Age and sex affect spatial and emotional behaviors in rats: the role of repeated elevated plus maze test.

The main objective of the study was to investigate the effects of age and sex differences on locomotor activity, learning and memory in rats. Another objective was to investigate whether repeated elevated plus maze tests induce anxiety in rats. Eighty Wistar rats were divided into eight groups according to their sex, age and anxiety status. Locomotor activity was assessed in open field. Repeated anxiety tests were performed in elevated plus maze. Spatial learning and memory were evaluated with the Morris water maze. All behavioral tests were recorded online and analyzed offline with an analytical software. Exploratory behavior was lower in anxiety-induced rats. Male rats had lower anxiety levels, locomotor activity and exploratory behavior compared to females. During the training period of Morris water maze latency to find platform, total distance traveled and average swimming speed decreased in all groups with repeated tests and young rats generally were faster than aged rats. During the probe trial, although the number of platform crossings was not affected, time spent in the platform zone was higher in the young groups compared to the aged groups. In conclusion, age and sex affect locomotor activity, learning and memory in different aspects.