Modifications in host fear-related behaviour in the elevated plus maze are independent of AaaH2 TH in the parasite. (A) Infected animals exhibited a similar increase in the distance covered in this setup, in comparison to controls. (B) Speed values were equally higher in both infected groups, relative to controls. (C) Infected mice were able to cover longer distances in the open arms than control mice. (D) Control animals preferred closed arms over open arms whereas animals in both infected groups did not show this occupancy bias. (E) Visit duration to closed arms was increased in controls and this difference was not detected in infected mice. (F) Differently from controls, infected animals showed a higher number of visits to the extremity of the open arms. (A–F) Mouse saline group, n = 28; TgWT group, n = 15; TgAaaH2KO group, n = 25. *p < 0.05. The data are presented as the mean ± SEM.