Lifelong Caloric Restriction Increases Working Memory in Mice

Abstract

Caloric restriction (CR) is argued to positively affect general health, longevity and the normally occurring age-related reduction of cognition. This issue is well examined, but most studies investigated the effect of short-term periods of CR. Herein, 4 weeks old female mice were fed caloric restricted for 4, 20 and especially for 74 weeks. CR mice received 60% of food eaten by their ad libitum (AL) fed littermates, and all age-matched groups were behaviorally analyzed. The motor coordination, which was tested by rotarod/accelerod, decreased age-related, but was not influenced by the different periods of CR. In contrast, the age-related impairment of spontaneous locomotor activity and anxiety, both being evaluated by open field and by elevated plus maze test, was found aggravated by a lifelong CR. Measurement of cognitive performance with morris water maze showed that the working memory decreased age-related in AL mice, while a lifelong CR caused a better cognitive performance and resulted in a significantly better spatial memory upon 74 weeks CR feeding. However, a late-onset CR feeding in 66 weeks old mice did not ameliorate the working memory. Therefore, a lifelong CR seems to be necessary to improve working memory.

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).…”

Calorie restriction in rodents: Caveats to consider

“…Kuhla et al reported improved learning and memory performance of 19-mo old mice begun on a regimen of 40% CR at weaning (Kuhla et al, 2013). Geng et al initiated 40% CR in 18-mo old rats and noted improved learning and memory in MWM performance at 24 mo (Geng et al, 2007).…”

Caloric restriction suppresses exercise-induced hippocampal BDNF expression in young male rats

“…1). In this study, we intervened by caloric restriction for young rats, because the late-onset of caloric restriction in old mice did not ameliorate the working memory 27) . Nevertheless, it seems that 40% of caloric restriction for young rats in our study might be more severe than we had expected.…”