EN
The parasitic protozoan Toxoplasma gondii is capable of altering intermediate host natural defensive behavior, which is believed to facilitate the parasite’s transmission in the environment. Despite extensive research on the subject, the exact mechanism behind the host manipulation remains obscure. However, key neurotransmitter levels are listed among possible contributing factors. Thus, the study was aimed at evaluating the monoaminergic activity in specified brain regions of T. gondii infected mice of both genders. The obtained results show that parasite invasion influences all tested monoamine systems and the observed changes depend on gender and time after infection. The parasiteinduced neurotransmission alterations were mostly pronounced during acute toxoplasmosis and they involved a decrease in noradrenergic system activity in females and its slight increase in some brain areas of males as well as a rise in serotonin and dopamine systems activity in males. These findings may contribute to a better understanding of T. gondii involvement in the host behavior control and in the occurrence of certain CNS disorders in humans. The study was supported by the Polish Ministry of Science and Higher Education (grant N N302 636340)