Infection of male rats with Toxoplasma gondii induces effort-aversion in a T-maze decision-making task

Brain Behav Immun. 2016 Jan 16. pii: S0889-1591(16)30015-0. doi: 10.1016/j.bbi.2016.01.015. [Epub ahead of print]

Tan D¹, Vyas A².

Rats chronically infected with protozoan Toxoplasma gondii exhibit greater delay aversion in an inter-temporal task. Moreover Toxoplasma gondii infection also results in dendritic atrophy of basolateral amygdala neurons. Basolateral amygdala is reported to bias decision making towards greater effortful alternatives. In this context, we report that Toxoplasma gondii increases effort aversion in infected male rats. This host-parasite association has been widely studied in the context of loss of innate fear in the infected males. It is suggested that reduced fear towards predators reflects a parasitic behavioral manipulation to enhance trophic transmission of Toxoplasma gondii. Observations reported here extend this paradigm away from a monolithic change in fear and towards a multi-dimensional change in decision making.
Copyright © 2016. Published by Elsevier Inc.

KEYWORDS:

Behavioral manipulation; Decision making; Effort discounting; Operant learning; Parasites

PMID:

26783701

[PubMed - as supplied by publisher]