Fig 1.
Determination of the navigation strategy.
The blue arrows show the preferred direction of movement. R and L means right and left side of the mouse determined based on the body-centered coordinates. The right side of the arena is determined based on the room coordinates. The brown rectangle depicts a vertical wooden post that constituted a landmark together with two walls adjoining the tank.
Fig 2.
Effect of the previous experience with different barriers on the ability to detour the transparent barrier.
Animals that were used in the first part of the experiment (Fig 3) were retrained to detour the same kind of barrier as previously (left side) and next were tested with the transparent barrier (right side). A—picture of opaque, semitransparent and transparent barrier together with the escape platform. B—latency to reach the platform placed behind the barrier. C—diagram presenting the experimental design. The arrow shows the starting point. Values are presented as mean ± SEM.
Fig 3.
Performance of the mice subjected to the inward and outward detour test.
A—transparent group compared with the semitransparent group. B—opaque group compared with the semitransparent group. C—diagram presenting the experimental design. The arrow shows the starting point. $ $ = P < 0.01, $ $ $ = P < 0.001—denotes a significant differences between groups for a given trial; ## = P < 0.01, ### = P < 0.001—denotes significant improvement in the transparent group compared with the first detour trial; *** = P < 0.001 –denotes a significant improvement in the semitransparent group compared with the first detour trial; @ = P < 0.05, @@ = P < 0.01 –denotes a significant improvement in the opaque group compared with the first detour trial. Values are presented as mean ± SEM.
Fig 4.
Perseveration of the mice tested on the detour task.
A—time spent in the barrier zone. B—diagram presenting the experimental design. The arrow shows the starting point. A hatched area depicts the barrier zone. # = P < 0.05, ## = P < 0.01, ### = P < 0.001—denotes a significant increase compared with the last habituation session; ** = P < 0.01, *** = P < 0.001—denotes significant differences compared with the opaque group for a given trial. Values are presented as mean ± SEM.
Fig 5.
Distance between the animal’s path and the central axis of the barrier during the initial approach to the target.
A—diagram presenting measurement of the distance. B—data obtained during the first two days of the experiment (inward detour trials). * = P < 0.05, ** = P < 0.01, *** = P < 0.001—denotes significant differences between the opaque and transparent group; # = P < 0.05, ### = P < 0.001—denotes significant differences between the opaque and semitransparent group; v v = P < 0.01—denotes a significant differences between the transparent and semitransparent group; z = P < 0.05, zz = P < 0.01—denotes significant change in the transparent group compared with the first trial (day 1); $ $ = P < 0.01, $ $ $ = P < 0.001—denotes significant differences in the semitransparent group compared with the first trial (day 1). Values are presented as mean ± SEM.
Fig 6.
Individual performance of the mice from the transparent group.
A and B show tracks of mice displaying a high and low level of perseveration, while C and D shows overall performance of these mice. Large arrows mark data collected from the same mice and identify detour trials depicted in panel A and B, small arrows show the starting point, a hatched area depicts the barrier zone.
Fig 7.
Distance between the animal’s path and the central axis of the barrier during initial approach to the target in animals retrained after the rest period (left side) and next tested exclusively with the transparent barrier (right side).
* = P < 0.05, ** = P <0.01—denotes significant differences between the opaque and transparent group for a given trial; # = P < 0.05, ## = P < 0.01—denotes significant differences between the opaque and semitransparent group; @ = P < 0.05—denotes a significant change in the opaque group compared with the last trial of the retraining phase. Values are presented as mean ± SEM. For more explanations see Fig 5.
Fig 8.
Preference for detouring around the right or left side of the barrier determined based on the body-centered coordinates.
The arrow shows the starting point where the mouse was placed at the beginning of each trial. For more explanations see Fig 1.