The test that is based on two conflicting innate tendencies: exploring a novel environment and avoiding elevated and open spaces constituting situations of predator risk.
The apparatus consists of two open (stressful) and two enclosed (protecting) elevated arms that form a “plus” or cross. Security is provided by the closed arms whereas the open arms offer exploratory value. When anxious, the natural tendency of rodents is to prefer closed dark spaces to opened brightly lit spaces. In this context, anxiety-related behavior is measured by the degree to which the rodent avoids the closed arms of the maze.
Time spent in exploring enclosed versus open arms indicates then the anxiety level of the animal. When placed into this apparatus, naïve mice and rats will, by nature, tend to explore less the open arms due its natural fear of heights and open spaces.
Experimental procedure
In practice, the test consists in placing the subjects individually in the centre of the apparatus facing the open arm and allow to explore the maze freely for 5 min.
Please find bellow a list of standard parameters recorded in this test and related meaning for data interpretation.
|
Registered data |
Data meaning |
|
Number of entries into the zones |
Total number of entries in closed arms = activity index Number of entries into open arms = anxiety index |
|
% number of entries into the zones respect to the total number of entries |
% number of entries into open arms = anxiety index |
|
Permanence time in the zone |
Time spent in open arms = anxiety index |
|
% of permanence time in the zone respect to the total duration of the experiment |
% of time in open arms = anxiety index |
|
Distance covered by the subject |
Quantitative evaluation of locomotor activity |
|
Time spent in immobility |
Qualitative evaluation of locomotor activity |
|
Time spent moving slowly |
Qualitative evaluation of locomotor activity |
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Tine spent moving fast |
Qualitative evaluation of locomotor activity |
|
% of time spent immobile respect to the total duration of the experiment |
Qualitative evaluation of locomotor activity |
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% of time spent moving slowly respect to the total duration of the experiment |
Qualitative evaluation of locomotor activity |
|
% of time spent moving fast respect to the total duration of the experiment |
Qualitative evaluation of locomotor activity |
|
Mean speed of subject displacement = distance covered divided by unit of time (including periods in which the subject is immobile) |
Qualitative evaluation of locomotor activity |
|
Mean speed of subject displacement = distance covered divided by unit of time (only consider subject displacements; excluding periods immobility) |
Qualitative evaluation of locomotor activity |
|
Maximal speed reach by the subject |
Qualitative evaluation of locomotor activity |
|
Minimal speed reach by the subject |
Qualitative evaluation of locomotor activity |
|
Number of occurrence of the Rearing |
Registering of exploration behavior (rearing) or any other user-defined behavior |
|
Total duration of the registered rearing |
Registering of exploration behavior (rearing) or any other user-defined behavior |
The data can be recorded manually or using automated system such as video-tracking system or photobeams systems.
