Return of the Puppet Masters: Ponerological Implications of Toxoplasmosis

The Return of the Puppet Masters
Carl Zimmer
17 Jan 06

Are brain parasites altering the personalities of three billion people? The question emerged a few years ago, and it shows no signs of going away.

I first encountered this idea while working on my book Parasite Rex. I was investigating the remarkable ability parasites have to manipulate the behavior of their hosts. The lancet fluke Dicrocoelium dendriticum, for example, forces its ant host to clamp itself to the tip of grass blades, where a grazing mammal might eat it. It's in the fluke's interest to get eaten, because only by getting into the gut of a sheep or some other grazer can it complete its life cycle. Another fluke, Euhaplorchis californiensis, causes infected fish to shimmy and jump, greatly increasing the chance that wading birds will grab them.

Those parasites were weird enough, but then I got to know Toxoplasma gondii. This single-celled parasite lives in the guts of cats, sheddding eggs that can be picked up by rats and other animals that can just so happen be eaten by cats. Toxoplasma forms cysts throughout its intermediate host's body, including the brain. And yet a Toxoplasma-ridden rat is perfectly healthy. That makes good sense for the parasite, since a cat would not be particularly interested in eating a dead rat. But scientists at Oxford discovered that the parasite changes the rats in one subtle but vital way.

The scientists studied the rats in a six-foot by six-foot outdoor enclosure. They used bricks to turn it into a maze of paths and cells. In each corner of the enclosure they put a nest box along with a bowl of food and water. On each the nests they added a few drops of a particular odor. On one they added the scent of fresh straw bedding, on another the bedding from a rat's nests, on another the scent of rabbit urine, on another, the urine of a cat. When they set healthy rats loose in the enclosure, the animals rooted around curiously and investigated the nests. But when they came across the cat odor, they shied away and never returned to that corner. This was no surprise: the odor of a cat triggers a sudden shift in the chemistry of rat brains that brings on intense anxiety. (When researchers test anti-anxiety drugs on rats, they use a whiff of cat urine to make them panic.) The anxiety attack made the healthy rats shy away from the odor and in general makes them leery of investigating new things. Better to lie low and stay alive.

Then the researchers put Toxoplasma-carrying rats in the enclosure. Rats carrying the parasite are for the most part indistinguishable from healthy ones. They can compete for mates just as well and have no trouble feeding themselves. The only difference, the researchers found, is that they are more likely to get themselves killed. The scent of a cat in the enclosure didn't make them anxious, and they went about their business as if nothing was bothering them. They would explore around the odor at least as often as they did anywhere else in the enclosure. In some cases, they even took a special interest in the spot and came back to it over and over again.

The scientists speculated that Toxoplasma was secreted some substance that was altering the patterns of brain activity in the rats. This manipulation likely evolved through natural selection, since parasites that were more likely to end up in cats would leave more offpsring.

The Oxford scientists knew that humans can be hosts to Toxoplasma, too. People can become infected by its eggs by handling soil or kitty litter. For most people, the infection causes no harm. Only if a person's immune system is weak does Toxoplasma grow uncontrollably. That's why pregnant women are advised not to handle kitty litter, and why toxoplasmosis is a serious risk for people with AIDS. Otherwise, the parasite lives quietly in people's bodies (and brains). It's estimated that about half of all people on Earth are infected with Toxoplasma.

Given that human and rat brains have a lot of similarities (they share the same basic anatomy and use the same neurotransmitters), a question naturally arose: if Toxoplasma can alter the behavior of a rat, could it alter a human? Obviously, this manipulation would not do the parasite any good as an adaptation, since it's pretty rare for a human to be devoured by a cat. But it could still have an effect.

Some scientists believe that Toxoplasma changes the personality of its human hosts, bringing different shifts to men and women. Parasitologist Jaroslav Flegr of Charles University in Prague administered psychological questionnaires to people infected with Toxoplasma and controls. Those infected, he found, show a small, but statistically significant, tendency to be more self-reproaching and insecure. Paradoxically, infected women, on average, tend to be more outgoing and warmhearted than controls, while infected men tend to be more jealous and suspicious.

It's controversial work, disputed by many. But it attracted the attention of E. Fuller Torrey of the Stanley Medical Research Institute in Bethesda, Maryland. Torrey and his colleagues had noticed some intriguing links between Toxoplasma and schizophrenia. Infection with the parasite has been associated with damage to a certain class of neurons (astrocytes). So has schizophrenia. Pregnant women with high levels of Toxoplasma antibodies in their blood were more likely to give birth to children who would later develop schizophrenia. Torrey lays out more links in this 2003 paper. While none is a smoking gun, they are certainly food for thought. It's conceivable that exposure to Toxoplasma causes subtle changes in most people's personality, but in a small minority, it has more devastating effects.

A year later, Torrey and his colleagues discovered one more fascinating link. They raised human cells in Petri dishes and infected them with Toxoplasma. Then they dosed the cells with a variety of drugs used to treat schizophrenia. Several of the drugs--most notably haloperidol--blocked the growth of the parasite.

