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Barry
03-01-2012, 11:15 AM
Maybe this explains a few things...:crazysmile:
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Barry & Rudy


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How Your Cat Is Making You Crazy

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?

By Kathleen McAuliffe (https://www.theatlantic.com/kathleen-mcauliffe/)

https://cdn.theatlantic.com/static/coma/images/issues/201203/mcauliffe-wide.jpg
Michal Novotný

How Your Cat Is Making You Crazy

No one would accuse Jaroslav Flegr of being a conformist. A self-described “sloppy dresser,” the 53-year-old Czech scientist has the contemplative air of someone habitually lost in thought, and his still-youthful, square-jawed face is framed by frizzy red hair that encircles his head like a ring of fire.

Certainly Flegr’s thinking is jarringly unconventional. Starting in the early 1990s, he began to suspect that a single-celled parasite in the protozoan family was subtly manipulating his personality, causing him to behave in strange, often self-destructive ways. And if it was messing with his mind, he reasoned, it was probably doing the same to others.

The parasite, which is excreted by cats in their feces, is called Toxoplasma gondii (T. gondii or Toxo for short) 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.https://cdn.theatlantic.com/static/coma/images/issues/201203/mcauliffe2-200px.jpg
The parasite T. gondii, seen here,
may be changing connections
between our neurones, altering
how we act and feel.
(Dennis Kunkel Microscropy, Inc./
Visuals Unlimited/Corbis Images) T. gondii is also a major threat to people with weakened immunity: in the early days of the AIDS epidemic, before good antiretroviral drugs were developed, it was to blame for the dementia that afflicted many patients at the disease’s end stage. Healthy children and adults, however, usually experience nothing worse than brief flu-like symptoms before quickly fighting off the protozoan, which thereafter lies dormant inside brain cells—or at least that’s the standard medical wisdom.

But if Flegr is right, the “latent” parasite may be quietly tweaking the connections between our neurons, changing our response to frightening situations, our trust in others, how outgoing we are, and even our preference for certain scents. And that’s not all. He also believes that the organism contributes to car crashes, suicides, and mental disorders such as schizophrenia. When you add up all the different ways it can harm us, says Flegr, “Toxoplasma might even kill as many people as malaria, or at least a million people a year.”

An evolutionary biologist at Charles University in Prague, Flegr has pursued this theory for decades in relative obscurity. Because he struggles with English and is not much of a conversationalist even in his native tongue, he rarely travels to scientific conferences. That “may be one of the reasons my theory is not better known,” he says. And, he believes, his views may invite deep-seated opposition. “There is strong psychological resistance to the possibility that human behavior can be influenced by some stupid parasite,” he says. “Nobody likes to feel like a puppet. Reviewers [of my scientific papers] may have been offended.” Another more obvious reason for resistance, of course, is that Flegr’s notions sound an awful lot like fringe science, right up there with UFO sightings and claims of dolphins telepathically communicating with humans.

But after years of being ignored or discounted, Flegr is starting to gain respectability. Psychedelic as his claims may sound, many researchers, including such big names in neuroscience as Stanford’s Robert Sapolsky, think he could well be onto something. Flegr’s “studies are well conducted, and I can see no reason to doubt them,” Sapolsky tells me. Indeed, recent findings from Sapolsky’s lab and British groups suggest that the parasite is capable of extraordinary shenanigans. T. gondii, reports Sapolsky, can turn a rat’s strong innate aversion to cats into an attraction, luring it into the jaws of its No. 1 predator. Even more amazing is how it does this: the organism rewires circuits in parts of the brain that deal with such primal emotions as fear, anxiety, and sexual arousal. “Overall,” says Sapolsky, “this is wild, bizarre neurobiology.” Another academic heavyweight who takes Flegr seriously is the schizophrenia expert E. Fuller Torrey, director of the Stanley Medical Research Institute, in Maryland. “I admire Jaroslav for doing [this research],” he says. “It’s obviously not politically correct, in the sense that not many labs are doing it. He’s done it mostly on his own, with very little support. I think it bears looking at. I find it completely credible.”

What’s more, many experts think T. gondii may be far from the only microscopic puppeteer capable of pulling our strings. “My guess is that there are scads more examples of this going on in mammals, with parasites we’ve never even heard of,” says Sapolsky.

Familiar to most of us, of course, is the rabies virus. On the verge of killing a dog, bat, or other warm-blooded host, it stirs the animal into a rage while simultaneously migrating from the nervous system to the creature’s saliva, ensuring that when the host bites, the virus will live on in a new carrier. But aside from rabies, stories of parasites commandeering the behavior of large-brained mammals are rare. The far more common victims of parasitic mind control—at least the ones we know about—are fish, crustaceans, and legions of insects, according to Janice Moore, a behavioral biologist at Colorado State University. “Flies, ants, caterpillars, wasps, you name it—there are truckloads of them behaving weirdly as a result of parasites,” she says.

