Real Life Zombies

Fungus Makes Zombie Ants Do All the Work
A tropical fungus has adapted to infect ants and force them to chomp, with surprising specificity, into perfectly located leaves before killing them and taking over their bodies

fungus-makes-zombie-ants_1.jpg

ANT COLONIZED: A mature O. unilateralis growing from an ant it has killed a few weeks before. The "P" points out the perithecial plates where spores are released.
Image: THE AMERICAN NATURALIST/ UNIVERSITY OF CHICAGO PRESS


Problem: you’re a fungus that can only flourish at a certain temperature, humidity, location and distance from the ground but can’t do the legwork to find that perfect spot yourself. Solution: hijack an ant’s body to do the work for you—and then inhabit it.

A paper, to be published in The American Naturalist’s September issue, explores the astounding accuracy with which this fungus compels ants to create its ideal home.

The Ophiocordyceps unilateralis fungus infects Camponotus leonardi ants that live in tropical rainforest trees. Once infected, the spore-possessed ant will climb down from its normal habitat and bite down, with what the authors call a "death grip" on a leaf and then die. But the story doesn’t end there.

"The death grip occurred in very precise locations," the authors write. All of the C. leonardi ants studied in Thailand’s Khao Chong Wildlife Sanctuary had chomped down on the underside of a leaf, and 98 percent had landed on a vein. Most had: a) found their way to the north side of the plant, b) chomped on a leaf about 25 centimeters above the ground, c) selected a leaf in an environment with 94 to 95 percent humidity and d) ended up in a location with temperatures between 20 and 30 degrees Celsius. The researchers called this specificity "remarkable."

In other words, the fungus was transported via the zombie ant to its prime location. To see just how important this accuracy is to the fungus, the researchers identified dozens of infected ants in a small area of the forest. Some of the ants were moved to other nearby heights and locations, and others were left to sprout spores just where they had died.

Those ants that were left where O. unilateralis directed them grew normal, healthy hyphae (fungal threads) within several days, but those that had been moved never did.

"I cannot think of another example [of adaptive behavioral changes] as specific as this one," Edward Levri, who has studied behavioral changes in parasite hosts but was not involved in this study, wrote in an e-mail. "The fact that infected individuals all die in a 'lock-jawed' position, at 25 centimeters above ground, mostly on the north side of the tree is amazing and suggests that multiple behaviors and possibly multiple manipulatory physiological mechanisms may be required by the parasite."

The authors also examined the impact of the fungus on an ant in the Polyrhachis genus and found that not all of the behaviors carried over. "The fact that infection by this parasite in another ant species results in some behavioral change, but results in less optimal behavior for the parasite, points to the idea that this parasite has evolved to manipulate this specific host," noted Levri, who is an assistant professor of biology at Penn State Altoona.

Fungus Makes Zombie Ants Do All the Work: Scientific American


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Cat poop parasite controls minds early -- and permanently, study finds

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A parasite that changes the brains of rats and mice so that they are attracted to cats and cat urine seems to work its magic almost right away, and continues to control the brain even after it’s gone, researchers reported on Wednesday.

The mind-controlling parasite, called Toxoplasma gondii, might make permanent changes in brain function as soon as it gets in there, the researchers report. They aren’t sure how yet.

“The parasite is able to create this behavior change as early as three weeks after infection,” says Wendy Ingram of the University of California, Berkeley, who worked on the study.

T. gondii has captured the imaginations of scientists and cat lovers ever since it was learned it can control the behavior of rodents. It changes their brains so they lose their innate fear of the smell of cat urine. In fact, it precisely alters their fear reaction so that they love the smell of cat pee.

This makes infected rodents much more likely to be caught by cats, which eat them and their mind-controlling parasites. T. gondii can only reproduce in the guts of cats, so its behavior directly affects its own survival.

It doesn’t just affect cats. People can be infected too -- pregnant women are told to stay away from cat feces for this very reason. It normally doesn’t bother people, but it can cause brain inflammation, called encephalitis, in some -- especially those with compromised immune systems like pregnant women.

“More than 60 million men, women, and children in the U.S. carry the Toxoplasma parasite, but very few have symptoms because the immune system usually keeps the parasite from causing illness,” the Centers for Disease Control and Prevention says on its website.


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Chronic infection with the parasite Toxoplasma gondii can make mice lose their innate, hard-wired fear of cats.
Wendy Ingram and Adrienne Greene / University of California Berkeley


Chronic infection with the parasite Toxoplasma gondii can make mice lose their innate, hard-wired fear of cats.
Studies have linked toxoplasmosis with a range of human mental diseases, including schizophrenia, bipolar disease, obsessive compulsive disorder and even clumsiness. This study doesn’t answer questions about people, Ingram points out.

“It does not necessarily explain crazy cat ladies or why there are LOLCATS online,” she says.

But it does begin to hint at a potential mechanism for how and when the parasite changes the mouse brains.

“I want to know how the behavioral change is happening,” Ingram says.

Her team used a specially genetically engineered version of the parasite, made by a team at Stanford University.

Normal T. gondii parasites form a cyst in neurons. “It was assumed that the cysts … were doing something biologically that is actively changing the behavior,” Ingram told NBC News.

