Toxoplasma Gondii Parasite Mind Control
Half of the world's human population is infected with Toxoplasma. Parasites in the body - and the brain. Remember that.
Toxoplasma gondii is a common parasite found in the gut of cats; it sheds eggs that are picked up by rats and other animals that are eaten by cats. Toxoplasma forms cysts in the bodies of the intermediate rat hosts, including the brain. Since cats don't want to eat dead, decaying prey, Toxoplasma takes the evolutionarily sound course of being a "good" parasite, leaving the rats perfectly healthy. Or are they?
Oxford scientists discovered that the minds of the infected rats have been subtly altered. In a series of experiments, they demonstrated that healthy rats will prudently avoid areas that have been doused with cat urine. In fact, when scientists test anti-anxiety drugs on rats, they use a whiff of cat urine to induce neurochemical panic. However, it turns out that Toxoplasma-ridden rats show no such reaction. In fact, some of the infected rats actually seek out the cat urine-marked areas again and again. The parasite alters the mind (and thus the behavior) of the rat for its own benefit.
If the parasite can alter rat behavior, does it have any effect on humans? Dr. E. Fuller Torrey (Associate Director for Laboratory Research at the Stanley Medical Research Institute) noticed links between Toxoplasma and schizophrenia in human beings, approximately three billion of whom are infected with T. gondii:
Dr. Torrey got together with the Oxford scientists, to see if anything could be done about those parasite-controlled rats who were driven to hang around cat urine-soaked corners (waiting for cats). According to a recent press release, it turns out that haloperidol restores the rat's healthy fear of cat urine. In fact, antipsychotic drugs were as effective as pyrimethamine, a drug that specifically eliminates Toxoplasma.
- Toxoplasma infection is associated with damage to astrocytes, glial cells which surround and support neurons. Schizophrenia is also associated with damage to astrocytes.
- Pregnant women with high levels of antibodies to Toxoplasma are more likely to give birth to children who will develop schizophrenia.
- Human cells raised in petri dishes, and infected with Toxoplasma, will respond to drugs like haloperidol; the growth of the parasite stops. Haloperidol is an antipsychotic, used to treat schizophrenia.
Are parasites like Toxoplasma subtly altering human behavior? As it turns out, science fiction writers have been thinking about whether or not parasites could alter a human being's behavior, or even take control of a person. In his 1951 novel The Puppet Masters, Robert Heinlein wrote about alien parasites the size of dinner plates that took control of the minds of their hosts, flooding their brains with neurochemicals. In this excerpt, a volunteer strapped to a chair allows a parasite to be introduced; the parasite rides him, taking over his mind. Under these conditions, it is possible to interview the parasite; however, it refuses to answer until zapped with a cattle prod.
He reached past my shoulders with a rod. I felt a shocking, unbearable pain. The room blacked out as
if a switch had been thrown.. I was split apart
by it; for the moment I was masterless.
The pain left, leaving only its searing memory behind. Before I could speak, or even think coherently
for myself, the splitting away had ended and I was again safe in the arms of my master...
The panic that possessed me washed away; I was again filled with an unworried sense of well being...
"What are you?"
"We are the people... We have studied you and we know your ways... We come," I went on, "to bring you peace.. and contentment-and the joy of-of surrender." I hesitated again; "surrender" was not the right word. I struggled with it the way one struggles with a poorly grasped foreign language.
"The joy," I repeated, "-the joy of . . .nirvana." That was it; the word fitted. I felt like a dog being patted
for fetching a stick; I wriggled with pleasure.
Still not sure that parasites can manipulate the behavior of host organisms? Consider these other cases:
- The lancet fluke Dicrocoelium dendriticum forces its ant host to attach to the tips of grass blades, the easier to be eaten. The fluke needs to get into the gut of a grazing animal to complete its life cycle.
- The fluke Euhaplorchis californiensis causes fish to shimmy and jump so wading birds will grab them and eat them, for the same reason.
- Hairworms, which live inside grasshoppers, sabotage the grasshopper's central nervous system, forcing them to jump into pools of water, drowning themselves. Hairworms then swim away from their hapless hosts to continue their life cycle.
Not all science-fictional parasites are harmful; read about the Crosswell tapeworm from Brian Aldiss' 1969 story Super-Toys Last All Summer Long, which keeps people who overeat from becoming obese. Not to mention robots based on parasites. Read press release on evidence for link between Toxoplasma and schizophrenia, Suicidal grasshoppers. Story via blogger
Carl Zimmer and his readers.
Scroll down for more stories in the same category. (Story submitted 2/7/2006)
Follow this kind of news @Technovelgy.
| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |
you like to contribute a story tip?
Get the URL of the story, and the related sf author, and add
Comment/Join discussion ( 45 )
Related News Stories -
AliveCor App Detects Heart Arrhythmias, Has FDA Approval
Works on humans and puppeteers.
Artificial Wombs - Ectogenesis Technology - Is On The Way
'Magnificent, aren't they? (Lama Su, in Star Wars II)
Bionic Hand Provides 'Lifelike' Sensations, Like Luke Skywalker's
A fictional scene becomes reality in just thirty-five years.
Neural Implant To Treat Memory Loss
'You've got remote storage. How regular is the update?'- Richard Morgan, 2003.
Technovelgy (that's tech-novel-gee!)
is devoted to the creative science inventions and ideas of sf authors. Look for
the Invention Category that interests
you, the Glossary, the Invention
Timeline, or see what's New.
'Hello, Computer!' Intel's Core M Catches Up To Scotty
'Well, isn't that quaint!'
Visual Speech Recognition - When Will HAL Read Lips For Real?
Automating lip reading.
MIT's Robotic Cheetah Runs Free - And Frolics In The Grass
'THEY sent A SLAMHOUND on Turner's trail...'
Flying Robot Has An Arm
Drones with arms.
Strati 3D Printed Car
'You rode in it - you know how good it is.'
Tracking Spinning Space Junk
'Loose nuts and bolts... had been accumulating in Earth orbit'
Baidu Kuaisou Dune Poison Snooper Chopsticks
'Unobtrusive inspections with... snoopers... Will it be chaumas - poison in the food?'
Crystalized Light Created At Princeton
'It will be matter, matter made of light...'
The Amazing Gravity-Assisted Journey Of Rosetta
'...We used the [moon's] attraction to give us additional starting speed'
AirDog Auto-Follow Drone Captures Your Awesomeness
'Tight mid-shot and pull out on but behind me...'
Dell's Venue 8 7000 Tablet With RealSense Depth-Mapping
Focus on any part of a picture later.
Google's Cartographer Backpack For Indoor Mapping
'He reached to unsnap the cartograph from his belt.'
T-Mobile Sues Huawei Over Button Pushing Robot Idea From The 1930's
'Not the slightest change in their working betrayed the fact that they were now being directed by a machine instead of human beings.'
Hayabusa-2 Asteroid Cannon Strategy From 1950's SF Novel
'Fire streaked in a thin line from the muzzle of a cannon-like tube...'
Dyson 360 Eye Robot Vacuum Cleaner
'It vacuum-cleaned... or polished, consulting tapes in its idiot memory to decide which.'
First 3D Printer In Space?
'It can be mass-produced only in the orbiting factories...'
More SF in the News Stories
More Beyond Technovelgy science news stories