Consider Polysphincta gutfreundi, a parasitic wasp that grabs hold of an orb spider and attaches a tiny egg to its belly. A wormlike larva emerges from the egg, and then releases chemicals that prompt the spider to abandon weaving its familiar spiral web and instead spin its silk thread into a special pattern that will hold the cocoon in which the larva matures. The “possessed” spider even crochets a specific geometric design in the net, camouflaging the cocoon from the wasp’s predators.

Flegr himself traces his life’s work to another master of mind control. Almost 30 years ago, as he was reading a book by the British evolutionary biologist Richard Dawkins, Flegr was captivated by a passage describing how a flatworm turns an ant into its slave by invading the ant’s nervous system. A drop in temperature normally causes ants to head underground, but the infected insect instead climbs to the top of a blade of grass and clamps down on it, becoming easy prey for a grazing sheep. “Its mandibles actually become locked in that position, so there’s nothing the ant can do except hang there in the air,” says Flegr. The sheep grazes on the grass and eats the ant; the worm gains entrance into the ungulate’s gut, which is exactly where it needs to be in order to complete—as the Lion King song goes—the circle of life. “It was the first I learned about this kind of manipulation, so it made a big impression on me,” Flegr says.

After he read the book, Flegr began to make a connection that, he readily admits, others might find crazy: his behavior, he noticed, shared similarities with that of the reckless ant. For example, he says, he thought nothing of crossing the street in the middle of dense traffic, “and if cars honked at me, I didn’t jump out of the way.” He also made no effort to hide his scorn for the Communists who ruled Czechoslovakia for most of his early adulthood. “It was very risky to openly speak your mind at that time,” he says. “I was lucky I wasn’t imprisoned.” And during a research stint in eastern Turkey, when the strife-torn region frequently erupted in gunfire, he recalls being “very calm.” In contrast, he says, “my colleagues were terrified. I wondered what was wrong with myself.”

His bewilderment continued until 1990, when he joined the biology faculty of Charles University. As it happened, the 650-year-old institution had long been a world leader in documenting the health effects of T. gondii, as well as developing methods for detecting the parasite. In fact, just as Flegr was arriving, his colleagues were searching for infected individuals on whom to test their improved diagnostic kits, which is how he came to be asked one day to roll up his sleeve and donate blood. He discovered that he had the parasite—and just possibly, he thought, the key to his baffling self-destructive streak.

He delved into T. gondii’s life cycle. After an infected cat defecates, Flegr learned, the parasite is typically picked up from the soil by scavenging or grazing animals—notably rodents, pigs, and cattle—all of which then harbor it in their brain and other body tissues. Humans, on the other hand, are exposed not only by coming into contact with litter boxes, but also, he found, by drinking water contaminated with cat feces, eating unwashed vegetables, or, especially in Europe, by consuming raw or undercooked meat. Hence the French, according to Flegr, with their love of steak prepared saignant—literally, “bleeding”—can have infection rates as high as 55 percent. (Americans will be happy to hear that the parasite resides in far fewer of them, though a still substantial portion: 10 to 20 percent.) Once inside an animal or human host, the parasite then needs to get back into the cat, the only place where it can sexually reproduce—and this is when, Flegr believed, behavioral manipulation might come into play.

Continues here (https://www.theatlantic.com/magazine/archive/2012/03/how-your-cat-is-making-you-crazy/8873/?single_page=true).

podfish
03-03-2012, 08:21 AM
Maybe this explains a few things...:crazysmile:
Barry & Rudy
How Your Cat Is Making You Crazy
... he began to suspect that a single-celled parasite in the protozoan family was subtly manipulating his personality, causing him to behave in strange, often self-destructive way a little flouride would fix that right up.

Hotspring 44
07-03-2012, 10:43 PM
:jawdrop::kitty:
Study Links Cat Litter Box to Increased Suicide Risk (https://gma.yahoo.com/study-links-cat-litter-box-increased-suicide-risk-194116398--abc-news-health.html)

By SUSAN DONALDSON JAMES | Good Morning America

A common parasite that can lurk in the cat litter box may cause undetected brain changes in women that make them more prone to suicide, according to an international study.

Scientists have long known that pregnant women infected with the toxoplasma gondii parasite -- spread through cat feces, undercooked meat or unwashed vegetables -- could risk still birth or brain damage if transmitted to an unborn infant.

But a new study of more than 45,000 women in Denmark shows changes in their own brains after being infected by the common parasite.

