Fig 1.
Main Open Field parameters for the control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7).
Infected animals exhibited reduced distance moved (a), velocity (b), frequency in the center zone (c) as well as reduced time spend in the central zone of the apparatus (d). * Hym vs Con, p<0.05 (Newman-Keuls test). *** Hym vs Con, p<0.005 (Newman-Keuls test).
Fig 2.
Total numbers of different exploratory behavior: grooming (a) and climbing (b) and the main determinants of stress: urination (c) and defecation (d) in the Open Field test for the control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7). * Hym vs Con, p<0.05 (Newman-Keuls test).
Fig 3.
Spatial learning (day 1–4, trial 1–16) in the control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7) in the Water Maze test.
Latency to the platform is parameter used to specify time to escape from water during acquisition trials using a submerged platform.
Fig 4.
Main results from the first and second probe trial of Water Maze test.
Effect of parasite infection on crossings under previous platform position in SE quadrant on first memory test (a) and crossings under previous (b) and new platform position in NW quadrant (c) during second memory probe trial as well as representative swim trajectory—track plot and heat maps–occupancy plot (d) of control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7) obtained by video-tracking software. Tracking analysis show detailed swim trajectory to determine the number of directed swim movements toward the previous platform position. Heat maps represent weighted occupancy across the entire 60s trial. Hot colors indicate longer dwell times. The platform area in target quadrants SE (old position of platform) and NW (new position of platform) are denoted with a circle. Each column represents the mean ± standard error of mean (SEM). ** Hym vs Con, p<0.01 (Newman-Keuls test).
Fig 5.
Time spent in each four quadrants during the second memory probe trial of water maze (day 10) of control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7).
The horizontal dashed line marks chance performance.
Table 1.
Monoamine and metabolite levels in the CNS structures of control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7) determined by high-performance liquid chromatography.
Table 2.
Aminoacid levels in the CNS structures of control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7) determined by high-performance liquid chromatography.
Fig 6.
Real-time quantitative RT-PCR analyses for control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7).
Gene expression levels represent the mRNA expression for IL-6, IL-10, IL-1β and TNF-α in the hippocampus (a), prefrontal cortex (b), striatum (c) and the cerebellum (d) relative to the control. Values represent the means ± SEM for two experimental groups. * Hym vs Control, p<0.05 (Newman-Keuls test).
Table 3.
Real-time quantitative RT-PCR analyses for control rats (Con, n = 8) and rats infected with H. diminuta (Hym, n = 7).
Gene expression levels represent the mRNA expression for IL-6, IL-10, IL-1β and TNF-α in the hippocampus, prefrontal cortex, striatum and the cerebellum levels relative to the control. Values represent the means ± SEM for two experimental groups.
Fig 7.
The graphical course of the experiment (created with BioRender.com).
15 months after the tapeworm infection, the animals were subjected to behavioral tests, after which the biochemical changes in the structures of the CNS were analyzed using HPLC and RT-PCR.
Table 4.
Sequences of gene specific primers used in Real Time PCR (F-forward, R-reverse).