Toxoplasma, testosterone, and behavior manipulation: the role of parasite strain, host variations, and intensity of infection

Abstract

Toxoplasma gondii is an intracellular parasite involved in the etiology of various behavioral and hormonal alterations in humans and rodents. Various mechanisms, including induction changes of testosterone production, have been proposed in the etiology of behavioral alterations during T. gondii infection. However, controversy remains about the effects of T. gondii infection on testosterone production; in some studies, increased levels of testosterone were reported, whereas other studies reported decreased levels. This is a significant point, because testosterone has been shown to play important roles in various processes, from reproduction to fear and behavior. This contradiction seems to indicate that different factors—primarily parasite strains and host variations—have diverse effects on the intensity of T. gondii infection, which consequently has diverse effects on testosterone production and behavioral alterations. This paper reviews the role of parasite strains, host variations, and intensity of T. gondii infection on behavioral alterations and testosterone production, as well as the role of testosterone in the etiology of these alterations during toxoplasmosis.

Key words： Toxoplasma gondii; testosterone; behavior manipulation; parasite strain; host variations; intensity of infection; neurologic and psychiatric disorders

Acknowledgments

The author would like to sincerely thank Professor Jaroslav Flegr (Charles University, Prague, Czech Republic) for their excellent comments and helpful suggestions. The author also expresses his sincere thanks to the unknown referees for valuable criticisms and suggestions.

Compliance with ethics guidelines

Amir Abdoli declares that he has no conflict of interest.

ƒThis manuscript is a review article and does not involve a research protocol requiring approval by the relevant institutional review board or ethics committee.

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