Age difference of response strategy in radial maze performance of Fischer-344 rats

Age and sex differences in learning performance in an 8-arm radial maze were examined in Fischer-344 rats (aged: 22-27 months; young: 3-4 months). Results of total responses and initial correct responses showed impaired performance in aged rats. There was a sex difference only in initial correct responses of the aged group. In agreement with findings of previous studies, these results demonstrated deficits of spatial learning performance in aged rats. A response strategy was examined as a factor which may affect radial maze performance. Our results revealed that age groups utilized different response strategies to solve the task and appeared similar to reports of maze performance of young animals with experimentally impaired cholinergic function. The results suggest that age difference in a response strategy is due to deterioration of cholinergic system in aged rats, and factors which may have a relationship with the impaired performance in aged rats were discussed, including alteration of response strategy.