Amelioration of learning impairment by docosahexaenoic acid in SAMP 8 mice

Abstract

Using SAMR 1 and SAMP 8 mice, we studied the relation between learning impairment and senescence, individual variations in senility, and the effects of oral administration of docosahexaenoic acid (DHA, n-3 PUFA) on learning and memory impairment. When we studied learning and memory impairment as a model of disorders using the passive avoidance task, we found that mice with a lower grading score were more successful at achieving learning. Changes in learning and memory ability were related to age as well as senescent characteristics, and the turning point for the senescent process in SAMP 8 mice was between 27 and 42 weeks of age. The incidence of learning impairment was decreased when SAMP 8 mice were fed diets containing DHA. These results indicate that we should correct experimental data in chronological age for differences in individual biological age (senescent characteristics). DHA was effective against learning and memory impairment in SAMP 8 mice, and delayed the onset of senility.