smell, meaning cats come and eat the infected rat or mouse. The cat then becomes infected, and now the little guys can finally make babies in the cat that caught the mouse that ate the pooh.



It's a pretty complicated but incredibly interesting life cycle if you ask me. And seeing as you are probably infected by the little bugger, I figured I'd let you know about it. Afterall, to the parasite, you're nothing but a big, big mouse. Remember, tigers and lions are cats, and the parasite will procreate just as well inside of tigers and lions. And, tigers and lions both eat people. I guess that means that half of the people in the world have a little bug in their brains that's trying to feed them to the loins...

3 comments:

Tim 2 said...

mmmmm a post about parasites, cat crap, and mice...

I am going to eat dinner now.

PretaMulatta said...

ok so wait a second.
does that mean if i come in & constantly kiss my kitty everyday after work, i can REALLY get a brainbug?

*whines*

Joshua said...

Actually, I think what I'm saying is that you probably already have a brainbug.

Sorry.