Are tiny parasites messing with our brains?
Are tiny parasites messing with our brains? Think before you swallow Peter Frost \ Reverie , 1872, Edward Radford (Wikicommons) Toxoplasma gondii is a tiny protozoan. It’s also a parasite. Like a surprising number of parasites, it can infiltrate brain tissue and make its host behave in ways that help it spread to new hosts. For example, an infected rat is attracted to the smell of cat urine and ends up getting eaten by a cat, the only host in which T. gondii can sexually reproduce. Once inside a host, the parasite targets the amygdala—an area of the brain that stores emotional memories. Autopsies of infected rodents show twice the density of T. gondii cysts in the amygdala as in other brain regions ( Vyas et al., 2007 ). Primates can also get infected, and the behavioral changes are similar. Infected chimpanzees like the smell of leopard urine ( Poirotte, 2016 ). Although a feline species is the only host in which T. gondii can sexually r...