Cordyceps unilateralis has become famous as “the parasite that zombifies ants”, and the Web itself has spread hundreds of images in which we see ants completely enslaved and controlled by a monstrous fungus growing out of their heads. At first it was believed that the fungus exerted some kind of direct mental control over the ant; however, a new study published by the universities of Pennsylvania and Notre Dame indicates that the fungus leaves the ant's brain intact and behaves more like a “puppeteer”…
There are different types of parasitism, and some are much more chilling than others. Among the lighter variants we find brood parasitism, in which certain birds basically “steal nests” and leave the raising of their offspring to other species. But then there are cases like Cymothoa exigua, an isopod that attaches to the tongue of fish and replaces it entirely, parasitoid wasps (highly appreciated in pest control) that inject their eggs into other insects… and our “friend” the fungus, Cordyceps unilateralis.
Once this fungus takes control of an ant (which generally belongs to the tribe Camponotini), it forces it to leave its home and permanently attach itself to the surface of a leaf. From there, all the fungus does is grow until it pierces the ant's head and reaches the conditions necessary to release its spores, repeating the cycle. The complete process can take ten days, and the truth is that it fascinates scientists, not only for its medicinal potential, but also because they want to know exactly how the fungus works. Due to its growth in the ant's head, Cordyceps unilateralis has been identified on several occasions as “the brain parasite”… but it might not be quite like that.
A new study published by researchers from the universities of Pennsylvania and Notre Dame combined the power of electron microscopes, three-dimensional visualization, artificial intelligence and machine learning, establishing that Cordyceps unilateralis leaves the ant's brain virtually intact, and controls the actions of its host by infiltrating muscle fibers. In other words, it is “a fungus wearing an ant suit”, which manipulates its victim peripherally.
Still, this discovery generates more questions than answers. Why doesn't the fungus intervene in the ant's brain? Does it affect it with its chemistry, or is it enough to invade every muscle and every limb of its body? The researchers have a hypothesis: Cordyceps unilateralis needs the ant alive to move to its final location. Another possibility is that the fungus requires certain “computational power” from the brain. The point is that the zombie ant is not entirely zombie, and the brain parasite does not work that way. Personally, I feel much more uncomfortable now, knowing that the ant is not an unconscious zombie, but rather is invaded and conquered at the muscular level. That said, here is your nightmare fuel. Images!
Nightmare fuel: the gallery
Source: Gizmodo
Access the study: PNAS
