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

Abstract

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 (12h) or repeated (12h/day for 2days) 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 12h/day or 12h/2days. The FR protocols were applied before training, immediately after it or before testing. Our results demonstrated that only FR for 2days enhanced memory persistence when applied before training in adults and before testing in aged mice. Conversely, FR for 2days 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 2days can promote promnestic effects not only in aged mice but also in adults.

Motivational state, reward value, and Pavlovian cues differentially affect skilled forelimb grasping in rats

“…Food restriction of similar levels has been shown to decrease organ pathology and increase longevity in rats (Keenan et al 2005;Rowland 2007). Additionally, food restriction has recently been suggested to affect learning and performance in memory and discrimination tasks (Makowiecki et al 2012;Kuhla et al 2013;Talhati et al 2014). On a more general level, direct effects of food restriction on brain plasticity have been reported (Murphy et al 2014).…”

Aging and brain rejuvenation as systemic events

“…; Talhati et al . ). During long‐term CR applied for 30 weeks, adult mice were shown to have improved spatial learning and memory in the Morris water maze task (Ma et al .…”

“…Similarly, short‐term CR was shown to impair memory consolidation and exert no effect on memory retrieval in aged mice (Talhati et al . ). In humans, while CR improved verbal memory (Witte et al .…”

“…In a second study, short‐term CR was also shown to enhance memory persistence in a discriminative avoidance task in young adult animals when applied before training and in aged animals when applied before testing (Talhati et al . ), indicating age‐dependent differences in the effectiveness of CR. In primates, chronic CR also resulted in improved working memory (Dal‐Pan et al .…”

“…Several studies in animal models have observed beneficial effects of various forms of CR on a variety of cognitive functions such as motor learning and hippocampal-dependent memory (Pitsikas and Algeri 1992;Fontan-Lozano et al 2007;Witte et al 2009;Dal-Pan et al 2011;Ma et al 2014;Talhati et al 2014). During long-term CR applied for 30 weeks, adult mice were shown to have improved spatial learning and memory in the Morris water maze task (Ma et al 2014).…”