Parasites in the Brain

This is one scary post, signifying the myriad of "other" factors that affects who were are (to be precise - our brain).

"My interest in the link between parasites and human brain diseases was sufficiently awoken to make me look up some scientific papers on the topic. What I learned - although it is only (very) peripherally a social science matter -, I believe, is interesting enough to warrant a blog post here:

One of the apparently best studied parasites in regards to changes in human behavior (possibly besides certain fungi), are toxoplasmosis gondii; or short Toxo.Toxo's primary claim to fame is that it makes rodents become sexually attracted to cats; (possibly even very big cats,  picture below shows an infected "brave" rat).Toxo's life cycle includes a number potential intermediate warm-blooded hosts, but its main goal is to end up in the stomach of a feline; which is where it reproduces.Inside of intermediate hosts, Toxo can cause severe physiological damage, by attacking muscle tissue as well as the brain.

"Toxo goes to work immediately after infecting the brain.
Known effects seem to include almost any behavior you could think of, but one thing that struck me is that Toxo seems to have it out for the men, more than for women. Look at this list of effects for men - reduced brain function, increased jealousy, introspectiveness, boredom; reduced psychomotor activity and reaction times, increased emotional instability, suspicion, and short temperdness; lowered self-esteem, and disregard for social rules.Additionally, men also become more prone to guilt and start showing greater group dependency after infection with Toxo."

Women on the other hand show greater self-esteem, and exhibit more intelligence, awareness, cordiality, amicability, attentiveness to others, loyalty and self-sufficiency. Women reportedly also become more sentimental, socially precise and affective. (Toxo does appear, however, to be linked with schizophrenia in women more often than in men).

One very well documented side effect of Toxo infection, for both men and women, concerns loss of psychomotor skills, lack of concentration and increased risk taking. Indeed the effect are so dramatic that

T. gondii were significantly associated with traffic accidents and in the Czech Republic and the risk for car accidents is 2.65 times greater in infected individuals, no matter if they were drivers or passengers."