While some bacteria and parasites are known to have a major impact on the mental health of a person, a recent study indicated that single cell parasite called Toxoplasma gondii, found in cat feces, can result in long-lasting behavioral modifications.
The study, titled “Morbid attraction to leopard urine in Toxoplasma-infected chimpanzees,” carried out by researchers from the Centre d’Écologie Fonctionnelle et Évolutive (CNRS/Université de Montpellier/Université Paul Valéry Montpellier 3/EPHE) found that influence of parasite Toxoplasma gondii is distinct to each host.
The parasite can reproduce only in felines
The study, published online in the journal Current Biology in February 2016, revealed that the parasites that caused toxoplasmosis adopt distinct pathways during their development to adulthood and reproduce in some definite host. While the parasites may find themselves moving from one host to the other, modification in behavior are induced in the hosts the parasites feed on, though similar nature of parasite manipulation is rarely observed in mammals.
However, Toxoplasma gondii has shown exceptions in terms of reproduction and manipulation. The scientists observed that humans, to a large extent, are affected by this parasite which can reproduce only in felines.
Examination of the parasitized rodents shows an extreme modification in their olfactory functions manifested by parasitized mice appearing to be attracted to the odor from cat urine unlike healthy rats. This results in the intermediate host of the parasites, i.e., mice to be preyed on by cats, a feline host.
Presence of the parasite is manifested in affected humans in the form of personality changes, longer time to react and decrease in prolonged concentration levels. Other effects on humans could not be determined as modern humans do not fall prey to felines anymore.
Evolution of Toxoplasma gondii
To understand the impact on behavioral changes on humans, the scientists carried out behavioral tests which have their basis in olfactory cues on chimpanzees, regarded as humans’ last common ancestors. This is because chimpanzees continue to be attacked and eaten by leopards from the feline category.
Assessment of chimpanzees’ behavior showed that the infected ones lost their fear of the leopard when contrasted with the uninfected ones who avoided leopard urine. The same kind of alluring behavior in infected chimpanzees was not observed when they were exposed to the urine of other felines like lions and tigers who are not counted among their natural predators. The results indicated that parasite manipulation caused due to the presence of Toxoplasma gondii is highly specific to each host.
While the findings only further the continuing debate on the origin of behavioral and olfactory changes observed in humans over a period of time, they also help understand the kinds of predation pressures faced by a wide range of species. The observations would also help understand the evolutionary history of Toxoplasma gondii and explain the factors under which the presence of the parasite causes modifications in its hosts.
Scope of recovery
There can be myriad reasons for some people to be affected by different mental health disorders. While most mental disorders can be treated, there are some which still need to be researched upon to find proper cure. Some mental health problems arise due to unknown factors, thus making it imperative to research upon them.
If you know someone suffering from any form of mental illness, contact Sovereign Mental Health Services for assistance. One should not delay the treatment or it can worsen the situation. Contact us at our 24/7 helpline number 866-973-7164 or chat online to know about our mental health centers in California and other states of the U.S.