Long-term caloric restriction in mice may prevent age-related learning impairment via suppression of apoptosis

Caloric restriction (CR) is the most reliable intervention to extend lifespan and prevent age-related disorders in various species from yeast to rodents. However, the underlying mechanisms have not yet been clearly defined. Therefore, we aimed to identify the underlying mechanisms of long-term CR on age-related learning impairment in C57/BL mice. Thirty six-week-old male C57/BL mice were randomly divided into three groups: normal control group (NC group, n=10), high energy group (HE group, n=10), and CR group (n=10). After 10 months, the Morris water maze test was performed to monitor learning abilities. Western blotting, immunohistochemistry and real-time polymerase chain reaction were used to monitor changes in protein and mRNA levels associated with apoptosis-related proteins in the hippocampus. The average escape latency was lower in the CR group compared with the NC group, and the average time taken to first cross the platform in the CR group was significantly shorter than the HE group. Both Bcl-2 protein and mRNA expression levels in the CR group were significantly higher than those of the NC group and HE group. The expression of Bax, Caspase-3 and PARP protein in the CR group was significantly lower than the NC group. Our findings demonstrate that long-term CR may prevent age-related learning impairments via suppressing apoptosis in mice.