Mouse-Toxoplasma Behavior - RNASeq. Brain-Toxo-RNASeq

In rodents, behavioral changes induced by Toxoplasma gondii are interpreted as an adaptive manipulation by the neurotropic protozoan parasite. This phenomenon, termed fatal attraction, selectively favors transmission to the felid definitive host via predation. With the aim of understanding how the parasite induces such specific behavioral alterations, we performed a longitudinal analysis of T. gondii-induced changes on host behavior, physiology and brain transcriptome as well as cyst load and distribution. Using a set of complementary behavioral tests, we provide strong evidence that T. gondii lowers general anxiety in infected mice, increases explorative behaviors, and surprisingly alters predator aversion without selectivity towards felids. Furthermore, we show a positive correlation between the severity of the behaviors monitored and the cyst burden, a burden that indirectly reflects the level of inflammation during brain colonization. Taken together, these findings refute the myth of a selective loss of cat fear in T. gondii infected mice and point towards widespread immune-related alterations of behaviors.