Can This Parasite That Makes Mice Unafraid Of Cats Stop Other Fears Too?

According to a new study, a parasite usually found in cats that can eliminate mice’s fear of felines can hijack their brain in such fatal way that it can stop their other fears and even make them reckless in all sorts of scenarios.

Quashed Fears

The parasite in question, known as Toxoplasma gondii, is a single-celled parasite commonly found in felines, as well as most species of warm-blooded animals and humans. Per the study, published Tuesday in the scientific journal Cell Reports, the parasite can make mice unafraid of cats but doesn’t stop there since it can make the animals more reckless. In fact, the study found that infected mice spent more time in areas that were out in the open, which are exposed places that uninfected mice usually avoid and steer clear of, as well as explore the scents of foxes and relatively harmless guinea pigs.

And when it comes to boldness, infected mice also were brave enough to prod the hand of an experimenter inside a cage, which is something that uninfected mice steered clear of, even driving them to the other side of the cage. Infected mice were also relatively unfazed by an anesthetized rat, which is a common predator.

Per the report made by the researchers, the extent of the T. gondii infection in mice seemed to track with their behavioral changes. The extent is measured by the number of parasite cysts that are observe in their brains.

 But more studies are needed to fully understand the infection and how it can affect mice in the long run, according to the researchers.

T. Gondii

As a protozoan parasite, T. gondii needs to get into the guts of cats (which are their definitive hosts) to sexually reproduce. However, other animals can become infected by ingesting the parasite or by direct (or indirect) contact with feline feces. From there, the parasite would then spread in the body and quickly form cysts in the host’s brain.

While there are cases of people that can get infected of T. gondii, the effects are not as severe as mice.

mice-800875_1920 Mice can feel each other's pain. Image courtesy of Pixabay, public domain