But the genetically engineered parasite wasn’t able to make cysts. And it was so weak that the rats’ immune systems were able to clear it from their brains. But even so, rats infected with this weakened form of the parasite just loved the smell of cat urine, Ingram and colleagues report in the Public Library of Science journal PLoS ONE.

“This suggests the parasite is flipping a switch rather than continually changing the behavior,” says Ingram.

She suspects it’s somehow activating the immune system in a way that then alters brain function. “That’s one of the very first things I am going to be checking,” Ingram says.

Cat poop parasite controls minds early -- and permanently, study finds - NBC News.com
 

Bowlander

Old-Salt
BMC Infectious Diseases | Full text | Increased incidence of traffic accidents in Toxoplasma-infected military drivers and protective effect RhD molecule revealed by a large-scale prospective cohort study.

http://www.biomedcentral.com/1471-2334/9/72

Interesting stuff - parasite needs to get from human into lion so makes them less risk averse and so more likely to get predated. I knew this happened in water shrimp and ducks but not humans.


Sent from my GT-I9505 using Xparent Green Tapatalk 2
 
Old hat, really. Here's a report that has clearly been plagiarized by the authors of your reference ...
A parasite that changes the brains of humans and squaddies so that they are attracted to gwars and fox piss seems to work its magic almost right away, and continues to control the brain even after it’s gone, researchers reported on Wednesday.

The mind-controlling parasite, called beer, might make permanent changes in brain function as soon as it gets in there, the researchers report. They aren’t sure how yet but are applying for a grant to continue long term studies at the Rose and Crown.
 
BMC Infectious Diseases | Full text | Increased incidence of traffic accidents in Toxoplasma-infected military drivers and protective effect RhD molecule revealed by a large-scale prospective cohort study.

BMC Infectious Diseases | Full text | Increased incidence of traffic accidents in Toxoplasma-infected military drivers and protective effect RhD molecule revealed by a large-scale prospective cohort study

Interesting stuff - parasite needs to get from human into lion so makes them less risk averse and so more likely to get predated. I knew this happened in water shrimp and ducks but not humans.


Sent from my GT-I9505 using Xparent Green Tapatalk 2

Yikes. :shock: makes you wonder what else is subject to parasitic behaviour (not just government).

Good to see ya back Corgs.
 
M

Mark The Convict

Guest
These diseases have already taken virtual form - much of the otherwise inexplicable activity on ARRSE proves it.
 
I work with the public, I know they're all mindless, useless, inbred ******* mongs.

Better get the pick helve dusted off I guess.
 
Women amaze me at times. One had me in stitches the other night. When I stopped laughing I looked in her eyes and could swear she had consciousness. Makes you think twice about the plausibility of AI.
 
M

Mark The Convict

Guest
I was forced to use a public toilet in town this morning, but clearly the zombies had beaten me to it. Luckily I avoided fellating any of them. Ish.
 
We are all zombies actually...a human being is a collection of mindless cells that cooperate to get what they want. Free will is an illusion...:omg:
 
We are all zombies actually...a human being is a collection of mindless cells that cooperate to get what they want. Free will is an illusion...:omg:

So it's your mindlessness that makes you post shite like the above? I have no free will to disbelieve this, really.

I take it you've never heard of emergent properties then.
 
So it's your mindlessness that makes you post shite like the above? I have no free will to disbelieve this, really.

Precacltly...I have no choice at all...honest!

I take it you've never heard of emergent properties then.

Of course I have...My brother in-law purchased a villa in Cyprus earlier this year actuallerum.

But anyway my Mum told me that we now can say with considerable confidence that the universe is not a Newtonian world machine. The Heisenberg uncertainty principle of quantum mechanics showed that, deep down, nature is fundamentally indeterministic. But does quantum indeterminacy play an important role in the brain, and thus open a way for free will? Probably not, and here's why.

The moving parts of the brain are heavy by microscopic standards and move around at relatively high speeds because the brain is hot. Furthermore, the distances involved are large by these same microscopic standards. It is easy to demonstrate quantitatively that quantum effects in the brain are not significant. So, even though libertarians are correct that determinism is false at the microphysical, quantum level, the brain is for all practical purposes a deterministic Newtonian machine, so we don't have free will as they define it.

Although the brain is likely deterministic when it comes to the control of behaviour, there's plenty of "pseudo-randomness" (as opposed to "pure" quantum randomness) in the thermal motions of our brains and in the environment that feeds us data. It's possible that this can provide sufficient uncertainty to give us the "feeling" of free will. Or, perhaps uncertainty plays no direct role and it is simply our lack of awareness about what causes our decisions that we interpret as being exempt from the causal laws of nature. Either way, this means that ultimately we do not have libertarian free will, even though we might be under the impression we do.

I can't do anything without a reason...nor can anyone.


 
Women amaze me at times. One had me in stitches the other night. When I stopped laughing I looked in her eyes and could swear she had consciousness. Makes you think think twice about the plausibility of AI.

Interesting idea.. A Turing Test for women.

Wouldn't have worked on Maggie Thatcher though.

The Lady's not for Turing.

Taxi!
 

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