Long-lived mice exhibit 24 h locomotor circadian rhythms at young and old age

alpha MUPA transgenic mice exhibit spontaneously reduced eating and increased life span compared with their wild type (WT) control FVB/N mice. alpha MUPA mice also show high-amplitude circadian rhythms in food intake, body temperature, and hepatic clock gene expression. Here we examined young and aged WT and alpha MUPA mice for the period of locomotor activity (tau) under total darkness (DD). We show that tau changed in WT mice from a period <24 h at 8 months to a period >24 h at 18 months. However, the period of alpha MUPA mice was similar to 24 h at both 8 and 18 months. As deviation of tau from 24 h has been found to be inversely related to life span in a large number of rodents, our results suggest that the sustainable endogenous period of similar to 24 h in alpha MUPA mice may contribute to their prolonged life span. (C) 2011 Elsevier Inc. All rights reserved.