Besides the ones in Washington, I mean. Science writer Ed Yong addresses the behavioral impact of parasites in this short but fascinating TED Talk.
Tag Archives | Parasites
Yet another study suggests that our anti-septic lifestyle may be causing some health problems while preventing others. It turns out that wormy monkeys (Anyone looking for a band name?) have healthier guts than their worm-free peers:
In developed countries, we’ve mostly eliminated freeloaders like parasitic worms from our guts. But we also have the highest rates of inflammatory bowel disease, or IBD—when the immune system mistakenly attacks intestinal cells and friendly gut bacteria.
For years, docs suspected there might be a connection between IBD and our worm-free lifestyle. And a handful of studies have actually shown that infecting human patients with worms can reduce symptoms of the disease. But how?
Via the mermaid’s tale:
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Rats infected with the parasite Toxoplasma gondii do crazy things. They find the scent of cat urine sexy and attractive, they don’t run from the actual beasts; they are more active in running wheels, which might indicate that the parasite induces increased activity which may more readily attract a cat’s attention. When an infected rat is eaten by a cat, the T. gondii is passed on in the cat’s feces to infect again. T. gondii can only reproduce inside the cat. Great survival strategy on the part of the parasite, this trick of making the rat no longer fear cats — now that’s really building a better mouse-trap! Did this strategy evolve by adaptive selection, or is it just something that happened?
Czech biologist, Jaroslav Flegr, thinks T. gondii infections do much the same to humans — his story is told in the March 2012 Atlantic Monthly.
Is a microscopic, mind-altering parasite spread by cats responsible for car accidents, hoarding behaviors, and schizophrenia? Respected scientists are now saying that “crazy cat lady” disease is real and millions of people are infected. Shocker from Kathleen McAuliffe in the Atlantic:
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Jaroslav Flegr is no kook. And yet, for years, he suspected his mind had been taken over by parasites that had invaded his brain. So the prolific biologist took his science-fiction hunch into the lab. What he’s now discovering will startle you. Could tiny organisms carried by house cats be creeping into our brains, causing everything from car wrecks to schizophrenia?
The parasite, which is excreted by cats in their feces, is called Toxoplasma gondii and is the microbe that causes toxoplasmosis — the reason pregnant women are told to avoid cats’ litter boxes. Since the 1920s, doctors have recognized that a woman who becomes infected during pregnancy can transmit the disease to the fetus, in some cases resulting in severe brain damage or death.
You may not be alone…via CBS News:
Three-year-old Isbac Pacunda absorbed his twin brother as they developed in their mother’s womb. The result? A parasitic twin in the stomach of the living boy.
The partially formed fetus weighs a pound and a half and is 9 inches long, according to Dr. Carlos Astocondor of Las Mercedes Hospital in Chiclayo, Peru. Doctors in Peru found the parasitic twin and planned to surgically remove the tissue Monday. It has some hair on the cranium, eyes and some bones.
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When a male rat senses the presence of a fetching female rat, a certain region of his brain lights up with neural activity, in anticipation of romance. Now Stanford University researchers have discovered that in male rats infected with the parasite Toxoplasma, the same region responds just as strongly to the odor of cat urine. Is it time to dim the lights and cue the Rachmaninoff for some cross-species canoodling?
“Well, we see activity in the pathway that normally controls how male rats respond to female rats, so it’s possible the behavior we are seeing in response to cat urine is sexual attraction behavior, but we don’t know that,” said Patrick House, a PhD candidate in neuroscience in the School of Medicine. “I would not say that they are definitively attracted, but they are certainly less afraid. Regardless, seeing activity in the attraction pathway is bizarre.”
For a rat, fear of cats is rational.
James Curcio writes:
As was reported previously on Disinfo, there has been much recent inquiry into the idea of our sense of consciousness and agency arising through the interaction of things outside our nervous system, such as bacteria in our stomach:
“The wave of the future is full of opportunity as we think about how microbiota or bacteria influence the brain and how the bi-directional communication of the body and the brain influence metabolic disorders, such as obesity and diabetes,” says Jane Foster, associate professor in the Department of Psychiatry and Behavioural Neurosciences of the Michael G. DeGroote School of Medicine.” ( article.)
This, however, is just one example of “control from afar,” and we see plenty of Manchurian Candidate material in the natural world through parasites, fungus, and bacteria that can selectively control animals to essentially do their bidding at the time and place of their leisure:
Fast-spreading parasite species force sex changes on their victims, induce virgin births, and turn animals into "gross monsters" — among other horrors. Now a new study has decoded how the bacteria may be able to wreak their havoc: by shutting down immune systems. The parasites, of the Wolbachia bacteria genus, cause a gene in wasps to stifle the insect's protein-based "alarms" against the bacterial invaders, say researchers who mapped the genomes of three species of Nasonia wasp for the first time. As a result, the wasps' antibacterial defenses are never deployed, allowing Wolbachia to begin their dirty work.