Treadmill Exercise as a Preventive Measure Against Age-Related Anxiety and Social Behavioral Disorders in Rats: When Is It Worth Starting?

Objective To determine the appropriate time points to start regular exercise which could reduce age-related anxiety and impaired social behavior. Methods For this study, 8-week-old male Wistar rats were divided into three groups: no exercise (NoEX), shortterm exercise (S-Ex), and long-term exercise (L-Ex) groups. S-Ex-group rats started treadmill exercise at 12 months of age, while L-Ex rats started from at 2 months of age. Exercise rats were forced to walk on the treadmill three times per week, with 1- to 2-day intervals for 10 minutes during the first 2 weeks, at 10 m/min until 17 months of age, and at 8 m/min thereafter. At 19 months of age, behavioral tests were performed to assess the effects of exercise on age- induced behavioral change as well as quantitative polymerase chain reaction were done to uncover the mechanism behind the behavioral changes. Results Anxiety-like behavior was improved by long-term exercise. Additionally, rats belonging to the S-Ex and L-Ex groups showed improved social behavior and increased curiosity about interesting objects. The qPCR data showed that treadmill exercise suppressed the expression of immediate-early genes in the prefrontal cortex of the aged rats. Conclusion This study suggests that long-term exercise represses early response genes, and in this way, it increases resistance to stress, diminishes anxiety-related behavior, and improves social behavior. These findings underscore the need to consider appropriate time to start exercise to prevent stress induced anxiety related behavior.

Automated summary

This study suggests that long-term exercise represses early response genes, increases resistance to stress, diminishes anxiety-related behavior, and improves social behavior.