How your cat is making you crazy

[Mesozoic Mister Nigel]

This article is such an awesome example of the beautiful intersection of neuroscience and epidemiology: http://www.theatlantic.com/magazine/archive/2012/03/how-your-cat-is-making-you-crazy/308873/2/

[Mesozoic Mister Nigel]

From the article:

In fact, Sapolsky thinks that Toxo's inventiveness might even offer us some benefits. If we can figure out how the parasite makes animals less fearful, he says, it might give us insights into how to devise treatments for people plagued by social-anxiety disorder, phobias, PTSD, and the like. "But frankly," he adds, "this mostly falls into the 'Get a load of this, can you believe what nature has come up with?' category."

Webster is more circumspect, if not downright troubled. "I don't want to cause any panic," she tells me. "In the vast majority of people, there will be no ill effects, and those who are affected will mostly demonstrate subtle shifts of behavior. But in a small number of cases, [Toxo infection] may be linked to schizophrenia and other disturbances associated with altered dopamine levels—for example, obsessive-compulsive disorder, attention-deficit hyperactivity disorder, and mood disorders. The rat may live two or three years, while humans can be infected for many decades, which is why we may be seeing these severe side effects in people. We should be cautious of dismissing such a prevalent parasite."

The psychiatrist E. Fuller Torrey agrees—though he came to this viewpoint from a completely different angle than either Webster or Flegr. His opinion stems from decades of research into the root causes of schizophrenia. "Textbooks today still make silly statements that schizophrenia has always been around, it's about the same incidence all over the world, and it's existed since time immemorial," he says. "The epidemiology literature contradicts that completely." In fact, he says, schizophrenia did not rise in prevalence until the latter half of the 18th century, when for the first time people in Paris and London started keeping cats as pets. The so-called cat craze began among "poets and left-wing avant-garde Greenwich Village types," says Torrey, but the trend spread rapidly—and coinciding with that development, the incidence of schizophrenia soared.

Since the 1950s, he notes, about 70 epidemiology studies have explored a link between schizophrenia and T. gondii. When he and his colleague Robert Yolken, a neurovirologist at Johns Hopkins University, surveyed a subset of these papers that met rigorous scientific standards, their conclusion complemented the Prague group's discovery that schizophrenic patients with Toxo are missing gray matter in their brains. Torrey and Yolken found that the mental illness is two to three times as common in people who have the parasite as in controls from the same region.

[Mesozoic Mister Nigel]

http://news.nationalgeographic.com/news/2013/01/220113-sneaky-cat-parasite-takes-over-human-brains-science/

Enter Antonion Barragan, a researcher at the Center for Infectious Medicine at Karolinska Institute in Sweden. As Barragan and his team examined toxo in the blood of mice, they found the parasite living in a surprising place: inside the immune cells designed to kill them, a type of white blood cell called a "dendritic cell," after its treelike appearance. "These are the gatekeepers of the immune system," he said. "And we wondered, maybe the parasite is using these cells to get around." Using the cells as Trojan horses. As it turned out, he was right. Toxo was using the immune system cells to travel through the body and get to the host's brain. But how? The immune cells need to be stimulated in order to move—and the toxo itself obviously wasn't getting them going; the cells didn't even seem to know they'd been infected. What was agitating the dendritic cells?

And then they found it: a neurotransmitter called GABA. "It didn't make any sense," Barragan said. "GABA operates in the brain. What's it doing in the immune system?" But there it was. Barragan was seeing something nobody had seen before. Toxo appeared to be inducing GABA production inside the dendritic cells, which excited GABA receptors on the outside of the very same dendritic cells, and sent them zooming through the body, and to the brain. Now, here's the fascinating part: Disturbances in GABA are commonly seen in many psychiatric disorders, including schizophrenia. And elevated GABA levels, Barragan says, "are associated with decreases in fear and anxiety."

Still, Flegr cautions that this discovery doesn't tell the whole story. "I still think the most important molecule is dopamine," he said. "But this GABA mechanism is brand new and very interesting."

And perhaps not surprisingly, given all we've learned about toxo so far, he said, "It's very, very clever."

[Nephew Twiddleton]

 

Whoa. And I thought it was just because we're suckers for things that are cute.

[Anna Mae Bollocks]

Hot and bothered from smelling cat pee? 

[Nephew Twiddleton]

Hot and bothered from smelling cat pee? 

Cheezing needs to be banned. For the Children.

[Mesozoic Mister Nigel]

Whoa. And I thought it was just because we're suckers for things that are cute.

Nope. It's brain parasites.

[The Good Reverend Roger]

Whoa. And I thought it was just because we're suckers for things that are cute.

Nope. It's brain parasites.

I never trusted cats.  Now I know why.

[Mesozoic Mister Nigel]

                                                  /

You love me because your brain is infected with parasites.

[Mesozoic Mister Nigel]

Whoa. And I thought it was just because we're suckers for things that are cute.

Nope. It's brain parasites.

I never trusted cats.  Now I know why.

They're out to take over the world.

[The Good Reverend Roger]

Whoa. And I thought it was just because we're suckers for things that are cute.

Nope. It's brain parasites.

I never trusted cats.  Now I know why.

They're out to take over the world.

HAH!  I just jammed tinfoil up my nose.  They won't get ME.

[Mesozoic Mister Nigel]

Whoa. And I thought it was just because we're suckers for things that are cute.

Nope. It's brain parasites.

I never trusted cats.  Now I know why.

They're out to take over the world.

HAH!  I just jammed tinfoil up my nose.  They won't get ME.

SMART THINKING

I SHOULD GO DO THAT.

[Nephew Twiddleton]

 

[EK WAFFLR]

This explains a lot.

[Mesozoic Mister Nigel]

This explains a lot.

It really, really does, doesn't it?