So Fuller and the Oxford scientists joined forces to find an answer to the next logical question: can drugs used to treat schizophrenia help a parasite-crazed rat? They now report their results in the Proceedings of the Royal Society of London (press release). They ran the original tests on 49 more rats. Once again, parasitized rats lost their healthy fear of cats. Then the researchers treated the rats with haloperidol and several other anti-psychotic drugs. They found that the drugs made the rats more scared. They also found that the antipsychotics were as effective as pyrimethamine, a drug that is specifically used to eliminate Toxoplasma.

There's plenty left to do to turn these results into a full-blown explanation of parasites and personalities. For example, what is Toxoplasma releasing into brains to manipulate its hosts? And how does that substance give rise to schizophrenia in some humans? And even if the hypothesis does hold up, it would only account for some cases of schizophrenia, while the cause of others would remain undiscovered. But still...the idea that parasites are tinkering with humanity's personality--perhaps even giving rise to cultural diversity--is taking over my head like a bad case of Toxoplasma.

Comment: Now this is really scary considering something the C's said almost ten years ago:

9 August 1997
Q: Next question: is there any relationship between the fact that Roger de Mortimer,the carrier of the last of the line of the Welsh kings, was the lover of Isabella of France, who was the daugther of Philip the Fair, the destroyer of the Templars, and the murder of Edward II, the first of the English Prince of Wales?

A: Templars are a setup, insofar as persecution is concerned. Remember your "historical records" can be distorted, in order to throw off future inquiries, such as your own.

Q: I know that. I have already figured that one out! But, it seems that no one else has made this connection. I mean, the bloodlines that converge in the Percys and the Mortimers are incredible!

A: You should know that these bloodlines become parasitically infected, harrassed and tinkered with whenever a quantum leap of awareness is imminent.

Q: Whenever a quantum leap...

A: Such as "now." ... Here is something for you to digest: Why is it that your scientists have overlooked the obvious when they insist that alien beings cannot travel to earth from a distant system???

Q: And what is this obvious thing?

A: Even if speed of light travel, or "faster," were not possible, and it is, of course, there is no reason why an alien race could not construct a space "ark," living for many generations on it. They could travel great distances through time and space, looking for a suitable world for conquest. Upon finding such, they could then install this ark in a distant orbit, build bases upon various solid planes in that solar system, and proceed to patiently manipulate the chosen civilizations to develop a suitable technological infrastructure. And then, after the instituting of a long, slow, and grand mind programming project, simply step in and take it over once the situation was suitable.

Q: Is this, in fact, what has happened, or is happening?

A: It could well be, and maybe now it is the time for you to learn about the details.

Q: Well, would such a race be 3rd or 4th density in orientation?

A: Why not elements of both?

Q: What is the most likely place that such a race would have originated from?

A: Oh, maybe Orion, for example?

Q: Okay. If such a race did, in fact, travel to this location in space/time, how many generations have come and gone on their space ark during this period of travel, assuming, of course, that such a thing has happened?

A: Maybe 12.

Q: Okay, that implies that they have rather extended life spans...

A: Yes...

Q: Assuming this to be the case, what are their lifespans?
A: 2,000 of your years. ... When in space, that is...

Q: And what is the span when on terra firma?
A: 800 years.

Q: Well, has it not occurred to them that staying in space might not be better?

A: No. Planets are much more "comfortable."

Q: Okay... imagining that such a group has traveled here...

A: We told you of upcoming conflicts... Maybe we meant the same as your Bible, and other references. Speak of... The "final" battle between "good and evil..." Sounds a bit cosmic, when you think of it, does it not?

Q: Does this mean that there is more than one group that has traveled here in their space arks?

A: Could well be another approaching, as well as "reinforcements" for either/or, as well as non-involved, but interested observers of various types who appreciate history from the sidelines.

Q: Well, SWELL! There goes my peaceful life!

A: You never had one!

Q: Well, I was planning on one! ... Any other comment?

A: You chose to be incarnated now, with some foreknowledge of what was to come. Reference your dreams of space attack.

Q: Okay, what racial types are we talking about relating to these hypothetical aliens?

A: Three basic constructs. Nordic, Reptilian, and Greys. Many variations of type 3, and 3 variations of type 1 and 2.

Q: Well, what racial types are the 'good guys?'

A: Nordics, in affiliation with 6th density "guides."

Q: And that's the only good guys?

A: That's all you need.

Q: Wonderful! So, if it is a Grey or Lizzie, you know they aren't the nice guys. But, if it is tall and blond, you need to ask questions!

A: All is subjective when it comes to nice and not nice. Some on 2nd density would think of you as "not nice," to say the least!!!

Q: That's for sure! Especially the roaches! Maybe we ought to get in touch with some of these good guys...

A: When the "time" is right.

The Return of The Puppet Masters indeed!
News, Blog, Politics, Life, Ponerology, Current Affairs, Toxoplasmosis, Media,