Thursday, February 21, 2013

A bag full of cats

When I was pregnant, there were a battery of tests that my doc recommended, among them for a series of potential diseases that might damage the foetus. So, I obediently got them done. One of these tests came back positive: Toxoplasma Gondii. I consulted my trusty What to Expect and was horrified to discover that the thing sounded hugely dangerous. I was traumatised.

The doc recommended I re-do the test and the next one turned out negative ( though why disregard the first and accept the second? Would there be any way of finding out until it was too late?) and all manner of things were well after all.

So this Toxo thing seems like a special parasite, one that was (almost) mine. Naturally, all related reading are of interest. This piece suggests that this parasite - usually considered harmless in healthy adults and reasonably-sized children - actually can cause all kinds of changes in the brain.
She began tagging the parasite with fluorescent markers and tracking its progress in the rats’ bodies. Given the surgically precise way the microbe alters behavior, Webster anticipated that it would end up in localized regions of the brain. But the results defied expectations. “We were quite surprised to find the cysts—the parasite’s dormant form—all over the brain in what otherwise appeared to be a happy, healthy rat,” she says. Nonetheless, the cysts were most abundant in a part of the brain that deals with pleasure (in human terms, we’re talking sex, drugs, and rock and roll) and in another area that’s involved in fear and anxiety (post-traumatic stress disorder affects this region of the brain). Perhaps, she thought, T. gondii uses a scattershot approach, disseminating cysts far and wide, enabling a few of them to zero in on the right targets.

To gain more clarity on the matter, she sought the aid of the parasitologist Glenn McConkey, whose team at the University of Leeds was probing the protozoan’s genome for signs of what it might be doing. The approach brought to light a striking talent of the parasite: it has two genes that allow it to crank up production of the neurotransmitter dopamine in the host brain. “We never cease to be amazed by the sophistication of these parasites,” Webster says. 
The whole thing here.


Someone on Twitter said that this explains Naipaul. I give you that observation without comment.

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