title: Toxoplasma gondii infection and testosterone congruently increase tolerance of male rats for risk of reward forfeiture.
abstract: Decision making under risk involves balancing the potential of gaining rewards with the possibility of loss and/or punishment. Tolerance to risk varies between individuals. Understanding the biological basis of risk tolerance is pertinent because excessive tolerance contributes to adverse health and safety outcomes. Yet, not much is known about biological factors mediating inter-individual variability in this regard. We investigate if latent Toxoplasma gondii infection can cause risk tolerance. Using a rodent model of the balloon analogous risk task, we show that latent T. gondii infection leads to a greater tolerance of reward forfeiture. Furthermore, effects of the infection on risk can be recapitulated with testosterone supplementation alone, demonstrating that greater testosterone synthesis by the host post-infection is sufficient to change risk tolerance. T. gondii is a frequent parasite of humans and animals. Thus, the infection status can potentially explain some of the inter-individual variability in the risky decision making.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
authors.forename: Donna
authors.initials: D
authors.lastname: Tan
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore. Electronic address: avyas@ntu.edu.sg.
authors.forename: Ajai
authors.initials: A
authors.lastname: Vyas
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003657:Decision Making / Q000187:drug effects*; D007175:Impulsive Behavior / Q000187:drug effects; D008297:Male; D009919:Orchiectomy; D051381:Rats; D017208:Rats, Wistar; D012201:Reward; D012309:Risk-Taking; D013739:Testosterone / Q000097:blood / Q000494:pharmacology*; D014123:Toxoplasmosis / Q000503:physiopathology* / Q000523:psychology*
chemical_list: D013739:Testosterone
keywords: BART; Behavioral manipulation; Decision making; Impulsivity; Parasitism; Steroids