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?


(Toxoplasma gondii)

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:

  • 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.
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.

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 |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 45 )

Related News Stories - (" Medical ")

Please, Please Let There Be Regenerated Teeth
'Toothbud transplants...' - William Gibson, 1984.

First Biolimb Grown In Lab
A brand-new forelimb for some lucky rat.

Robot Swarm Performs Colonoscopy And Biopsy
'There was ... the Seven Minute Special...'- Neal Stephenson, 1995.

L'Oreal To 3D Print Human Skin
'...She helped the doctor spray on surrogate skin.'- Robert Heinlein, 1951.

 

Google
  Web TechNovelgy.com   

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.

 

 

 

 

 

Current News

Hackers Can Take Control Of Cars From Anywhere In The World
'The car faltered as the external command came to brake...'

Armed Drone Opens Fire
'Each a television eye and a sonic stunner...'

Robotic Exoskeleton Releases Man From Wheelchair
'This man was standing on two corrugated-soled titanium footplates...'

Oh, Just Let Robots Run Airports
I'd like a friendly robot to help me at airports.

How Smart Should AI's Be Allowed To Get?
'Every AI ever built has an electromagnetic shotgun wired to its forehead'

NASA Misses $5Trillion Funding Boost
'This must be a golden planet—this little asteroid.'

Kuwait Creates Mandatory DNA Database For Citizens
And who has the largest DNA database on its citizens?

Please, Please Let There Be Regenerated Teeth
'Toothbud transplants...'

Google AI 'Deep Dreams' Kubrick's 2001
'I was only trying to do what I thought best....'

The BLITAB: First Tactile Tablet for Blind People
Absolutely amazing development - now blind people can read the web!

Why, Oh Why, Must We Develop Robots That Run Faster Than I Do?
'The legs are long, curled way up to deliver power, like a cheetah's.'

Golf Robot Putts Out
'The robot solemnly hit a ball against the wall, picked it up and teed it, hit it again, over and again...'

Computer Finds Cancer Doctors Miss
The computer will see you now.

Would Robot Taxis Ease Carbon Emissions?
'He emerged and flagged down a robot taxi...'

Brainwaves As Biometric Identification
'The doors of Mr. Lars, Incorporated, shut, tuned as they were to his own cephalic pattern.'

What-If Machine Concocts Creative Premises
'Books were just a commodity that had to be produced, like jam or bootlaces.'

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.