title: Sex-dependent neurotransmitter level changes in brains of Toxoplasma gondii infected mice.
abstract: The protozoan parasite Toxoplasma gondii has the ability to alter intermediate host behavior, most impressively the natural aversion to cat scent, to favor the predation by the definitive host. However, the underlying mechanism of the observed phenomenon still remains unknown. Since changes in the neurotransmitter level are postulated as a possible contributing factor, the aim of this work was to assess the monoamine systems activity in specified brain regions involved in the natural defense behaviors, emotion evaluation, and motor and sensory stimuli integration in experimentally T. gondii infected mice compared to uninfected controls. Taking into account the natural differences between genders, the experiments were carried out on both male and female mice. Our results revealed statistically significant changes in all tested monoamine systems with regard to both gender and time after T. gondii invasion. Acute toxoplasmosis was accompanied by a decrease in noradrenergic system activity in females and its slight increase in some brain areas of males. Acute invasion also induced a rise in serotonin system activity, mostly in males. The most striking observation was an increase in the dopamine release noted in acutely infected males. We discuss our results in terms of their possible contribution to T. gondii-induced intermediate host behavior alterations and parasite transmission and with regard to postulated relationship between T. gondii seroprevalence and occurrence of certain disorders such as schizophrenia in humans.
authors.affiliation: Department of Immunoparasitology, University of Lodz, 90-237 Lodz, Banacha 12/16, Poland. gatjus@biol.uni.lodz.pl
authors.forename: Justyna
authors.initials: J
authors.lastname: Gatkowska
authors.forename: Marek
authors.initials: M
authors.lastname: Wieczorek
authors.forename: Bozena
authors.initials: B
authors.lastname: Dziadek
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Dzitko
authors.forename: Henryka
authors.initials: H
authors.lastname: Dlugonska
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D015306:Biogenic Monoamines / Q000378:metabolism*; D001921:Brain / Q000378:metabolism* / Q000469:parasitology; D004298:Dopamine / Q000378:metabolism; D005260:Female; D006790:Host-Parasite Interactions; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D012737:Sex Factors; D014122:Toxoplasma / Q000502:physiology; D014124:Toxoplasmosis, Animal / Q000378:metabolism* / Q000503:physiopathology
chemical_list: D015306:Biogenic Monoamines; D018377:Neurotransmitter Agents; D012701:Serotonin; D004298:Dopamine; D009638:Norepinephrine