[NetBehaviour] Toxoplasma Parasite Mind Control

marc marc.garrett at furtherfield.org
Sun Feb 12 19:46:54 CET 2006

Toxoplasma 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 guts 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:

    * 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.


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