Impaired memory following predatory stress in mice is improved by fluoxetine

The first purpose of the present study was to investigate possible effects of predatory stress (i.e., 5-min cat exposure) on short-term learning abilities in Swiss mice using the object recognition test (ORT). The second aim was to evaluate the effects of anxiolytics (i.e., diazepam and fluoxetine) on learning/memory abilities in the ORT following predatory stress. Results showed that predatory exposure impaired learning and produced amnesia of acquired information or impairment to retrieve learned information (48 and 96 h poststressor). The learning impairment in the ORT in stressed mice was restored by acute fluoxetine treatment, but not by diazepam that instead affected learning in nonstressed animals. Taken together, these findings indicate that this animal model of exposure of mice to unavoidable predatory stimuli produces early cognitive changes analogous to those seen in patients with acute stress disorder (ASD).