Food restriction increases long-term memory persistence in adult or aged mice

Food restriction (FR) seems to be the unique experimental manipulation that leads to a remarkable increase in lifespan in rodents. Evidences have suggested that FR can enhance memory in distinct animal models mainly during aging. However, only few studies systemically evaluated the effects FR on memory formation in both adult (3-month-old) and aged (18-24-month-old) mice. Thus, the aim of the present study was to investigate the effects of acute (12 h) or repeated (12 h/day for 2 days) FR protocols on learning and memory of adult and aged mice evaluated in the plus-maze discriminative avoidance task (PM-DAT), an animal model that concurrently (but independently) evaluates learning and memory, anxiety and locomotion. We also investigated the possible role of FR-induced stress by the corticosterone concentration in adult mice. Male mice were kept at home cage with food ad libitum (CTRL-control condition) or subjected to FR during the dark phase of the cycle for 12 h/day or 12 h/2 days. The FR protocols were applied before training, immediately after it or before testing. Our results demonstrated that only FR for 2 days enhanced memory persistence when applied before training in adults and before testing in aged mice. Conversely, FR for 2 days impaired consolidation and exerted no effects on retrieval irrespective of age. These effects do not seem to be related to corticosterone concentration. Collectively, these results indicate that FR for 2 days can promote promnestic effects not only in aged mice but also in adults.