•  
  •  
 

THE EFFECTS OF VOLUNTARY EXERCISE ON THE CIRCADIAN CLOCK IN AGED AND YOUNG FEMALE MICE

Abstract

The circadian clock regulates essential physiological processes, but aging disrupts this rhythm, increasing the risk of neurodegenerative diseases, diabetes, cardiovascular diseases, and cancer. These risks are amplified by disruptions in hormone release, metabolism, and immune response. Voluntary exercise may counteract circadian disruption, though its mechanisms remain unclear. PURPOSE: This study examined differences in voluntary running times and distances between young and aged female mice under a controlled light/dark cycle, correlating activity with frailty index scores. METHODS: This work was approved by the University of Wyoming IACUC. Three 18-month-old and three 3-month-old female mice were individually housed with running wheels under a 24hour light/dark cycle. Running activity was recorded for two weeks and analyzed using ClockLab. Following the study, mice were sacrificed via intraperitoneal injection, and their brains were extracted for confocal imaging. RESULTS: Aged mice ran significantly less than young mice, with young females (frailty index 0) showing the highest activity levels. Aged females (frailty index 4) showed marked reductions in revolutions and daily distance. Young females exhibited consistent circadian rhythmicity, with activity peaks aligned to the light/dark cycle. Aged females, however, displayed more erratic behavior, with less pronounced peaks and irregular activity patterns. This suggests that aging reduces physical activity and disrupts circadian stability. CONCLUSION: Aging diminishes physical activity due to physiological decline and frailty. These findings highlight the link between frailty, circadian stability, and exercise. Future research should explore interventions such as timed exercise or pharmacological treatments to address age-related declines in activity and associated health risks. This work was supported by NIH Grant 2P20GM12131006.

This document is currently not available here.

Share

COinS