Effects of arachidonic acid on the spatial cognition of aged rats

To examine the effects of arachidonic acid (AA) on age-related cognitive deficits, Fischer 344 rats were given an AA-supplemented powder diet for 12 weeks from 18.6 months old as part of the old AA (OA) group. Other age-matched rats were fed a non-AA-supplemented powder diet as part of the old control (OC) group, and young rats were fed lab pellets as part of the young control (YC) group. When the aged rats reached 20.0 months old, all animals were tested for spontaneous activity in an open field, followed by the Morris water maze place and cue tasks. Escape latencies for the place task showed that the YC rats were fastest, and there was no difference between the OA and OC groups. However, the probe test and the first block of the cue task indicated that the OA rats remembered the location of an invisible platform better than the OC rats. Although the amount of hippocampal AA was larger in the OA rats than in the OC rats, the difference was not significant. The results showed that AA administration to aged animals may alleviate age-related deficits in spatial cognition.