Cat Parasite Reduces General Anxiety in Infected Mice

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There are a lot of people out there who will have heard of Toxoplasma gondii. In short, it is a parasite that uses cats as well as other felids as definitive hosts. However, it is capable of speading to just about all warm-blooded animals out there, with humans being no exception to this particular rule. Due to this, people can pick up toxoplasmosis by becoming infected with Toxoplasma gondii. Since the parasite is so connected to cats, it should come as no surprise to learn that coming into contact with the contaminated feces of infected cats is one of the most common causes of toxoplasmosis. However, there are other potential causes, with examples ranging from eating undercooked meat to having become infected while still in the womb.

Generally speaking, toxoplasmosis won’t produce noticeable signs and symptoms in people who have been infected. However, there are some people who will show signs and symptoms that are very similar to those of the flu, meaning that it can be difficult for them to distinguish between that and toxoplasmosis. Furthermore, while most people will be fine, those with weakened immune systems can experience more dangerous signs and symptoms that include but are not limited to confusion, seizures, lung problems, and the inflammation of their retinas. Having said that, for a lot of people, what spooks them the most about toxoplasmosis would be the behavioral changes that it may or may not be capable of inducing in humans.

Parasites changing the behaviors of their hosts is very common. Since humans are still animals, this means that we are not exempt from such things happening to us no matter how scary the prospect might be. Currently, it hasn’t been confirmed that Toxoplasma gondii causes humans to become more willing to take risks, but there seems to be a correlation. On top of that, there seems to be a correlation between Toxoplasma gondii and various unpleasant neurological phenomena as well, which makes it no wonder that so many people find the parasite to be concerning.

What Is the Latest Finding On Toxoplasma Gondii?

The latest finding on Toxoplasma gondii is connected to this issue in an indirect sense. Moreover, it is rather exciting in its own right because it could overturn a good chunk of what was considered orthodox understanding about the parasite. In short, it was thought that Toxoplasma gondii caused infected rodents to become less afraid of cats and other felids in particular, thus facilitating the complicated life cycle of the parasite. Initially, researchers wanted to look into the molecular mechanism by which said phenomenon is executed. However, when they examined the inconsistent, contradictory, and otherwise un-useful findings on the effects of Toxoplasma gondii on infected rodents, they decided to examine the orthodox understanding of the matter for increased clarity. As it turned out, their findings suggest that Toxoplasma gondii doesn’t actually make infected rodents less afraid of cats and other felids. Instead, the parasite makes infected rodents less afraid in general.

How Did the Researchers Manage to Figure This Out?

The researchers didn’t run a single test on the matter. Instead, they ran a number of tests. For example, they put both infected and uninfected rodents in a maze to see their response, which revealed a couple of things. One, the infected mice were more willing to explore new environments. Two, the infected mice were more willing to interact with objects when compared with their uninfected counterparts. Likewise, the researchers used their hands to simulate the introduction of a potential threat. The infected rodents showed little hesitation in interacting with it. In contrast, the uninfected rodents showed clear signs of avoidance, defensiveness, and even stress in the presence of the potential threat. Finally, infected rodents didn’t show any particular preference for felids over other species capable of posing a threat. Yes, they were willing to investigate to bobcat urine. However, they were just as willing to investigate fox urine and guinea pig urine. On top of that, infected mice showed no hesitation about interacting with an anesthetized rat, whereas their uninfected counterparts froze in fear under the same circumstances.

Besides this, it is interesting to note that the researchers also made an effort to map the brains of the infected rodents. Something that produced some interesting results. For instance, it seems that the extent of the behavioral changes caused by the parasite were correlated with the number of cysts as well as the extent of neuronal inflammation. However, the locations of these phenomena weren’t concentrated in specific parts of the brain but instead saw considerable variation from infected rodent to infected rodent, thus suggesting that the spread of the infection wasn’t particularly directed.

Does This Mean Anything?

It can be said that these findings both change a lot and change not much at all. First, it overturns the notion that the parasite specifically targets the infected rodents’ fear of cats and other felids, which is huge. However, that is just the scientific process working out the way that it should. Simply put, scientists are always seeking to develop a better understanding of the world around us, which involves a great deal of experimentation. Sometimes, their findings will contradict what was previously believed to be true, thus prompting further investigation into the matter. Should those findings prove to be well-founded, they will become the new orthodox understanding of the relevant topic. As such, these findings can be seen as cause for celebration because they mean a better understanding of the parasite, provided that they are supported by further research into the matter.

Having said that, these findings don’t mean that the parasite isn’t adapted for its circumstances. After all, a less cautious rodent is a much likelier to be eaten rodent, meaning that the infection still facilitates the spread of the parasite as well as the continuation of its life cycle. Besides this, it is interesting to think about what this means for the human hosts of the parasite considering their increased risk-taking, though said speculation means very little without actual experimentation to provide concrete evidence one way or the other. Ultimately, there is still much that remains mysterious about Toxoplasma gondii, meaning that there is still much research that needs to be carried out.