The study, authored by University of Maryland School of Medicine psychiatrist and suicide neuroimmunology expert Dr. Teodor T. Postolache, was published online today in the Archives of General Psychiatry.

The study found that women infected with T. gondii were one and a half times more likely to attempt suicide than those who were not infected. As the level of antibodies in the blood rose, so did the suicide risk. The relative risk was even higher for violent suicide attempts.

"We can't say with certainty that T. gondii caused the women to try to kill themselves, but we did find a predictive association between the infection and suicide attempts later in life that warrants additional studies," said Postolache, who is director of the university's Mood and Anxiety Program and is a senior consultant on suicide prevention.

"There is still a lot we don't know," he told ABCNews.com. "We need a larger cohort and need a better understanding of the vulnerabilities that certain people have to the parasite."

Suicide is a global public health problem. An estimated 10 million attempt suicide and 1 million are successful, according to Postlache's work.

More than 60 million men, women, and children in the United States carry the toxoplasma parasite, according to the Centers for Disease Control and Prevention, but very few have symptoms.

Toxoplasmosis is considered one of the "neglected parasitic infections," a group of five parasitic diseases that have been targeted by CDC for public health action.

About one-third of the world is exposed to T. gondii, and most never experience symptoms and therefore don't know they have been infected. When humans ingest the parasite, the organism spreads from the intestine to the muscles and the brain.

Previous research on rodents shows that the parasite can reside in multiple brain structures, including the amygdala and the prefrontal cortex, which are responsible for emotional and behavioral regulation.
Rat Study Showed Parasite Changes the Brain

A 2011 study on rats infected by the parasite showed that their fear of cats disappeared. Instead, the parts of their brains associated with sexual arousal were activated. Researchers theorized that the mind-manipulating T. gondii ensures that the parasite will reach and reproduce in the gut of a cat, which it depends upon for its survival.

"The parasite does actually alter the brain of its host," Stanford University study co-author Patrick House told ABCNews.com last year. "The fact that a parasite can get into an organism, target its brain, stay there without killing the host and alter the circuitry of the brain -- we've seen this is insects and fungi, but it's the first time we've seen it in a mammalian host."

It was this and other research that led Postolache to investigate the relationship between the parasite and biological changes in the brain that might lead to suicide. He was also intrigued by studies on allergies and research that showed a connection between toxoplasmosis and schizophrenia.

"I was interested in the neuron aspects of suicide and intrigued by low-grade activation in patients who attempted suicide, as well as victims," he said. "Other studies had looked at the brain and suicide risk and impulsivity. The next question was, what could be the triggers that perpetuate this level of heightened activation in the brain?"

Postolache collaborated with Danish, German and Swedish researchers, using the Danish Cause of Death Register, which logs the causes of all deaths, including suicide. The Danish National Hospital Register was also a source of medical histories on those subjects.

They analyzed data from women who gave birth between 1992 and 1995 and whose babies were screened for T. gondii antibodies. It takes three months for antibodies to develop in babies, so when they were present, it meant their mothers had been infected.

The scientists then cross-checked the death registry to see if these women later killed themselves. They used psychiatric records to rule out women with histories of mental illness.

Postolache said there were limitations to the study and further research is needed, particularly with a larger subject group.

Dr. J. John Mann, a psychiatrist from Columbia University, said Postolache's research mirrors his work in the field of suicidal behavior.

"The relationship of the brain to the immune system is more complex than it may appear," said Mann. "The brain regulates the stress response system, which impacts the immune response."

Scientists already know that steroids like cortisone can affect the immune response. Some antibodies whose goal is to kill off cancer can also affect the brain. Oftentimes the first symptom of pancreatic cancer is depression, he said.

Research also shows that streptococcus bacteria can trigger obsessive-compulsive disorder (OCD) in some children. Sydenham's chorea, the loss of motor control that can occur after acute rheumatic fever, may also be an immune response affecting the brain, according to Mann.

Maryland researcher Postolache suspects that some individuals have a predisposition to these neurological changes.

He speculates that the parasite may disrupt neurological pathways in those who are vulnerable, so that projections of fear and depression from the amygdala are not tempered or controlled by the "braking" function of the prefrontal cortex.

But, Postolache warns that even if a direct cause were found, no antibiotics for T. gondii yet exist and it could be a decade before effective vaccines or other agents that might stop the neurological damage are developed.

Right now, the most effective weapon against T. gondii is education about handwashing, the proper cooking of food, and not using a knife exposed to raw meat on cooked meat.

He also cautions against trendy food production techniques that let animals roam free. "The risk of infection could go up," he said, "and increase the rate of toxoplasmosis."