Effect of Aging On Emotional Learning And Memory In Male Mice Used As Animal Model of Anxiety

Abstract

[LANGUAGE= "English"] Purpose: The aim of this study was to evaluate learning and memory in the elevated male T-maze, used as the animal model of anxiety. Inhibitory avoidance representing learned fear (emotional learning) is measured by recording the time taken to leave the enclosed arm in 3 consecutive trials. Unconditioned fear (initial fear) is evaluated by recording the time to escape from the open arm, associated with panic disorder.

Materials and Methods: Elevated T-maze consists of 3 arms of equal dimension elevated 38.5 cm from the floor. Young adult (3 month old) and aged (18 month old) mice were used in the experiment.

Results: The avoidance 1 and 2 latency increased in both the young and aged rats. Baseline latency did not change with age although inhibitory avoidance latency shortened in the aged rats. Escape latency was much shorter in the young rats than in the aged rats.

Conclusion: These results showed that the latency of avoidance and escape responses reflected two types of fear/anxiety and differed with age; learned fear improved and escaped latency shortened in the aged rats. Therefore, there were significant differences between young and aged rats in the performance of behavioral tasks in the elevated T-maze. Learned and initial fear were distributed by aging so we concluded that age can effect behaviour in animal models.

Alternate abstract:

Purpose: The aim of this study was to evaluate learning and memory in the elevated male T-maze, used as the animal model of anxiety. Inhibitory avoidance representing learned fear (emotional learning) is measured by recording the time taken to leave the enclosed arm in 3 consecutive trials. Unconditioned fear (initial fear) is evaluated by recording the time to escape from the open arm, associated with panic disorder.

Materials and Methods: Elevated T-maze consists of 3 arms of equal dimension elevated 38.5 cm from the floor. Young adult (3 month old) and aged (18 month old) mice were used in the experiment.

Results: The avoidance 1 and 2 latency increased in both the young and aged rats. Baseline latency did not change with age although inhibitory avoidance latency shortened in the aged rats. Escape latency was much shorter in the young rats than in the aged rats.

Conclusion: These results showed that the latency of avoidance and escape responses reflected two types of fear/anxiety and differed with age; learned fear improved and escaped latency shortened in the aged rats. Therefore, there were significant differences between young and aged rats in the performance of behavioral tasks in the elevated T-maze. Learned and initial fear were distributed by aging so we concluded that age can effect behaviour in animal models.